Those of you who've been following the falconry season on Facebook know that our Red Tail of three seasons, Lily, started signaling that she was thinking about moving on.
Sure, she was still her feisty little self and still behaved the same when handled but you could tell her heart wasn't really in it like in prior years. This was most evident in the field as a reluctance to follow, less enthusiasm on the chase, and a propensity to wander off on her own.
In the end, it's always the bird's choice as to come back (or not) and Lily clearly had things on her mind beyond just the hunting season.
Once we've made the decision to release her, there are a couple things still to consider: her condition, timing, and release site.
As fas as conditioning goes, we want her to be both in decent athletic shape and a bit heavier than her true flying weight on release day. This means we needed to work her / hunt her for at least a couple weeks at flying weight to build up her conditioning again after the molt followed by a couple days of extra feeding to bump her up 15-20% above her ideal hunting weight. This will give her a "cushion" of energy reserve as it often takes a couple days to re-acclimate to the wild and begin hunting consistently on her own.
As to timing and release site, the regulations largely leave this up to the individual falconer's discretion. Our primary concerns here: decent prey availability and decent weather. This puts the dead of winter right out, but also usually the summer too as we don't want to interfere with a normal molt. So in practical terms, we're talking about spring and fall at or near peak migration times.
Having checked all the boxes, yesterday was the day! The place we'd picked out for her is a large (like 30,000 acres) hay farm surrounded by rolling sage hills. I've trapped birds there before and it's a perfect spot for a fall release. There is an endless supply of rodents and right now there are probably 400 raptors staging there. She'll be able to stay over the winter if she likes (about 50 or so do) or follow along on the main migration.
Here are a few pics of our last time out:
Here is the release video and a couple post-release pics. I followed her along for about a quarter mile until she'd found a good high perch, then left her there.
She's always been just about the most photogenic animal I've ever been around and I'll leave you with my favorite portrait of her (and one of my fav pics of all time):
Good luck Lily!
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This season is shaping up to be quite the challenge - many of our favorite spots fell to wildfires over the summer and so we've had to scramble to find new hunting areas. The weather has also been atypically awful for early fall with temps consistently in the 20*s and a nearly constant wind.
Nonetheless, the HAHAs continue to shine! I do not intend to post weekly this year, but will episodically update everyone as the season progresses.
For now, here are a few portraits from September:
Early exuberance = broken T-perch:
The raptor nesting season typically runs from mid-March to early July each year and my time commitments there will make continuing this weekly blog rather challenging. As such, I think this will be the last regular Falconry Friday installment until we start flying again in August. I'll continue to periodically post updates on the progress of Cedric the GHO (he came to the glove for food for the first time yesterday!) as well as any other interesting topics that crop up (pun intended).
In many ways, this post does bring us full circle - we started in August 2016 with a newly captured juvenile hawk and followed her through her first year hunting as a falconry bird. This post will serve as an outline for how that hawk made it from an amorous wink to egg to fledgling to the present.
Given that Cornell's red tailed hawks Big Red and Ezra are the stars of the show, we'll use red tails living in the northern latitudes for the following timeline .
For those interested in the historical timetable data for their five previous on-camera nesting seasons, this handy table was produced by Cornell volunteer Elly K.
Also by Elly K. , here is a photo essay on identifying Big Red (the female) and Ezra (the male).
And here are two maps of the nesting area on the Cornell Campus: map #1 , map #2
Finally, see Cornell's RT nest FAQ Page for additional questions not covered below.
(Image credit for the nesting photos below: Cornell Lab of Ornithology, 2013-2016)
Mating and Nesting
Most hawks in the northern U.S. will begin establishing a territory and courting as early as January. This will be followed by mating multiple times in late February and early March. Nest site selection is initially the male's responsibility and he will typically have 1-3 locations selected to present to the female, who will make the final decision on the current year's site.
The pair will begin nest building in earnest in early March with most of their on-nest activity occurring in the mornings. They will begin building (or refurbishing) the nest platform with locally harvested sticks, arranging them into the form of a nest cup. As egg laying approaches, they will begin supplementing the stick deliveries first with strips of bark that will be worked into the nest cup to form a soft, insulated bowl for the eggs. Finally (and continuing through incubation) they will further supplement the nest cup with fresh evergreens, which serve two functions: (1) to advertise the nest's occupancy and (2) evergreens have anti-fungal, anti-bacterial, and anti-parasitic properties thought to help protect the youngsters-to-be.
Egg Laying and Development
Most hawks in the northern U.S. will lay from one to three eggs, with kestrels and ferruginous hawks being the clear outliers laying up to six eggs.
The first egg is typically laid in mid-March with subsequent eggs laid approximately 4 days apart. This interim period is often referred to as soft incubation in that the parents are keeping the eggs warm enough to preserve viability but not warm enough to begin internal development of the embryo.
Hard incubation begins with the last egg laid and will keep the nest cup at 98*F and 43% humidity for the duration of the 28-40 day incubation period. The nest cup at this stage is just large enough the adult hawk's body to form a tight cap on top. Most of the incubation will be performed by the female. The male will bring food to the nest, which the female will typically eat off-site - absences that give the male his only real "nest time".
During incubation, the parents will rotate the eggs every couple hours -- a vital function given that the membranes surrounding the embryo within the egg (the chorion and allantois) will fuse and kill the embryo were the egg to be left stationary.
The following is a synopsis of the embryo's development within the egg during this incubation period:
--The allantoic membrane develops very early in incubation. It originates in the embryo's developing G.I. tract and protrudes out through the umbilicus, fusing with a second membrane (the chorion) which envelopes both the embryo and the yolk sac. Together, they provide the embryo with it's oxygen supply via diffusion through the shell, along the blood vessels lining the chorioallantoic membrane, through the umbilicus, and into the embryo's bloodstream.
--The embryo's heart starts to beat within 72 hours of the start of hard incubation. Initially the heart has only two chambers, but quickly differentiates into four chambers.
--By day 11, the embryo has doubled in size, the ear opening is visible, and the skin has taken on a texture that delineates the future feather tracts (pterylae). The bones of the skull and the feet are also becoming visible.
--By day 12, tail feathers are visible and by day 14 feathers cover most of the embryo's body.
--By day 15-16, the beak has hardened and the attached egg tooth has formed, the leg scales are present, and ratio between body and limb size is balancing out.
--By day 18 the albumin supply has been exhausted and the embryo's sole nutrition source is now the yolk sac.
--By day 10-20 the eyelids are fully formed and the embryo turns it's head towards the large end of the egg, beak under right wing, with feet drawn up.
--During this time, the embryo has drawn some calcium from the shell as well as lost a fair amount of moisture through diffusion -- the egg actually weighs less now that at the start of incubation! An air space has developed outside of the chorioallantoic membrane but within the shell due to this loss of fluid.
--Soon the yolk sac will be drawn into the abdomen and the umbilicus will close. The chorion no longer provides enough oxygen to the embryo and carbon dioxide begins to build up. This build up of carbon dioxide causes the embryo's neck muscles to twitch, which in turn causes the egg tooth on the beak to puncture the chorionic membrane, allowing the embryo to breathe in the air space within the shell. Hatching has begun and can take up to 72 hours to complete, although 36 hours is more typical!
-- Carbon dioxide continues to accumulate (up to 10% concentration within the air space compared to 3% in the atmosphere) which causes more vigorous neck muscle twitching. This twitching hammers the egg tooth on the beak against the now thinner eggshell. As the embryo shifts in position, the egg tooth cuts a circular path around the large end of the egg, forming a cap that will eventually break loose freeing the embryo from the shell.
Nestling growth and development
At hatching (typically in mid to late April), the new nestling will be covered in wet down that will quickly dry to a whitish fluff (called the natal down). All three embryos will typically hatch within a 3-4 day period and at this stage they are at their most vulnerable to temperature fluctuations. The parents will continue to cover them in the nest cup, maintaining a temperature of 98*F and a relative humidity of 78%.
The newly hatched nestlings will typically eat their first morsels of food within 12 hours, but this is not critical as their internalized yolk sac remnant provides energy for up to 48 hours post-hatch. Early on, the parents will feed the nestlings about every two hours and their first castings will occur by about day 5.
The male parent will ramp up hunting activity to stock the nest with food, providing, on average, just under two pounds of food per day throughout the 45 day period from hatch to fledge. Here is a summary of one year's prey deliveries to the nest, closely mirroring the published data of 70% mammalian prey, 24% avian prey, and 1-3% other.
Between day 5 and 10, the white natal down has been supplemented with the grayish true down, greatly enhancing the nestling's ability to regulate it's body temperature.
The eyes will be fully functional and the egg tooth will fall off by the end of the second week.
Once the wings are long enough, usually soon after day 14, the primary feathers will begin to emerge. This is the only time of a raptor's life that all the feathers will grow at once and they can grow quite quickly too - up to a half-inch per day under ideal conditions.
Between days 25-45, the nestlings will become increasingly active on the nest site, flapping their wings to develop flight muscles, learning to stand, walk, and feed themselves with food supplied by the parents.
They will typically fledge (leave the nest) around 42-45 days (late June).
Fledging and the first few months away from the nest
Once fledged, they will remain in the immediate vicinity of the nest for up to a month.
Their activity level will double within this time, first by simple perch to perch direct flights as their parents continue to provide food.
The parents will gradually move food drop locations further from the nest site until the fledglings are at the hunting grounds -- at first observing their parents in action, then actively participating in the hunt themselves.
The parents will continue to provide food and hunting lessons for up to six months post-fledging but most often the juveniles are booted from the parent's territory and on their own by early fall (August or September, bringing us full circle).
Anndddd....that's a wrap! I hope you've enjoyed the series and I hope to see everyone again for the 2017 season in August! In the meantime, please do stop by the Cornell web cam site as that's where we'll be from now until July!
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Gloves are pretty self-explanatory and we won't spend a ton of time on them. They're sold in singles (left or right), half-length or full-length, insulated or not, several thicknesses, and all the usual hand sizes. They're most often made from elk, deer, or cowhide. What I do want to focus on regarding gloves is shown in the picture below. See that D ring ? That's for tying your bird off so it doesn't escape. Use this EVERY SINGLE TIME you're out with the bird and it's not okay if she takes off.
Laziness gets the best of us all and the tendency is to wrap the leash a few turns around your ring and pinky finger, calling it good. I mean, you're holding on, right? Well, I can guarantee you WILL let go when she spooks and has all 8 talons buried in your face. Sooner or later, it will happen to you so get in the habit of clipping in. Every time.
Now she's loose, with her legs tied together by the swivel and trailing a three foot leash behind her. This is a death sentence, and a pretty gruesome one at that.
Traditionally (and still a valid option) you'd tie the leash off to the D ring with a falconer's knot. Better yet is a clip system as shown below.
On the left is a commercial French style clip and on the right is a standard carabiner-style clip.
These clips make it easy enough that there's no excuse for you to fail to have the hawk clipped in when she's not actively flying. Clip in every time!.
This clip is what those pin holes in the flying jesses mentioned in Part 1 are for. They're small enough openings that they do not snag on branches but are just big enough to accommodate the clip. In this scenario, her legs are not tied together by a swivel with flight jesses, but it sure saves you from the chase you'd have if she took off with a full crop on the way back to the car!
