Continuing the theme of revisiting aspects of falconry we glossed over in the beginning, this week we'll look a little more closely at some of the hunting strategies the birds use. My kids are convinced we're just randomly walking around in the middle of nowhere but there really is some logic behind how we (and the birds) approach catching game in varying terrain.
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:
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.
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.
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:
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:
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.
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.