With a leashed bird, clipping in to the D ring is absolutely imperative. Do it every time! Regardless of the leash system you're using, clip into the BOTTOM ring of the swivel. This gives you a solid anchor point yet still allows the swivel to do it's thing and keep the jesses from tangling.
While not technically "furniture", the creance (training long-line) is tied to the jesses (never a swivel) the same way -- with a falconer' knot. The creance is most likely to fail at the attachment point and if it's tied to a swivel we now have a loose bird with her legs tied together. Not good. If it's tied directly to the jesses, she may be loose but at least she can survive!
Bells and Bewits.
Bells are a great help in locating an out-of-sight bird in the field. Pakistani style bells are the most popular. They're sold in pairs, with one a slightly higher tone than the other. This theoretically aids in sound transmission over distance but I find two bells to be overkill and assign one tone per bird so I can tell who's who and who's where even if I can't see them. (Guess which two bells are the used ones in this picture!)
Those funny little leather strips on the left of the above picture are called Bewits. They're essentially miniature removable Aylmeri anklets for attaching bells, transmitters, I.D. tags, etc. on a raptor's leg above the main anklet. Here's how they work:
Feed the pointed end through the loop on the bell
Then pass the pointed end through the small hole closest to the button end of the bewit
When tightened, it firmly incorporates the object (bell) yet at the same time prevents the object (bell) from contacting the leg itself. This is important not only it terms of preventing rubbing, but also frostbite -- metal gets really cold in the winter and can freeze skin on contact.
Next, wrap the bewit around the leg and feed the button through the slit. Presto! It's attached!
The downsides of using the bewit for attachment: (a) bulk - weights adds up fast with things on both legs and (b) they're easily undone by the bird and you'll spend a lot of time searching for your $250 transmitter(s) in the brush.
An alternative is to use small zip ties to attach the bell (and transmitter) to the main anklets. Not super stylish, but lightweight and fast.
Keep in mind that you'll want to zip tie in to one arm only if you're using true Aylmeri anklets. If you zip tie both arms, you're effectively defeating the purpose of using true Aylmeri anklets in the first place!
Transmitters
We've already seen above how we'll attach a transmitter using the leg mount method and here's an in-the-field view of that (using a true bewit, before she learned to unhook them):
The two other common transmitter attachment mechanisms are back pack (Marshall Track Pack) and tail mount. Let's look at the back pack first.
Most of us have seen that transmitter magically floating on a raptors back like so:
The backpack is basically a plastic plate that's about 3/4" x 1-1/2". It's permanently attached to the bird with a piece of teflon tubing. With the plate held along the back, the teflon tubing loops over the head, crosses in the front, and is fed under the wings to the back, where it's crimped in place with a little brass ring. The bird preens the tubing under the feathers and the plate rides on the back immediately between the wings.
The spring arms seen attached to the back of the transmitter above fit through, and catch on, a hole in the top of the backplate like so (this is how you take the transmitter on and off while leaving the backpack on the bird):
Here is a short video showing track pack installation on a raptor:
The tail mount attaches in much the same way (using the same spring arms on the transmitter side) except the loop the spring arms slip through is much smaller and is crimped onto a tail feather as seen in this video:
The tail mount is my least favorite as the transmitter is a (relatively) large weight on that particular tail feather and pulling the feather out in the brush is a real possibility.
Hoods
The hood is the last piece of furniture we'll look at, and the one I'm probably least qualified to discuss at length so we'll keep this pretty basic. The main function of the hood is to keep the bird calm. Vision is the diurnal raptor's primary sense and no sight = no stress.
Fit is, of course, very important and hoods come in about 40-50 different sizes. They're measured in terms of the greatest distance across the head (the eyes) when looking down at the bird from above. In the U.S. / English system, this means size 000 (sharpie) to 00 (kestrel) on up t o 24 (large red tail), then up to 39 for the largest eagles. In the metric system, this translates as size 35mm (kestrels) up to 66mm (ferugies), then on to 80mm for the eagles. Confused yet? Here's a chart showing the differing measuring systems.
There's some trial and error in finding the proper fit and some hood styles even have adjustable chin straps to fine tune the hood to the individual bird.
Having said that, there are many styles of hood with the Arabian (solid back), Pakistani (sometimes solid back), and Dutch (inverted "V" closure in the back) being most popular. Dutch style hoods are, in my experience, the most common style in the U.S. The Dutch (and Arabian) hoods are glued or stitched using forming blocks called Mollen blocks. We'll talk mostly about Dutch style hoods for the remainder of this, but here's a good explanation of some of the other styles if you're interested. Well-made hoods are a fine art and a number of falconers have become well known worldwide for their craftsmanship.
Here we see two open Dutch hoods, size 0 (kestrel) on the left and size 24 (red tail) on the right. Note that on each side is one strap (called a brace) with a knot and one without.
Open DRAWS the braces (closes them) by pulling on the knots and one STRIKES the braces (opens them) by pulling on the braces without the knots. How do you do that one handed? You use your free hand for one side and your teeth for the other --- you really do need to like the people you share hoods with!
Here we see both hoods in the closed position
Frontal view of the beak opening. Fine tuning can be accomplished here by trimming or curling the leather on the sides of this triangle. We can also see the top knot well in this photo - more that just decoration, this serves as a "handle" to guide the hood on and off the bird's head.
There we go! That rounds out this series on Furniture! Thanks for seeing it through to the end, so to speak! :)
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By way of quick review, we've installed either modified or true Aylmeri anklets, jesses, leash extender, and swivel and now we'll introduce the leash, which serves as the link between the swivel and the perch ring.
In it's most traditional form, the leash is simply a length of leather, with either a slit or a button at the swivel end:
Leather is probably the weakest of the leash materials in common use and a falconer's knot in a leather leash is a bit bulky. As a result, most falconers have moved on to other materials.
Braided nylon leashes are by far the most commonly used in modern falconry. Nylon is very strong, impervious to water, and easy to manufacture. (As I mentioned last week, they're also very abrasive by nature and snag on everything. As such, they're my least favorite material).
In it's most basic form, a nylon leash is simply a length of braided cord with a loop at one end:
This loop is attached to the swivel ring with a Girth hitch:
Nylon leashes can also be be made or purchased with integral swivels (pink leash), sometimes even with a built-in leash extender too (black leash on top):
All leashes of this style are attached to the perch ring with a falconer's knot. We'll walk through how to tie this knot is a minute, but WHERE we tie this knot along the leash is critically important - the length of the leash between the swivel and the knot should not be longer than the length from the anklets to the swivel and the total length of the system should not be more than the overall height of the bird. Long leash = broken leg. As we can see in this radiograph, a leash tied too long allows a "running start" to a bate and a tibiotarsal fracture is the usual result:
Here are two leash systems, one for a kestrel/merlin sized raptor and one for a red-tail sized raptor. The appropriate knot location is marked with tape on each:
Enter: the falconer's knot. Learning how to tie this bugger is usually one of the earliest skills a new apprentice learns and, for some reason, gives many people fits. It is basically just a slip knot - I think having to learn to tie it one-handed is what throws newbies for a loop. (Remember, your bird is usually sitting on your non-dominant hand so many things a falconer is tasked with are accomplished one-handed.)
Here we go! With the bird on your non-dominant fist, feed the leash OVERHAND through the perch ring (bird side is on TOP, leash tail is on the BOTTOM).
Grip that bottom leash tail between your index and middle fingers:
Your thumb goes OVER the upper bird-side length:
Through the gap between the two lengths and UNDER the tail-side length:
Catching that tail-side length with your thumb, pivot your wrist while allowing 2-3" of tail to feed through your index-middle finger:
Bring your index finger over the top of the whole mess to meet your thumb, creating a loop around your thumb:
Pull the tail through the loop ( ie., slide that loop off your thumb towards your index finger):
Pull the tail through that thumb loop and there's your knot !:
For additional safety, feed the tail back through the loop:
It's much easier to visualize with a video:
Okay, so your bird has learned to untie this knot (don't laugh - two of our four birds can untie any knot in under 5 minutes). Now what?
There are a couple knot-less leash designs and we're going to have to go with one of those from here on out.
The older of the two I'm going to describe is the Fox loop leash , named after the author and biologist Nick Fox, who's Understanding the Bird of Prey should already be on every falconer's bookshelf. It'a an ingenious solution to the bird-that-can-untie-knots problem, but is not necessarily intuitive to use (Apprentices that have falconer's knot anxiety tend to go into a full blown panic attack when they first see one).
Let's walk through it.
As you can see, it has a standard slit/loop at the tail end and a second in-line loop at the swivel end (also note that it's non-adjustable for length -- you have to buy (or make) the correct size):
Feed the leash through the swivel ring to the top knot:
Feed the tail through the perch ring
Now the tricky part: feed the tail BACK THROUGH THE SWIVEL RING so that both lengths go through the swivel
Slip the tail loop OVER the top knot/button
And slide the tail back through the swivel ring (now you can see we have a Girth hitch at the perch ring)
Fold the button over the swivel ring and through the in-line loop at the button end (not critical, but good to do for safety)
Untying: Unhook the button loop and start feeding the tail back up towards the swivel ring
Feed it back THROUGH the swivel ring and over the top knot/button
Back over the button
Again, here's the video:
The final leash system, and my favorite, I mentioned last week: Jim Coughlin's Bullet Jess System. This leash / jess combo uses strong braided nylon cord sheathed in vinyl casing. It's very strong, has a very smooth surface, and maintains it's shape so that it doesn't catch or wrap around objects. The ends have an Aluminum toggle that just fits through the brass grommet. They can't be used with birds that bite at the leash or jesses (beak chipping will occur) but most adult birds will do just fine with this system. It's also much, much faster than the Fox loop leash for those birds who can untie knots.
The jess combo showing the toggles at the anklet end and the loop for the swivel at the other end (note the set screw):
Assembled with a swivel, it looks like this:
Simply loosen the set screw, feed some cord to the toggle, and slip the toggle through the anklet grommet (or perch ring grommet), snug up the toggle, and re-tighten the set screw. They're super-fast.
Here's the video (using the jess for demonstration purposes but the concept is the same for both the perch and bird ends):
Whew! Another long one ! Sorry for the brain freeze, but paying close attention to these little details is important for our raptor's health and comfort. I think we'll finish up with tethering and the remaining furniture next week. For now, a few birds to enjoy:
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The anklets
The anklets serve as attachment points for the jesses. They're worn a majority of the time and, because they serve to transfer the bating force directly to the legs, a fair amount of thought (not to mention regulation) has gone into their development.
First off: materials. While synthetic materials like biothane are in vogue in some circles, the majority of anklets will be leather - and a very specific leather at that. Kangaroo is the preferred source (yep! the Australian ones with the pouches) because it is very thin, very strong, tear resistant, and has minimal stretch. One can buy half or whole Kangaroo hides in three standard thicknesses suitable for any sized raptor save for eagles (for whom cowhide is commonly used). Further, most commercially available leather is tanned using Chromium salts -- great for water resistance but highly toxic and not at all suitable for falconry. The kangaroo leather sold specifically for falconry is vegetable or bark-tanned and usually not dyed.
A half kangaroo hide, medium weight, suitable for red tail sized raptors. This may be a lifetime supply for a single bird.
Necessary tools: a straight edge, a marker, a sharp blade, and a leather punch
Anklets come (by law in the U.S.) in two basic flavors: Modified Aylmeri and True Aylmeri, so named after the design by Major Guy Aylmeri, a Brittish falconer stationed in Anglo-Egyptian Sudan in the early 1900s.
The Modified Aylmeri anklet uses modern brass grommets and are by far the most common design in use. The brass grommet permanently attaches the anklet to the bird's leg and you'll need a separate grommet setter (as you can see, really a modified Vise-Grip pliers) for each grommet size in use -- 1/4" and 5/16" are by far the most common sizes with 11/64" used for very small falcons like American Kestrels.
The anklet is sized to be tall enough to distribute forces from a bate but not so tall as to trap debris against the leg skin -- 1 to 1.5 leg-widths tall is about right -- and just snug enough to rotate freely when new (they will stretch a little).
I like to set the grommet seat in the first hole and use it to measure length (note the imprint marking the location of the second hole):
Also note the cuts along the top and bottom edges on both the new and used anklets -- this allows the edges to roll over, creating a smooth, rounded edge that does not cause irritation:
Finally, lightly oil with non-toxic oil prior to application (I like olive oil for this). The anklet on the right has been oiled, darkening the leather.
True Aylmeri anklets do NOT use grommets and are, as a result, removable without cutting the anklet. Here is a slightly over-sized pair I keep in my hawking bag for emergencies:
The two outer holes mate up and are analogous to the grommet hole while the inner hole + notch are spaced to fit the hawk's leg like so:
This way the anklet does not over-tighten with bating - the notch maintains spacing.
Jesses:
Jesses also come in two flavors: Field (with no hole or a very small hole at the end)and Mews (with a slit large enough to feed a swivel through)
The genius of the Aylmeri system lies in the jess design. Prior to Guy Aylmeri's invention, the anklet-jess system was often one piece and they often either broke or over-tightened.
Here are the Kangaroo leather Aylmeri flight jesses our HAHA's have used for four years now:
The key is the knot on the left that acts as a stopper to keep the jess in place. (more on the pin hole on the right later).
Here's how to make them:
Cut to length, square at one end and sharply tapered at the other. Fold the square end over 3-4 times and punch a hole through all 4 layers:
Keep the holes lined up and feed the sharp end through the holes:
pull tight and boom! you're done!
Recently, braided nylon jesses have become popular -- they're inexpensive and super strong but they're not my favorite because they're abrasive and prone to snagging on every little thing.
Note the much larger slits at the end compared to the field jesses above.
Finally, a new system uses a toggle button and a length of strong nylon cord inside a flexible vinyl sheath. These are Jim Coughlin's bullet jesses and are a favorite of mine. The button end toggles into and out of the anklet hole and the loop end attaches to the swivel. The set screw keeps them tight and the vinyl sheath maintains it's shape -- ie. it does not tangle or wrap around obstacles.
Swivels
A swivel is also a practical (and legal) requirement , serving to keep the jesses from twisting and tangling as the bird moves about. Here are a variety of swivels, sized for kestrels up to eagles with the middle Sampo style being the most popular (the stem end goes towards the bird and the barrel end towards the leash!)
Here there is a little overlap in describing the parts of the system and we need to introduce something new: the leash extender.
See, we want the swivel to be far enough down the line that it doesn't contact the tail feathers but just making the jesses longer doesn't work.
Think of the whole system as a "Y" with the jesses making up the "arms" and the leash representing the "stem". The swivel is where they meet. If the jesses (arms) are too long the bird will tangle up in them and injure herself. Jesses shouldn't be longer than the bird's tibiotarsus -- about 3" for a kestrel or merlin and no more than 6-7" for a red tail.
Enter the leash extender -- a 3" to 5" length of leash material with loops at both ends. One end attaches to the jesses and the other to the swivel, moving the swivel 3-5" further down the "stem" without making the "arms" of the "Y" longer.
Installed, they look like this: (kestrel set up on top, red tail on bottom)
Putting all that together might not be intuitive, so let's break it down.
--Attach the anklets (I prefer smooth side towards the leg)
--With bird facing you and the grommet pointed towards the rear, feed the jesses from outside to inside through the anklet hole so that the jess knot is on the outside and the ends of the jesses are coming between the bird's legs towards you
--From here feed both jesses through either the leash extender or swivel (remember, stem side towards the bird!):
--Now open the slits in the jesses and feed the swivel / leash extender through the slits in BOTH jesses (this is why the slits are as long as then are):
--Pull tight (Here we can see why those little tails are there on the jesses / leash extender. The system cinches down really tightly over time and those tails are invaluable in loosening things up again.)
--Loop the leash through the other ring of the swivel (the barrel end).
In taking it apart (as in when you switch to field jesses), you can feed the whole leash/swivel/extender system through the jess slits in one swoop:
Leashes are, at their most basic, a length of leather or braided nylon with a slit (leather) or loop (nylon) at one end that attaches to the swivel as above.
This is becoming long enough already, so let's save a discussion of leashes for next time and wrap this up today by looking at the Aylmeri and Bullet jess systems in actual use.
Aylmeri field jesses with bells attached
Mews Bullet jesses (and leash) -- note NEW anklets in image #1, properly rolled anklets in image #2, leash toggle with ring tab grommet in image #3
Nylon jesses and leash extender
Leather jesses and leash extender, nylon leash
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Up until fairly recently , there was quite a bit of "which came first, the chicken or the egg?" debate about feathers:
Did dinosaurs have feathers? (yes)
Are birds living dinosaurs? (yes)
Who else has the genes for feather production? (pretty much everyone - including humans)
Recent fossil finds, especially in China, show feather prevalence many millions of years before birds took to the air and DNA studies have shown that feather production is genetically well preserved across many non-avian genera (including us). This genetic prevalence across the animal kingdom supports the notion that the genetic basis for feather growth pre-dates birds (and even dinosaurs). So, while we all have the genes, we don't seem to have the on-off switches - leaving modern birds the only ones capable of growing actual feathers.
As many of you will recall from the following chart, feathers (15%) are a larger portion of a bird's weight than the skeleton (11%). Growing them initially, and replacing them annually, represents an enormous energy commitment!
Raptor Composition by weight:
- 15% Feathers
- 11% Bone
- 17% Breast muscle
- 10% skin
- 10% Fat
- 10% Leg muscle
- 9% Wing muscle
- 18% Combined Organs
The number of individual vaned feathers varies by species - from a low of around 1,000 for hummingbirds to as many as 25,000 for large waterfowl like swans (most raptors fall in the 7,000-10,000 feather range). Regardless, each individual feather grows in the same way: as a helix, or spiral, from a temporary keratin sheath. As the feather elongates, new barbs are laid down onto the main vane (rachus) by a germinal collar. As the feather reaches full length, the germinal collar lays down the solid quill (calamus). For the long flight feathers, this process takes around 6-10 weeks.
Here is an illustration of this growth from Thor Hanson's excellent book Feathers :
And here are a few photos of the new feather emerging from the temporary sheath as it grows:
In this way, subsequent feathers are continuous with their predecessors - the new feather pushes the old one out as it grows in a continuous string. This also explains why, if a mature feather is traumatically pulled from it's soft tissue sheath, it may not regrow -- the feather's artery and germinal collar may be too damaged to produce new keratin.
Alternately, a damage feather follicle may produce a defective feather, either just once or permanently.
A good example of transient damage is the presence of "stress marks" or "hunger traces". These weak spots along the feather shaft are the result of a nutritional deficiency during feather growth that effect the current feather(s) but not necessarily future ones.
More permanent defects can sometimes be caused by a West Nile virus infection during feather growth - these feathers will often slough at the keratin sheath with replacements in subsequent years bearing a defect at that stage of growth (as in Stanley the Hellgate Osprey's wonky flight feather).
While the growth of each individual feather is the same, the pattern of growth is very different for adults as compared to hatchlings.
Hatchlings:
The first feather growth (natal down) actually occurs while the embryo is still developing within the egg. This whitish fluff dries quickly upon hatching and serves as the hatchling's initial insulation. This is quickly (around day 10) supplemented with (but not replaced by) the grayish true down. Once the legs and wings have grown long enough to support feather development, the vaned feathers appear -- pushing out the natal down feathers as described above. This is the only time in a bird's life she'll grow all her feathers at once. By 6-8 weeks of age, growth is complete (full summed) and the calamus is solid (hard penned). For most raptors, this first set of feathers is somewhat longer (by 1/3-1/2" apiece) than the adult feathers will be and are usually dullish browns on top and mottled whites underneath, thought to help camouflage these inexperienced youngsters - both from predators (above) as well as prey(below).
Adult molting
Adult raptors molt once a year, usually starting in June and finishing in September or October. Three things seem to be necessary to initiate the molt, all of which can be manipulated to start the molt early or even, as is often the case with demonstration birds, reverse molt:
- adequate body condition - usually 10-15% above ideal flying weight (remember, this is an energy-intensive process)
- moderating temperatures - losing down=losing insulation so warmer temps are part of the equation
- increasing daylight - this seems to be the primary trigger for initiating the molt (around 15 daylight hours)
Adults typically do not replace 100% of their flight feathers in any given year -- it is usually not until a raptor's 3rd or 4th year that she has a complete set of adult primary feathers. Interestingly, this trait allows some degree of "aging" a raptor between the full juvenile and full adult plumages in those first few years of life. Jerry Ligouri has a nice pictorial at Hawk Watch International using this method to age Golden Eagles.
Here is a motly looking Dora, I think at her second molt, showing a mix of juvenile, adult, and emerging adult primaries:
Bird nerdiness: Kestrels will actually undergo a partial molt around 6 months of age (November-December) and can look very similar to adults even to experienced birders.
Adult raptors replace their primary feathers a couple at a time, so as to be able to continue flying and hunting in the interim. The next one will not start until the first one is 2/3 grown.
There is supposedly a pattern to how they replace the primaries but I've never seen any individual bird actually follow the "rule" we all had to memorize. Here is said pattern, in case your bird can read the textbook:
- Body feathers -- fairly random, about a quarter to a third at a time
- Secondary feathers -- start in the middle and progress to both ends
- Tail feathers -- start in the center and progress outward
- Primary flight feathers (falcons) -- start and #4 and progress in both directions
- Primary flight feathers (hawks) -- start at #1 (body side) and progress outward
note the emerging red tail feathers as well as reddish body feathers:
Anyhow, after a couple molts one ha quite a few feathers lying about (for imping, of course):
You gotta be quick though as they LOVE to play with molted feathers:
here is a comparison of Harris' Hawk tail and wing feathers, with the juvenile pattern on the left and adult on the right:
Finally, since we are talking about plumage afterall, here are a series of juvenile and adult hawks:
Red Tail, juvenile, second year, 10+ years:
Harris' Hawks
GHO
Goshawk:
and Prairie Falcon (juvie right)
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In the coming weeks I intend to circle back around to a couple of equipment posts as well as continuing with the Owl's training but for today I'm looking back a few years to when all our hawks were babies.
And since I mentioned Helen MacDonald and her Goshawk, here are a couple photos of a friend's Goshawk, first in her juvenile year, then in her second year:
Except for working with Cedric the GHO, it appears the 2016 season is now officially in the books!
Looking back, here are some of our favorite images and videos from the year.
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She continues to do well on pheasants and has even caught a few chukars this year! Her behavior is starting to change with the season now, with less aggression toward prey and more interest in soaring and wandering.
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Most years we'll only print a few for ourselves and close friends but this year we've gotten the green light from Fish & Game to publish with 100% of the proceeds going to our local wildlife rehab center.
The Wildlife Rehab Center of Northern Utah (WRCNU) does great work, taking in and caring for 2,500 wild animals a year. You can learn more about their work by viewing their website here.
If you or anyone you know is in need of a unique raptor-centric calendar, we'll donate 100% of every order to WRCNU! You can preview and order a copy of the calendar from our publisher here . (Bonus: I believe the publisher is offering a coupon code for 25% off this week: enter 6LZFHB4T at checkout).
Like I said, you can preview the whole calendar at the above link, but this is a photography blog after all, so here are the images we've chosen:
Cover
January
February
March
April
May
June
July
August
September
October
November
December
All images are high resolution digital files printed on heavy card stock - the publisher really does do a nice job on these. Hope you enjoy and Happy New Year!
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Speaking of stinky little buggers, Cedric is coming right along -- glacially slow in hawk-time but somewhere around warp-8 in owl-time. Pro tip: owls don't offer running commentary about your choice of T.V. show like HAHAs do.
Lily continues to do well on pheasants - provided we can get a second flush. She's still struggling with rabbits, but the new snow may help - dry ground late in the year is tough sledding for a hawk on the learning curve.
I posted the following series of screen caps on FB this week and I'll repeat them here as they show quite well how hawks like to go about catching pheasants. As you can see, a hawk has almost no chance catching up to a pheasant in a straight tail chase:
But, if you can re-flush the pheasant, they'll get it almost every time:
Then it's dinner time!
Here are the source videos:
Merry Christmas everyone!
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The Feds allow falconers to take both adult and juvenile GHOs from the wild, but the concept of trying to train an adult GHO for falconry is basically too insane even to contemplate. Thus, it's been mostly a matter of waiting for the right circumstance to present itself....
Here now comes a cute little juvie male GHO falling right into our laps:
This is Cedric (after Cedric Diggory, in keeping with our theme) -- all 1030 grams of him. He's quite small for a GHO - a big female will outweigh him by nearly a factor of two - and thus far seems to break all the GHO rules by being a sweetheart to work with. He's taken right to the glove, rarely bates, eats well by hand and, most importantly, seems disinclined to either bite or foot.
Training him to take game might be a slow process, but we're off to a great start! Note here the anklets padded with rabbit fur - GHO's are booted like Ferrugies and Eagles and the padded anklets serve two purposes: protecting the delicate leg feathers from irritation and camouflaging the anklets to minimize picking.
The happy camper:
Lily continues to do well (except for catching jacks) and has about another 6-8 weeks left in her season:
Lily's been out and about though, doing well on pheasants, less so on rabbits. She's chasing them very well, but not finishing hard enough to actually catch them currently.
In this first video, we see her missing both a pheasant and two rabbits. We also see her get frustrated and take off a half mile up the valley. This is an interesting difference between the HAHAs and the RTHAs -- they HAHAs are game to get back on the horse and keep trying but the RTHA starts pouting after a couple misses and lets her frustration get the best of her.
In this second video, we see Lily being a little more successful. Hawks tend to want to strike at a pheasant either right on the flush or upon landing. If you can reflush the pheasant after a miss, they'll get it 90% of the time. The big trick in the sage: pheasants prefer to run rather than fly when they know a hawk is about and they're really good at slipping away on foot without being seen. Also note how, early in the hunt, she's game to jump right back up and keep hunting.
She's also getting a bit more creative in her choice of dining area -- it's getting harder to get good photos with her wedged under the sage.
The sunsets are a bit of a consolation prize for those unsuccessful outings -- and icing on the cake for the successful ones!
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I have one more video of the HAHAs hunting that I'll try to get finished for next week, but the girls are done with their season now and enjoying their heated mew.
Lily the red tail really seems to be enjoying the colder weather though -- if anything it seems to have sharpened her concentration. She's still doing well on pheasants and we're working on introducing her to ducks and rabbits.
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Lily is just coming into her element now though and is raring to go!
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We do have all three birds back in the air though - and all three are catching game now. As we've discussed before, their time on the ground is their most vulnerable and the falconer has two jobs here: help wrangle the prey if need be and protect them from other predators while they eat.
Let's start with Lily's first pheasant of the year as I know this is what many of you have been waiting for all along....
The HAHAs have a little game too -- they just usually wind up upside down or inside out when it's all over....
Luckily, no one was injured but it did consume at least one whole day so far. Dora didn't enjoy the ride in the tow truck either if you were wondering!
Dora hasn't missed a beat hunting solo, catching six rabbits this week all by herself. Tonks is healing well and is off antibiotics now. She should be good to get back out into the field late next week.
Lily is coming right along and we should have her out after pheasants tomorrow or Sunday...
I didn't get time to download any of the videos or photos this week due to the wrecking the falcon mobile , so here we go to the archives:
Hopefully we'll be back to full strength by next week!
this was their first bunny ever:
Full and happy post hunt:
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I've managed to forget just about every piece of gear at least once -- except for the birds. I haven't taken off and left the birds at home--- yet....
Their boxes are big enough that I usually notice if they're not in the car yet:
Here's my hawking bag though. Lots of little things that are easy to misplace:
Aside from the cameras and telemetry, most of this stuff if either for first aid, taking care of game caught, or recovering a wayward bird.
That's usually enough to get us back to the car where the real first aid kit lives:
Good thing too because, without a hint of irony, Tonks decided to follow up our post about medical issues by lacerating her foot. She's got 3-4 stitches now, some antibiotics, and a two week vacation on tap.
There are actually three separate cuts there, one sutured and two closed with tissue glue.
Dora will be going it solo for a bit, and we hope to turn Lily loose after pheasants in the next day or two!
For now, here are some new pictures and videos from the past couple weeks:
We've got three birds going in three different directions now and we'll keep you up to date on everyone's progress!
]]>Today I wanted to talk a little bit about medical issues and injuries. As a veterinarian, this is a subject that is right in my wheelhouse. Unfortunately, my experience is that it's something many new falconers are ill-prepared to address.
The truth of the matter: being a raptor is a hard living and the only ones not getting hurt are the ones not doing any hunting. Remember, raptor mortality in the wild is 80-90% and there is a narrow window to catching a minor problem before it becomes a major one.
We won't be able to comprehensively address this very broad subject here, but let's hit on the most common issues, grouped by problems at home and problems in the field. (For those who like medical reading, a more comprehensive discussion can be found here.)
Problems at home
Like most other animals, proper husbandry can prevent nearly all of these issues:
Aspergillosis
Caused by the fungus Aspergillis fumagates, the most common form is infection of the respiratory system. Untreated, it is usually fatal within 10 days and arctic species like Gyrfalcons, Goshawks, and Snowy Owls seem to be the most susceptible. While ubiquitous in the environment, primary exposure is via moist organic matter in the raptor's environment and prevention is as simple as keeping the mews clean and dry.
Bumblefoot
Bumblefoot is a collective term for bacterial infections of the foot secondary to either inadequate perches or small defects in the skin of the foot that then seal over, trapping the bacteria beneath the surface. Raptors are very good at healing skin lacerations but have poor blood supply (and thus poor immune response) to their distal legs and feet. Further complicating this condition is the fact that purulent material (pus) in raptors does not occur in liquid form but rather rubbery nodules that have to be surgically removed. Prevention is again they key -- utilizing appropriate perch surfaces and treating minor foot injuries aggressively. Surgery, antibiotics, and even orthotic shoes are necessary to correct advanced cases.
Here is a Prairie falcon that fractured her left tibiotarsus and subsequently developed bumblefoot of the right foot because she was supporting her weight entirely on the right side for a week prior to presenting at the vet. Note the swelling of the right foot and secondary sloughing of the dorsal skin.
Frounce
Frounce is a highly contagious fungal infection cause by Trichomonas gallinae. It affects the mouth and the throat, forming white or yellow plaques that often need to be surgically removed. Pigeons commonly carry Trichomonas in their upper GI tract and are thought to be the main source of infection.
Prevention: don't feed pigeon heads or GI tracts.
Sour Crop
Sour crop is simply a bacterial infection of the raptor's crop, often caused by damage to the crop lining or sub-par food sources. The crop does not have the antibacterial properties of the stomach (stomach acid) and the longer food sits in the crop, the more time bacteria has to replicate and cause problems. Treatment often involves flushing out the offending material and it's attendant bacteria, often followed by antibiotics. Prevent this by...wait for it(!)..... only feeding high quality food and not over-feeding.
West Nile Virus(WNV)
One of the few avian problems that's been widely publicized, WNV is invasive to the U.S. and attacks a bird's nervous system, respiratory system, and spleen. Raptors that survive an infection often have lingering neurological and respiratory problems that end their hunting careers.
Vaccination is quite effective and I recommend all falconry birds be vaccinated with the Merial Recombitek equine WNV vaccine.
Picture Break!!!
Problems in the Field
This category is largely comprised of injuries that occur while hunting. Flying is a dangerous way to make a living - some of these can be avoided and some cannot. If and when any of these problems do occur, the key is to keep the bird calm, cast her so she doesn't make the injury worse, clean the wound if applicable, and seek medical attention promptly.
Electrocution
This is the biggie - one of the most common causes of mortality in wild hawks. It can be prevented in falconry birds by simply avoiding fields with utility poles that are not of bird-safe design. Utility companies have gone to great lengths to correct this problem but there are still dangerous lines out there.
( For those of you with a couple hours to burn, here's the standard best practice construction guideline that utility companies use for both new construction and retrofits of existing lines. If you can make it through the first hour, there are pictures in the second half of the paper, I promise!)
Here is an electrocuted Prairie falcon image from Montana Fish & Parks. The falcon's foot is still embedded in the pigeon.
Fences and blunt impact trauma
Blunt impacts are less of a problem for falconry raptors than wild ones - falconry raptors usually impact a tree chasing squirrels or get clothes-lined by a branch while riding a jackrabbit. These can still be fatal though, either by head trauma or cervical fracture.
Fences, particularly barbed wire ones, are a bigger problem as they're very hard to see in flight and are ubiquitous. Fence impacts often result in either clothes-lining as above or impressive lacerations. Choosing fields where you can stay at least 100yds away from fence lines is your best bet in terms of prevention.
Tonks hanging up on a fence (at 2:20). Note how she doesn't try to do anything to make this worse - she waits for help.
Limb fracture
This impact injury can happen at home just as easily as in the field. The following diagram marks the most common fracture locations in hawks (for falcons, add foot and toe fractures as well). Keep calm, cast the bird, and get thee to a vet! Nylons or pantyhose work great for casting a bird in the field and should always be carried in your hawking bag.
This is actually the Prairie falcon used in the bumblefoot example above. This left tibiotarsal fracture is a classic over-weight bird + over-long leash fracture as this is the spot most likely to give when the bird bates.
Same fracture in a Harris' Hawk.
Broken Feathers
Not really an injury per-se, but can affect flight performance. These will be replaced during the molt but repairing these in-season is called imping. Here's a video for those interested: Imping.
Lacerations.
These can look impressive but unless they're located on the foot, they'll heal quickly if kept clean and sutured closed. Again, cast, clean, and seek veterinary care.
Punctures and Bite Wounds
If you're flying a cast of Harris' Hawks, they'll eventually puncture each other grabbing at game. If you're flying a solo hawk, bite wounds from the game animal are most common, especially on the feet. Again, the skin heals quickly but bacteria deep in the wound is the real risk here. Clean as best you can in the field and and seek veterinary care as antibiotics are always indicated for bite wounds to the feet.
Dora's foot a few years ago -- I think from a weasel if memory serves.
This is a Goshawk's foot after being bitten by a gray squirrel. Note the spiral fracture and questionable blood supply to the distal digit. This is not my case and is currently under treatment, final outcome not yet known but amputation is a real possibility here.
Talon Injuries
The talons actually have a bone running through to very near the tip. Sloughing the talon sheath or breaking the talon off expose this bone. If not cared for, one of two things will happen:
a) the bone will recede, even crossing the joint and requiring amputation of the toe.
b) the bone is broken off and the claw will not grow back.
I've seen these mostly in Harris' Hawks (why, I do not know) and Gyrfalcon hybrids.
Here's a Dora talon fracture, also from a few years ago. That white stuff is bone.
The bone is protected with either cyanoacrylate tissue glue or clear nail polish.
This is then covered with heat-shrink tubing to form a lasting bandage
These take six to eight months to heal. Here we are in August, nearly a year later.
This last case was another Harris' Hawk who got her talon bitten off by a jackrabbit. Compare to the photo above and note the bone is missing. This will not regrow.
Healed to the extent it's going to.
I know this was a fairly superficial run-through of a very broad subject. Remember, cast the bird (don't forget your pantyhose!), clean the wound, and get thee to the vet! Modern medicine is really pretty amazing if we can get to things early. Taking a week or two off to allow an injury to heal is a minor blip in a bird's 10-12 year hunting career. Don't risk it! Take the time, make the effort, and you'll be back up and running in a snap.
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Tonks and Dora passed the 50 rabbit mark this week and Lily is ready to be flying outside now so the season is moving right along.
Here my family themeed photo essay for the week:
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Fall is in peaking here now, many of the trees above 8,000' are shedding their leaves already and the raptor migration is in full swing. These days it's pretty easy to spot 50 red tails and 10-12 prairie falcons no matter which direction one might take out of town.
There are too few bluebird October days like these to sit inside when we could out in the sage with birds in the air...
Since everyone else is on the move this time of year, here's a quick sampling of old and new October on-the-wing photos to tide us over until next week!
break time!
We had a little bit of a close call yesterday while I was playing hooky -- Dora bound to a rabbit a full three feet down in a badger hole. I'm thankful for long arms as I could just reach her buried up to my elbow.....
Annnnddddd..... a couple of recent videos for those so inclined:
Lily will in all likelihood be flying outdoors by next week and hunting by the week after so if you're getting bored with the HAHAs, stay tuned...
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In the wild, the vast majority of a hawk's diet consists of small mammals (68%) or small birds (17%). These are usually spotted from a high perch or soar and caught by more or less dropping straight down onto, say, a rodent in a the grass. A falconry hawk is going to be expected to go after much bigger game on a regular basis - jackrabbits, pheasants, ducks and geese, etc. that may be three to four times the weight of the hawk. Success requires a bit more strategic thinking, some of which is learned in training but most of which is learned by trial and error in the field. Today, we'll (hopefully) see how that works for a few different prey species.
Upland game birds like pheasants and grouse
These are very fast birds in level flight -- too fast for even falcons to overtake in a tail chase and success is going to come either at the beginning or the end of their escape flight. The Harris' Hawks have missed three pheasants so far this year striking at them on the ground prior to their taking flight and unfortunately each time the pheasant flew over a mile down the mountain.
The key strategy here is to mark where the pheasant lands after that initial flush. If the pheasant can be re-flushed, the hawk will catch it nearly 100% of the time on that second rise, often in the air.
Waterfowl, primarily ducks
Ducks are just as fast, if not faster than pheasants in a tail chase and they have the added benefit of using water as a distraction. A duck can seemingly disappear in a half-inch of standing water and leave a confused hawk sputtering and wondering what happened. We don't purposely hunt ducks much as there is currently an avian influenza (HPAI) outbreak locally but the concept is very similar to pheasants -- hit them rising or landing, not in mid-flight.
In my personal experience, this is the most common outcome chasing ducks:
Mice and Voles
I consider these to be more of a distraction than an actual game species to go after but voles are apparently the chocolate chip cookies of the hawk world - they absolutely cannot eat just one!
Here the HAHAs snarfed down five voles in about 15 minutes while we were (presumably) hunting rabbits:
Cottontail rabbits
If voles are the chocolate chip cookies of the hawk world, cottontails are a triple shot of Espresso for them. If you ever run across a hawk that seems to be phoning it in, get them on cottontails -- I've yet to see a hawk that gives less than 150% effort in going after these little guys. They (at least the mountain cottontails we have here) are really small, and really, really fast. They're also a burrowing animal and are never more than 10-20 yards from a rabbit hole. Slips are short and fast and hawks quickly learn to lead them a little on the strike. Having more than one person to beat the brush and flush them is very helpful here.
Jackrabbits
Black-tailed and White-tailed jackrabbits will comprise the bulk of the hawking opportunity in the western states and definitely qualify as big game for a hawk. An adult jackrabbit will weigh four to five times more than the hawk and most hawks will experience the bucking bronco ride until they learn where the off switch is.
It's also with jackrabbits that Harris' Hawks, with their cooperative hunting strategies, really come into their own.
Unlike cottontails, jackrabbits typically do not use borrows. Their survival strategy is dependent on a combination of speed and quick turning. They'll usually either abruptly stop to hide under a bush or deliberately slow down a little in an attempt to bait the hawk into committing to a strike. If the hawk takes the bait, the rabbit will abruptly turn 90 or even 180 degrees and speed off, leaving the hawk standing there.
Depending on the thickness of the sagebrush in a given field, the Harris' Hawks have developed three distinct strategies to counter those tendencies.
Thick brush
Here the rabbits will almost always stop to hide within 100 yards. The hawks will follow about ten feet off the ground waiting for the rabbit to stop. Once it does, they'll flare up 30-40 feet and stoop straight down on the rabbit, usually staggered so the second hawk is about two seconds behind the leader.
Two videos showing vertical stoops in thick sage:
Open ground
Here, the rabbit will run long distances (a half mile or more) and will try to bait the hawk in. The hawks have learned this trick and compensate by following much higher - more like 30 feet than 10 feet. Once they have position, the lead hawk will take the bait, usually from a lower angle than the vertical stoop mentioned above. This is more designed to turn the rabbit in the desired direction than a full on kill attempt by the first hawk. The second hawk is ready and waiting - positioned to strike 10-15 feet off the turn and before the rabbit has reached full speed again.
Two videos of open ground tandem strikes:
Corralling
The first two techniques described above are successful approximately 30% of the time --a success rate two to three times better than that of a solo hawk on jacks. In their first couple seasons, the Harris' Hawks would just move on after missing a rabbit but in the last two years they've developed a technique I call "corralling" that enables them another try at these missed rabbits.
Here's how they do it. After the initial miss, each hawk will jump up on top of a sagebrush opposite each other and about 30 yards apart. One hawk will fly 10-15 feet at a time around an imaginary circle while the other one watches. They'll then trade roles while they spiral around, gradually tightening the circle until the rabbit breaks. One is always watching the middle while the other is moving and they'll pick up an extra rabbit a week this way on average.
Here's a video from this week showing them successfully doing this twice.
Also, remember all those pictures I post of them perched on a sage? This is what they're doing -- the pictures are of the watcher focused on the middle while the flyer is tightening the circle.
Squirrels
We don't hunt squirrels here in the west, but in the eastern states gray and fox squirrels are often a primary quarry. I cannot speak from personal experience, but I understand they are hunted primarily by chasing them through the treetops. I will say though that squirrels have very sharp, chisel-like teeth that can slice through leg tendons like butter and even break bones. Indeed, many falconers outfit their hawks with squirrel chaps , to protect the hawk's legs and toes from bites:
Here is a recent photo a falconer sent me of a Goshawk's mangled middle toe following a bite from a gray squirrel. The P2 bone has a spiral fracture from the bite and this toe may well need to be amputated.
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The Harris' Hawks are well into their season now, with 33 rabbits in the freezer. We'll check in with them later, but for now let's continue to fill out some of the behind-the-scenes aspects of falconry we glossed over earlier.
Later on, we'll devote a whole post to the things that are actually attached to the birds but today we'll focus on housing and its associated accessories.
A refresher on the Federal and State-mandated minimums:
-An indoor mew or covered outdoor weathering yard, or both
-One bath pan, at least six inches deep and as wide as the bird is tall
-One swivel and leash suitable for falconry
-One pair of Aylmeri jesses or material to make them
-One perch of suitable design
-One scale accurate to 1.0 to 5.0 grams, dependent on the size of the raptor
Looking at this list, it would be easy to assume one could get into this falconry thing pretty inexpensively. This is true, one could get started for as little as maybe $2,000 -- but it won't stay that way for long!
The first thing we'll discover is that one of everything just isn't practical -- we'll soon have a tackle box full of leashes and swivels, a stack of bath pans, 5-6 perches at $150 each, a scale in every possible location they'd be useful (I think we have six), a glove in every possible location (again, at least six), at least one radio transmitter for each bird (yep! you guessed it - six), a separate mew for each bird, etc.
Before you know it we'll be wanting an outdoor flight chamber and a dedicated hawking car and -poof! The sky's the limit...
Bath pans are pretty straight forward if sized correctly:
But there are nearly unlimited ways to mess up a perch and cause harm to the hawk, so I generally recommend purchasing them, at least initially. I really like this portable model for hawks - it comes with both spikes and feet for indoor and outdoor use:
Here's a scale accurate to 0.5 grams, a tackle box full of goodies, and a pile of gloves:
On to the mews!
The regulations devote two whole pages to required features of a mews. Here's the short version:
-sized so the bird can fly freely (if untethered) or bate (if tethered) without striking the walls, meaning:
-at least six by six feet x six feet for a Merlin, Sharpie, or Kestrel
-at least eight x eight x eight feet for a raptor up to red tail size
-at least 10 x 12 x 12 feet for an eagle
-at least one side has a window constructed with vertical slats or bars , spaced less than the body width of the smallest bird to be kept
-non-abrasive walls that can be disinfected easily
-flooring that can be replaced (or disinfected) as needed as well as providing a suitable substrate for the raptor's feet and talons
Given these parameters, it's usually simpler to build to suit rather than trying to modify a storage shed or some such out building.
Here is a brief photo essay of the construction of our insulated, heated double mew for the Harris' Hawks:
There's the stuff:
And the site:
And a supervisor:
Making the windows:
And the walls:
Framed in:
Roofed:
Insulation and electrical:
Done!
Note the smooth Coroplast walls and sand substrate (perches not positioned for use yet).
A double door entry and work room are strongly encouraged!
The parameters for an outdoor weathering yard are similar, but if you're going to do that you might as well build a flight chamber, right?
This one's 20 x 15 x 12 feet:
Who remembers this old Cornell chat format?
Anyhow, the HAHAs have been busy and we've had our first snow so they've had their heat turned on already this season...
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The Sagebrush Sea, or more formally, the Sagebrush Steppe, is a 250,000-square-mile high-elevation grassland stretching from Alberta Canada to Baja Mexico. It is a land of extremes: too dry for trees to grow, always windy, and with annual temperature variations of 150*F. It is home to more than 400 species of plants and 250 species of animals, including 27 (27!) different raptor species.
This diverse landscape is anchored, and dependent on, just two dominant life forms: its cryptobiotic soil crust and its Sage.
Cryptobiotic Soil
The cryptobiotic soil crust is a living surface layer composed of cyanobacteria (particularly Microcolues sp.), green and brown algae, mosses, lichen, fungi, and bacteria. Together, they form a surface crust that traps moisture, dissuades invasive plant species, and protects the soil underneath from wind and water erosion. Biologically, the crust can remain dormant for many years in dry conditions and reanimate in as little as three minutes when precipitation returns. It also plays a vital role in fixing carbon and nitrogen that all other plants in the ecosystem depend on. Disruption of this crust has been shown to decrease nitrogen availability for sage plants by 80%.
As important as the cryptobiotic crust is, it is extremely fragile and easily disrupted - i.e., don't ever walk on it if at all possible!
Under ideal conditions, a 1-2mm layer can reform in as little as 5-20 years but a mature crust can take 1,000 to 5,000 years to fully regenerate. It's estimated that the Sagebrush Sea has decreased in size by 50% in the past 50 years, primarily due disruption of this crust by oil drilling and livestock grazing. Once the base soil layer is exposed, erosion and invasive plants like cheatgrass take over, making the sea just a little smaller with each insult...
Sagebrush
Sagebrush (Artemisia sp.) is of course the dominant plant on the steppe and is a member of the Sunflower family (Asteraceae). Who knew?
Depending on who you ask, there are between 20 and 30 subspecies of sage with the Big Sage or Great Basin Sage (A. tridentata) predominating. This sage species can range from one foot to 10 feet tall and is unique in that it has both deciduous (seasonal) and evergreen leaves. The deciduous leaves grow in the springtime when water is more abundant to support the growth of flowers and seeds before being shed in the fall. The evergreen leaves then take over and allow the sage plant to grow even through the harsh winter.
The volatile terpenoid compounds that give sage its distinctive odor can serve both as a protectant to dissuade grazers as well as an attractant to draw them in, depending on the time of year. (Great Basin sage produces Coumarin after seed production as an attractant).
Fun fact: Sage plants can sense an increase in volatile compounds from crushed leaves in the air from up to 5 feet away and instantly increase their own production in response to the perceived threat!
So, there be rabbits in there too? Oh, yes!! Both Black-tailed and White-tailed jackrabbits as well as Cottontails in the draws where runoff is common.
It's not all scorpions, rattlesnakes, and Jerusalem crickets!
In fact, rabbits are so ubiquitous in the ecosystem that their trail networks are used by everyone else moving through. These trails are etched, often very deeply, into the soil between cryptobiotic layers. Rabbits will duck off the trail under a sagebrush for aerial protection but they will rarely leave the trail system while on the move. Raptors following a running rabbit in this habitat resemble the helicopter view of a high speed car chase -- left turn, right turn, take the upper fork at the Y, and they quickly learn to gain enough altitude to see the whole trail system rather than following low and behind.
Okay! Time to hunt, right? The girls sure think so!
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Granted, they're a desert species so everyday interactions with large bodies of water are not the norm. They do like to chase ducks though so these things are going to happen from time to time.
Tonks & Dora had their first deep water swim this week and I was torn between laughing at their "Dad! Get it off of me!" facial expressions and concern about the waterproof rating of the $400 worth of radio transmitters that were now underwater.
It took them about 20 minutes to sort the whole thing out and swim to shore. Let's be generous and give them a 5 out of 10 for effectiveness and a 3 out of 10 for style:
They did figure it out on their own though, and after another 20 minutes of drying out were ready to go again. Luckily it was quite warm out too, so no worries about hypothermia. I'm also happy to report that Marshall Scout transmitters are indeed quite waterproof!
Here's the video that accompanies the above images:
So, having mentioned radio telemetry several times now in passing, this might be a good time to flesh the concept out a bit. It's not hyperbole to say that telemetry is really the only significant advancement modern humans have contributed to the sport of falconry, but what a lifesaving advancement it has been! The ability to quickly find a lost bird over both short and long distances has saved many lives, not to mention saving the falconer many gray hairs along the way.
Becoming a proficient radio tracker is as much an art as it is a science - indeed, major manufacturers hold contests with large prizes for both the fastest and most complex transmitter recovery.
Here's the short version:
The bird wears a small transmitter (5-10 grams) with a six-inch antenna attached to an anklet, tail feather, necklace mount, or backpack mount. This transmitter emits a single beep once per second, with a typical battery life of 20 to 30 days. Transmitters that operate at higher frequencies, like the 434 MHz Marshall Scout, have a line-of-sight range of 60 miles or more.
The antenna used in these transmitters is called a short end-fed dipole which will be important later as it means the strongest signal comes from the side of the antenna and the weakest signal comes from either end of the transmitter.
The falconer has a hand-held receiver with a highly directional antenna called a yagi.
In sweeping the receiver around, the signal will be strongest when the yagi antenna is in the same plane as the transmitter's antenna (vertical/vertical or horizontal/horizontal).
Here is the face of the receiver:
The signal strength meter on the right is proportional to distance and the receiver is calibrated so that closing half the distance doubles the signal strength readout.
The range switch on the left functions as an attenuator in blocking out signals that are too strong to get a directional reading:
far = 400 yards to 60 miles away from the transmitter
medium = 40 yards to 400 yards away from the transmitter
near = less than 40 yards away from the transmitter
In practice, we want to use the lowest range setting and the lowest volume we can hear reliably and walk (or drive) in the direction the signal is strongest, stepping down the range switch as we get closer. Using an ear bud headphone is the secret sauce to a quick directional heading!
So why bother with the expense and learning curve with this voodoo?
Long distance recovery
This is the Captain Obvious one. Say your hawk catches a thermal, or your Gyrfalcon is being a Gyrfalcon, or your Prairie falcon is being a Prairie falcon. They're 20 miles away in a matter of less than an hour and you have to catch up (ie., drive there).
During the kite training session we reviewed last week, Caleb's other falcon, a Gyr-Peregrine cross, took off in a straight line north, landing in a field of waist-high grass about 10 miles away. Using telemetry, we were able to recover her without incident in less than 30 minutes.
Off she goes:
Yep:
There she is:
Short distance recovery
Quickly finding your hawk on the ground after it's caught game is equally important as they are most vulnerable on the ground -- you have to get there before the owls and coyotes do. We'll have usually seen them strike at game and know about where they are, but remember that panorama of our favorite field? How easy would it be to zero in on the one sagebrush plant they're huddled under from 100 yards away?
And that's assuming they're just fine and eating away at their fresh kill. What if they were in trouble? Here's the aftermath of Tonks catching a jackrabbit and pulling it into a hole on top of her. We were only about 50 yards away but quickly finding her with the telemetry was the only thing that kept her from suffocating:
Here are two videos using telemetry to find the HAHAs quickly even though they're less than 100 yards away:
Bonus footage! Here's the rest of the HAHA's post-swim hunt from last Sunday:
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Tonks & Dora have been hunting for about two weeks now and have 12 rabbits in the freezer already. Lily is still waiting out the molt - and for the weather to cool a bit. She'll likely be hunting by mid October.
So, where are we going from here? Dunno! That's the thing about doing a blog in real time - I don't know in advance what's going to happen either. Primarily we'll be following the Harris' Hawks , and later Lilly, week to week over the next six months as they progress through the hunting season. We'll also make an effort to incorporate some new falconry info into each week's post. Those first four posts really were the 30,000 foot overview -- there's a whole heap of stuff we glossed right over.
To wit: We have (so far) condensed this into 16 minutes of reading:
This week we'll walk through the process of getting the birds ready to go from the mews to the field, what we actually do while we're in the field, and how we manage to get everyone home again.
They'll go from the mews:
Into their travel boxes, called Giant Hoods, which should be made of Aluminum or Coroplast for easy cleaning:
We've all seen raptors at a demonstration at some point and the ones that were being actively handled were always wearing some sort of gear, referred to as furniture in falconry parlance. I'll do a separate post later specifically on all the equipment we use but for now realize that the furniture they wear in the mews is different from what they wear in the field. Specifically, we need to switch from mews jesses (with slits at one end to attach to the leash) to field jesses (with only a micro hole or no slit at all).
mews jesses on the left, slit-less field jesses on the right:
While we're switching out the jesses, we'll also attach their radio transmitters (with a range of 60 miles) and bells (with a range of about 60 yards) - both of which are invaluable in quickly locating a hawk in the brush:
Into the falcon mobile and off we go to our pre-scouted hunting field! Emphasis here on pre-scouted because what use are we to the hawk if we take her somewhere where there is no game to chase?
Our hunting fields are anywhere from 30 minutes to 90 minutes away, and the hawks somehow know exactly where we're going. They're able to count every turn and uncannily start fidgeting within 5 minutes of arrival regardless of the chosen field.
Once there, we turn on the transmitters and release the birds onto their T-perches - we use extendable painting poles with a perch attached on top:
Riding 15 feet in the air on the T-perches as we walk around gives them an enormous visual advantage - an experiment we did one year revealed they see 80-85% more game on the T-perch compared to riding on the glove.
We usually have some sort of planned route to cover the field, which never, ever works out exactly as planned. (I'm looking at you, Dora!)
The general idea is to produce at least 10-12 flushes (called slips) in a two hour hike. The birds are good for about two hours before tiring and if we can give them a dozen chances they'll catch at least two, and sometimes three, rabbits in that time frame.
On a kill site
When they do catch a rabbit we need to do a couple things:
-Offer protection as the time they spend on the ground is by far the time they are most vulnerable to predators - and predators make a bee-line to a caught rabbit.
-Help subdue and humanely dispatch the rabbit. The birds will do this themselves given enough time but in the wild there is a tendency for the eating to start before the prey has fully expired - something we're definitely not okay with in this setting. How? Well, we can't really shoot it now, can we? We can't use a blade either lest a hawk grab it and ruin her hunting career. We'll use either cervical dislocation or thoracic (chest) compression as the fastest, most humane way to do so.
-Trade off the rabbit. For the first few kills, we'll let a young hawk have her fill to reinforce the catch-reward connection. Long term, however, this is problematic in that she's going to be too heavy to hunt for the next week or so if we let her crop up. We need to get the rabbit away from her while also feeding her a measured portion. The art of the trade-off accomplishes both by simultaneously offering a portion while removing the rabbit from her sight. Remember, raptors are visual creatures - if they're not looking at it, it's not actually happening. Falconer's also happen to be master magicians is this regard. With a pair of Harris' Hawks, we'll simply remove a forelimb for each bird as two forelimbs just happens to be a day's ration.
We'll dress and stow the rabbit while they're eating. For the first rabbit they'll be ready to hunt again in 10 minutes or so. For the second rabbit, will clip them back in to the glove through those pin holes we saw in the field jesses above and head home when they're done eating. Note: rabbit number two nearly always gets caught at the absolute farthest possible distance from the car.
Make sense?
Here are a couple two-rabbit hunts to pull everything together:
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Dora Surveying the valley a few days ago
The Harris' Hawk.
Harris' Hawks (at least the North and Central American sub-species commonly used in falconry) are unique in that they are the only social raptor - they live and hunt in matriarchal groups of 4 to 7 individuals in the wild. This has several important implications to falconry:
-They should be pack-bonded rather than food-bonded to the falconer.
-They are naturally inclined to continue hunting until everyone is fed, ie., they will hunt at a much wider weight range than most raptors will.
-Their social nature often makes them a poor choice for a solo bird. Indeed, many reputable breeders will only sell them to a home where they'll be paired with at least one other Harris' Hawk.
In many ways, training a Harris' Hawk is the inverse of training a wild-caught Red Tail - the Harris' naturally pack-bonds but doesn't know how to hunt while the Red Tail knows how to hunt but needs to bond with the falconer.
If we tried to make a Harris' Hawk go through the same steps we did with the Red Tail last week, we'd ruin her - primarily out of sheer boredom and resentment. First of all, we form a falconer-hunter bond rather than a falconer-food bond right from day one. We never feed a Harris' Hawk off the glove - ever. The glove (or T-perch) is where we look for food, not where we get it. We'll call the bird to the glove/T-perch, walk a few steps, then toss a food tidbit on the ground for her to pounce upon.
Once she's made weight and done this 2-3 times, training at home is over. Quite literally a juvenile Harris' Hawk should be flying at game in the field within 10-12 days of leaving the breeding chamber (compared to 30-40 days for a wild-caught hawk returning to the field). No wasting time with exercises in the yard. Everything she needs to learn happens in the field. Besides, it's not like she's going to leave. As the adage goes: "The only way to lose a Harris' Hawk is to drive home faster than she can follow..."
This is also true when restarting the hunt after the summer molt -- the Red Tail will generally require a refresher course of sorts the first year or two to get the kinks out but the Harris' Hawks are jessed up and turned loose straight into the field as soon as their weight comes down to anything resembling their hunting weight from last year.
Tonks & Dora, 13 days out of the breeding chamber:
It took them about 100 tries over 10 days to catch their first rabbit but nothing we could have done at home would have shortened that learning curve a bit -- in fact, it would have only lengthened it.
The Accipiters
I haven't mentioned much about Accipiters like Goshawks & Cooper's Hawks because, frankly, they're just a great big ball of crazy and numerous books have been written about how they're different from everyone else, especially an imprint Accipiter. However, a brief mention makes sense here as a segue into training true falcons as it allows us to introduce a new piece of equipment: the lure.
Same Goshawk, in year one and two:
With the bigger hawks, the lure functions primarily as an emergency recovery device but with raptors that specialize in avian prey, such as the Accipiters and the true Falcons, the lure becomes a vital tool both for training as well as daily exercise and conditioning.
Quite simply, the lure is just a padded pouch of leather swung on the end of a string. It can be (and should be initially) dressed up to closely resemble targeted quarry like a rabbit, grouse, or starling. It should also initially have a loop to attach food but once the bird knows the game even a glove or hat tied to a string will do.
On the left a rabbit lure with rabbit hide underneath and on the right a starling lure:
The avian prey lure can be swung horizontally, vertically, or in a figure eight pattern making it progressively harder for the bird to catch but care should be taken to mind the following principles:
-Train the bird to strike from upwind if possible (the falcon has a speed advantage going with the wind but less so into the wind, especially on a second pass).
-Train the bird to strike and stand on the lure rather than bop it and land nearby.
-Let the bird have the lure every time she hits it, gradually working on getting her to transfer to food on the glove.
-Fly the lure so that we're training her to chase and strike the lure in accordance with her species' natural tendencies:
for Accipiters, a short vertical lure rotation with the strike at the apex mimics a quick strike from behind and below, hitting on the upswing each time
for Gyrfalcons and Merlins, a long horizontal rotation with a sharp pull up at the end mimics a sharp, twisting dive and the abrupt pull up on the outrun they are so fond of
for Prairie falcons and Peregrines, a long, low horizontal rotation with a slower pull up mimics a longer, swooping dive from above.
Accipiters are generally allowed to hit the lure each time, feeding a meal divided over six to ten stoops.
Gyrfalcons, Merlins, and Prairie falcons excel at lure flying and will enthusiastically make 75-100 runs with a full meal only at the end as lure flying closely mimics their natural tendency to make multiple short stoops while on the chase.
Peregrines, with their steep vertical stoops from great heights, are least amenable to lure flying as a sole means of training and will quickly progress to kite or balloon training (up next).
Here are two videos demonstrating lure flying, first with a Peregrine and second with a Lanner falcon:
The Falcons
Lure training is usually the final step in training Accipiters, Kestrels, and sometimes Merlins. However, in order to train the larger falcons to wait on high in the air above us, we need one more step: kite and/or balloon training. Yes indeed grasshopper! In order to get that straight down stoop from 500-1,000 feet we'll need to literally go fly a kite (good for training up to 500 feet or so) or even a helium balloon (necessary for training to wait on 1,000-1,200 feet up).
Prairie falcons tend to want to hang out around only 300-400 feet or so and have short attention spans. Gyrfalcons can be trained to climb higher but have even shorter attention spans, with a tendency wander away fairly quickly. It's with the Peregrine (and Peregrine crosses) that this classic training and hunting style really comes into it's own.
Okay, time for us to go fly a kite! Using Caleb's Peregrine, Fighter Pilot, we'll first walk through a photo essay of how this works followed by a couple videos, shot both from the ground and from the kite/balloon.
Our kite:
With 500 feet of main line marked in 100 foot increments (a drill or a winch is super helpful here):
This whole method of training the falcon to go up to the height of the kite/balloon is based on having a food lure attached about 20 feet below the kite.
Here we see the lure leash with the food attached to the leather straps, the leash attached to the main line with a D-ring, and the apparatus held temporarily in place below the kite with a friction clip (a glorified clothespin, really).
The loaded lure:
The lure leash friction clipped to the main line:
Up she goes (the friction clip is yellow in this set up):
Once the kite is at the desired height, we send the bird up:
Approaching the lure at 500 feet:
Grabbing the lure (note the slack between the yellow friction clip and the lure itself):
Fighter Pilot has pulled the yellow friction clip free:
Now he'll ride the lure leash down the main on the D-ring just like running a Zip line:
Successfully on the ground with his prize:
Once the bird is doing this reliably, a pigeon can be released underneath the kite - the falcon will almost always dive for it.
Once he's doing that well, the kite can be eliminated with the pigeon only released when he reaches the height he's been trained to attain.
Once he's doing that well, we're essentially hunting now, no?
Video of the above photo essay:
Video from the perspective of a balloon at 1000 feet:
Video of Fighter Pilot flying on a pigeon sans kite:
Whew! That was another long one! If you've been following on Facebook, you know that Tonks & Dora have been hunting for about two weeks already. Now that we've gotten some of the background info down, next week we'll hit the ground running!
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As we learned last week, falconry is a hunting sport and the type of raptor you decide to fly is determined almost entirely by the type of game you have access to. So, we have our permit(s) and our sponsor and we've settled on a species to fly. How do we go about actually getting a raptor? There are really only two options here: captive-bred or wild-caught.
Sisters Tonks & Dora as captive-bred juveniles
Captive-Bred
The captive breeding of raptors was originally developed to help the Peregrine populations recover from the pesticide DDT and has has been perfected for 50 years now. (A separate Propagation permit is required to do this). Harris' Hawks and Goshawks are the most commonly available captive-bred hawks, while nearly all of the common falcons, except Prairie falcons and kestrels, are readily available from reputable breeders. All captive-bred raptors must have a seamless gold USFWS band applied within two weeks of hatching to be eligible for sale.
Advantages:
-known genetics suitable for falconry
-high probability of being free of pre-existing injury or disease
-will already be habituated to the presence of humans
-no pressure on wild populations
Disadvantages:
-much more expensive than wild-caught ($50 vs $1,000 - $5,000)
-no hunting skills whatsoever at the time of acquisition
-non-releasable (must be sold or given to another falconer)
-only 24 states allow Apprentices to hold captive bred birds on permit
Dora's seamless band
Wild-Caught
All but two states allow raptor capture permits to some degree, with many states allowing up to two capture permits per year. The USFWS 2009 Environmental Assessment documents that falconers have no biological impact on wild raptor populations, capturing only 998 of 3,100,000 juvenile raptors each year (0.03%). It should be noted here that apprentices are not allowed to take a pre-fledgling (eyas) from the nest - they must catch a passage raptor, defined as a juvenile in it's first year from the time it leaves the nest until it's first molt.
Advantages:
-inexpensive compared to captive bred birds
-will have already been successfully hunting for several months on its own
-releasable (under appropriate circumstances) if necessary
-many species are only available as wild-caught birds
Disadvantages:
-higher incidence of hidden injury, disease, or malnutrition at time of trapping
-not acclimated to humans
-become progressively less amenable to training the later in their passage year they are trapped
Raptor Capture table from USFWS Environmental Impact Assessment showing just how few raptors are removed from the wild for falconry:
There are numerous accepted methods of safely trapping a raptor from the wild, but most falconers are reticent to discuss these methods in public forums. For those prospective falconers who are interested, my friend Ben's book Trapping Essentials is the gold standard of current publications. For now, let's assume we've caught our dragon and move on to how we're going to go about training her.
This last picture is of Lily, our Red Tailed Hawk, 30 minutes after we got her home last fall. She's in classic "I'm about to be eaten by a large predator" posture, which is certainly understandable given the events of the last hour or two. So how are we going to going to get from here to willing hunting partner? Well, I'm going to break from tradition right off the bat and tell you the very first thing we're going to do: nothing. We're going to put her on an indoor perch, turn off the lights, and not come back until tomorrow.
The process of acclimating a wild raptor to a human is called manning and traditionally this meant getting her used to sitting on the glove while the falconer walks around, exposing her to various stimuli repeatedly until she learns to stay put. Sure, we need to be able to handle her - install jesses, clean feet, trim beaks, etc. but standing on the glove is not our end goal and the lessons learned in traditional manning are counterproductive to the end goal of an enthusiastic hunting partner.
See, behavioral studies (which I wish I knew about when I started and which I think should be required reading for anyone working with raptors) show raptors are just as susceptible to PTSD and learned helplessness as we are. From the bird's perspective, nothing reinforces helplessness faster than the trauma of repeatedly finding yourself hanging upside down from the glove after unsuccessfully bating away from fearful stimuli you know you can't escape.
Lily calm and collected the next morning:
We do need her to come to the glove though, so how? We're going to give her the freedom to make as many decisions as possible, as soon as possible, using food as a positive reinforcement. A raptor will rarely turn down free food, but she won't really work for it unless she's at or close to her ideal hunting weight. Indeed, raptors in the wild spend 93-94% of their time perched and less than 1% of their time actively flying after game. (Yarak is the falconry term that refers to the combination of ideal hunting weight and mental focus on the hunt). Finding that ideal weight is the key to training.
First, we'll approach VERY slowly and offer a little tidbit of meat for her to pick off the glove - at head level and while she's on her perch. "Wait, what? You haz food...for me?" Every raptor I've trained has gotten at least this far by the morning after trapping.
Next, maybe after a couple days of this, we'll offer food at foot level -- and this is a pretty big deal for her in terms of trust because she'll have to expose the back of her neck to you, which is a big no-no they teach in Survival 101 class.
As we approach our target hunting weight, we'll move from the perch to a plank - anything will work as long as it's about 6-8 feet in length. She sits on one end with us at the other. A piece of food is placed on the plank just far enough away from her that she'll have to take one little step - but a step in our direction - to get it. This is the funniest part to watch as she'll comically stretch and stretch and stretch to try to avoid taking that little step. She will though, and in a day or two will zoom right down the whole length of the plank, grab her food, and zoom right back to her spot every time.
We're about seven to ten days out now and it's time for her to step onto the glove for her food - just a step initially, then a one-foot hop, then two or three feet. A day or two more and she'll fly 20 feet across the room without hesitating. Bam! She's coming to the glove - and riding around on it - of her own free will because that's where the food happens, first directly and later because that's how we get from the car to the hunting field.
Now it's time to move this whole production outside, where there are more distractions. We'll use a lightweight long line called a creance and start at the beginning, first with a one-foot hop, then two, etc. She should be flying 50-100 feet to us in less than a week. Once she's done this a couple times that's it. We're done and it's time to be in the field. I'm leaving a couple tricks out here, but overall no more good can come from continuing to do this routine at home. In fact, to continue to do so tips into a common problem with worry warts everywhere: over-manning. You're making her do the work but without the emotional reward of chasing and catching prey. This makes for an angry, resentful, fist-bound hawk. As the adage goes: The solution to nearly every raptor behavioral problem is more hunting and less training!
Dora on a creance
Lily flying on a creance at the park:
Lily flying on a creance initially then free:
Lastly, we'll do a few untethered free flights in the area we actually want to hunt, which naturally segues into the actual hunting part as hunting is just a longer walk with fewer tidbits offered. As you can see below, even when we pull the glove down and she passes us, she's not going anywhere - she's following along and her focus is in and around us looking for food.
Once we're hunting I really only hold them on the glove to go to and from the car. For the entire hunt itself, they're free to either ride atop the T-perches or follow along from tree to tree. Again, give them the freedom to make their own decisions as much as possible. They'll pretty quickly learn that game jumps up in front of us and that's where their attention needs to be focused.
Does this mean things don't always go according to plan? Sure - Dora is famous for disagreeing with me on which way to walk next.
Does this mean my birds are a little wilder than they could be? Sure - but raptors are highly intelligent and they don't like being made to do busywork anymore than I do.
Does this mean you might lose her? Sure - but staying is always her choice anyway and in the age of GPS & telemetry, it's worth the risk to fly early and often. Besides, she's a lot less likely to want to leave if she's having fun and feels like she has a say in the matter.
In part two we'll talk about Harris' Hawks and falcons, as they're a bit different in ways that merit some discussion.
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First and foremost, falconry is a hunting sport - falconry birds are not pets and you are legally required to hunt with them for a minimum of 4 moths per year, although 3-5 days a week for 6 or 7 months of the year is more typical of the time commitment required. Indeed, in many states you will be required to file an annual report with your Fish & Game department detailing days afield and game caught for each bird you have on permit in order to keep your license.
The granular details of becoming a falconer are beyond the scope of this blog but here is the Cliff's Notes version:
There are three classes of falconer:
-Apprentice (first 2 years, one bird allowed on permit)
-General (next 5 years, up to three birds on permit)
-Master (after 7 years, unlimited number of birds on permit, only 5 may be wild-caught)
In order to become an Apprentice falconer you must:
-pass a written exam (at 80%) on regulations, husbandry, training, hunting, and medical care for raptors
-build an indoor or outdoor (or both) raptor enclosure , which must pass inspection by fish & game
-obtain equipment from the minimum equipment list, which will also be inspected by fish & game
-obtain a sponsor (a general or master falconer with 4+ years of experience) willing to tutor you for those first two years
Convincing an existing falconer to sponsor you is usually the tallest hurdle to clear and it may take a year or more to convince a prospective sponsor that you're serious about this. Sponsoring an apprentice is a major undertaking and falconers are used to having excited people come out of the woodwork every time there is a raptor in a TV show or movie only to have them fade away a week or a month later. The Harry Potter years were particularly trying for potential sponsors in this regard.
Given all of these requirements, the number of licensed falconers in the U.S. has remained steady at only 4,000 for decades, with falconers heavily concentrated in the Central and Pacific Flyway states as that's where the most diverse hunting opportunity is located.
So, we've made it this far and have our permits - what do we want to fly? Not so fast grasshopper! If you're an Apprentice, you're likely to be flying either a Red Tailed Hawk or American Kestrel for those first two years.
Here's the breakdown on that:
- six states allow Apprentices to fly Red Tails only
-19 states allow Apprentices to fly only Red Tails or Kestrels
-seven states allow Apprentice to fly Red Tails, Kestrels, or Harris Hawks
-two states allow Apprentices to fly any of the 14/34 species on their approved species lists(s)
-15 states allow Apprentices to fly any raptor not listed as threatened by the USFWS
In all but six states you have at least some choice of raptor, so how do you choose? Remember, falconry is about hunting -- your choice of raptor is entirely dependent on the type and abundance of game you can consistently provide her the opportunity to hunt. The Peregrine and the Gyrfalcon are very cool birds but they require a lot of open space to hunt and they're almost exclusively avian predators. If you don't have access to game birds like waterfowl, pheasants, or grouse they are right out. Likewise, a Red Tail, Goshawk, or Harris Hawk is going to need either the same menu as above or abundant rabbits and squirrels to be happy.
In general, the larger the bird the more open space you'll need and the more highway miles you'll travel. We live in ideal hawking habitat but still average 12,000 to 15,000 miles a year driving the hawks to and fro - and some of my friends who fly Peregrines easily triple that. In fact, it made more sense for us to have a dedicated hawking car than to put that many annual miles on our primary vehicles.
Our hawking car , AKA the falcon mobile :
So is a suburban teenager or an adult that works until six every day out of luck? Not at all! European Sparrows, Starlings, field mice, and voles are ubiquitous and hunting them right in town with a Kestrel or Sharp-shinned hawk every day after work or school might be just the ticket. Add in some nearby farmland with Starlings and Pigeons and Merlins, Aplomados, and even Cooper's Hawks become feasible as well. Again, the game you have realistic access to dictates the species of bird you should consider flying.
I'll wrap this up with a series of videos showing a variety of hunting styles, from suburban to rural. Note how, as the birds get bigger, so does the space needed to fly them.
Kestrels can be flown nearly anywhere, from city parks to fence rows on the edge of town:
Tonks & Dora hunting jackrabbits in the sage from their T-perches
My friend Missy soar-hawking her Ferruginous Hawk Skully
My friend Caleb flying his Peregrine Fighter Pilot
Next week: How to train your dragon (part 1)
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Falconry, defined as the use of trained raptors to hunt small game, is believed to have originated in Mongolia around 2,000 B.C. and to have subsequently migrated across Europe and Asia via trade routes from the second to fourth centuries A.D. By the fifth century A.D., equipment , terminology and training techniques were pretty much standardized across all of EurAsia, with only minor regional variations. Indeed, with the exception of the use of radio telemetry & GPS tracking, the equipment and terminology used in falconry has remained essentially unchanged for the past thousand years.
-----Fun sidebar: Here are ten common English terms that have their origin in Medieval falconry !--------
One of the earliest complete texts on falconry was published in 1250 A.D. by the Roman Emperor King Frederick II of Hohenstaufen. Far more than a memoir, Frederick's extensive analysis of avian anatomy, physiology, and ecology is considered to be the earliest known work to employ the critical thinking principles of what would become the core of the modern scientific method -- written over 750 years ago, this book is still in print and the majority of it's observations are still considered to be scientifically accurate today.
Bird Nerd Alert: King Frederick has had such as lasting impact on falconry that he has his own official Falconer-Holiday - the 3rd Saturday in October is "King Frederick's Day". Don't miss it! :)
By the middle ages, falconry had truly become the "Sport of Kings" , especially in Europe -- the 1450 publication Booke of Hawking After Prince Edwarde Kyng of Englande details the restrictions on keeping raptors by social rank:
- Emperor: Eagle, Merlin
- King: Gyr Falcon (male & female)
- Prince: Peregrine Falcon
- Duke: Rock Falcon (subspecies of Peregrine)
- Earl: Tiercel Peregrine (male)
- Baron: Bastarde Hawk or common buzzard (a red-tail sized hawk)
- Knight: Saker falcon
- Squire: Lanner falcon
- Lady: Female Merlin
- Yeoman: Goshawk or Hobby (a Merlin-sized falcon)
- Priest: Female Sparrowhawk (a small Accipiter)
- Holy water Clerk: Male Sparrowhawk (a small Accipiter)
- Knaves: Kestrel
- Servants: Kestrel
- Children: Kestrel
the golden eagle, the Gyrfalcon and the Peregrine falcon were traditionally reserved for the Royal Family:
While the Goshawk, sparrowhawk (similar to the Sharpie shown below), and kestrel were the only raptors commoners could keep:
photo @Rebecca Bledsoe
In North America, falconry wasn't actively regulated until the early 1970s, when the Peregrine was added to the Endangered Species List as a result of the widespread use of the pesticide DDT. In response, a group of dedicated falconers started a non-profit organization called The Peregrine Fund to research and develop a captive breeding technique using artificial insemination -- both to help recover the Peregrine populations in the wild as well as provide a sustainable source of non-wild Peregrines for use in falconry. The techniques they developed (google a video of this sometime, it's hysterically funny to watch!) were so successful the wild Peregrine population was officially listed as recovered across the US. less than 30 years later.
Headquartered in Boise, Idaho, the Peregrine Fund maintains the largest scientific library on avian biology in the world and is currently working to recover the California Condor, the Andean Condor, and the Aplomado falcon. Captive breeding programs, based on the techniques developed by the Peregrine Fund, are the source for the majority of raptors used in falconry today.
Around the same time these falconers were working with the U.S. Fish & Wildlife Service on wild Peregrine recovery, they were also working with the Service to create a modern, rigorous Federal falconry statute that ensures both the safety and well-being of individual falconry birds as well as preserving wild raptor populations across the U.S. In 2007 the Federal government turned over day-to-day falconry regulation to the states, provided the state regulation was at least as rigorous as the Federal statute. Currently Hawaii is the only state that does not have an approved falconry program.
Bringing us full circle, at the urging of a committee led by the United Arab Emirates, the United Nation's cultural arm (Unesco) designated the practice of falconry as an activity integral to our common human heritage in 2010.
There! Four thousand years of history in 4 minutes! We'll get to the nuts & bolts of those falconry regulations later, but for now here's a teaser for the upcoming season:
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If you're following from said prior platforms, welcome back! If you're new to the concept, I , my wife, and my eldest daughter are licensed falconers and we hunt with three female hawks -- two sibling Harris' Hawks named Tonks & Dora that hunt together and a Red-Tailed Hawk named Lily that hunts solo.
We hunt roughly four days a week from August to March, mostly for rabbits and pheasants. March to August is our off-season when the birds are molting a new set of feathers.
Tonks and Dora are starting their fifth season now , and are at the very peak of their game -- in a typical year catching enough rabbits to see themselves through both the hunting season as well as the molt.
Tonks & Dora back in the mew after having spent the summer free-lofted in the outdoor flight chamber:
Tonks and Dora have completed their molt and are about 2-3 weeks away from getting into the field.
Lily is a little farther behind - she still has about a month of feather-growth to complete (as well as waiting for a little cooler weather).
I'm sure it'll take me some trial and error to figure out all the controls on this platform - not to mention migrating all my photos and videos from elsewhere. As we go, I'll include background posts on all the behind-the-scenes stuff that has to happen to keep the birds happy, healthy, and in compliance with the rigid state and federal laws regulating falconry. I'll also leave the comments section turned on for discussion.
Hope to see you again soon!
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