Fluffy Little Monsters

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A couple weeks ago when I was writing about our serendipitous discovery that one of our kestrels will act as a foster parent, I was having a great deal of difficulty staying on topic.  I kept wanting to write about the morbidly fascinating behavior we see these lovely little birds displaying every day.

As you can probably imagine, the people who visit and work at TreeHouse tend to be pretty big animal lovers, and sometimes it’s hard for them to see the freezers full of dead mice, rats, chickens, deer—whatever we have on hand at the moment.  It’s important to understand, though, that some animals eat other animals, and you will never convince a hawk to turn vegetarian.  We care for a lot of carnivores at TreeHouse, and we want to give them as wild and natural a life as possible.  It would be totally impractical to provide our permanent residents with live prey regularly—for one thing, many of them have injuries that impede their ability to hunt.  Still, we try to feed them as naturally as is feasible.

For anyone who is particularly sensitive about this sort of thing, it might be wise to avoid the kestrel enclosure around feeding time.  Kestrels are beautiful birds, and their small size gives them a deceptively delicate appearance.  But when they hunt—and when they eat—they turn into little killing machines.  Personally, I find it fascinating.

Hawks kill their prey with the talons of their powerful feet.  Kestrels, however, as falcons, catch their prey with their feet but kill by breaking the neck with their beaks.  When one of our kestrels gets a mouse, its first move is always to carry it to a perch and begin tearing at the neck with its beak.  Then it rips the head off.  Actually, to be more precise, it tears at the neck until the head is just dangling by a thread.  Then it proceeds to eat the brain.  I’m not really sure why they go for the brain first.  Maybe it tastes good.  I’ve also heard anecdotally that the brain will decay more quickly than the rest of the body, so maybe it has to do with eating it while it’s still fresh.  In any case, this leads to one of the more disturbing things our kestrels do: they don’t usually eat the whole head; instead, they leave the facial bones and flesh intact.  Then, often, they leave the faces on the platform where we feed them.  I don’t know if they’re trying to make some sort of statement or if it’s just convenient—probably the latter.  Either way, it’s super creepy.

Braaaiiins!!!

Once the kestrel is finished with the head, it moves on to the rest of the meal, gleefully ripping out entrails and chunks of meat.  If it’s really hungry, it will eat the mouse whole, later coughing up the fur and bones in a pellet.  Other times, it might be pickier.  Being “pickier” means that along with the face, we might find the spine, with tail still attached, lying on the platform.  Maybe I’m just weird, or maybe any 80s or 90s kid would have the same response, but when I see that, the “spine rip” move from Mortal Kombat always pops into my mind.  I think if a kestrel could play video games it would probably like Mortal Kombat.

If the kestrel really isn’t hungry, it might not be able to finish a whole mouse.  In that case, it will save its leftovers for later.  Our kestrels save their leftovers by hanging them in the Christmas tree.  Like ornaments.  To explain, the Christmas tree came with the house when we moved to our new location.  We wanted to find a use for it, and we thought that it would be perfect for the kestrels, as it would contribute to the diverse, naturalistic habitat we were trying to create for them.  And apparently it has.  They sometimes roost in it, and they frequently drape pieces of their food in it.  Like tinsel.  It’s a little bit gross, but mostly interesting.

Trimming the Christmas tree.

Ultimately, if hippos are the killer clowns of the animal kingdom, I’m pretty sure kestrels are the psychotic serial killers who keep trophies of their victims in the basement.  Though they say it’s always the quiet ones, and kestrels are anything but quiet.  Really, they’re just wild animals—predators that are supremely well-adapted for the niche they fill in nature, catching birds in flight and other small, fast things.  When I’m driving down a country road and I see a kestrel shoot through a flock of sparrows and grab one out of the air, I feel a twinge of pity for the sparrow, but mostly I’m delighted to witness nature in action.  It’s the circle of life!

Foster Father of the Year

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Yesterday, we admitted a young kestrel—our first this year.  She was transferred to TreeHouse by a private rehabber with whom we often work, after being found in a parking lot standing on someone’s car. The kestrel is a brancher. “Brancher” is a term used to describe juvenile raptors at the age when they have flight feathers but have not yet learned to fly.  At this age, they will hop around from branch to branch and down to the ground as they explore their surroundings, but they normally remain fairly close to their nest, as their parents are still feeding them.

The brancher sits on top of a post in the outdoor cage.

The kestrel we admitted yesterday seems to have no physical problems, but she is still too young to feed herself in the wild.  Since she was found in the middle of a parking lot, she had evidently strayed farther from her nest than is usual.  The location of the nest was unknown, so we brought her to TreeHouse until she is old enough to hunt on her own.

Although she is not yet hunting, she is old enough that she will pick food up on her own, so we placed her in our outdoor cage with our three permanent resident kestrels.  It is important to place juvenile birds with adults of the same species whenever possible, so that the adults can serve as behavioral role models and prevent human imprinting.  This particular kestrel is past the age at which human imprinting is a serious concern, but it is still beneficial for her to be with others of her species.

When Adele and I placed the kestrel in the outdoor cage yesterday, we were lucky enough to witness a very cool interaction between the brancher and one of the resident adults.

In most bird species, the chicks have a distinctive food-begging cry to which their parents respond instinctively.  When an adult hears this feeding cry, it is impelled to find food and bring it to the chick. This instinctive drive is what makes it possible for us to use non-releasable adults as foster parents.  An adult bird will typically respond to the feeding cry even if the young bird begging for food is not its own offspring.  Still, it usually takes a few days after a chick is introduced for the foster parent to adjust to the change and start actually caring for it.

In the case of our brancher kestrel, we were not expecting the adults to act as foster parents.  None of them had any previous experience fostering chicks, and the brancher is old enough to pick food up for herself.  But shortly after we placed her in the cage, she started the food-begging cry.  This in itself was not surprising.  Kestrels are notorious among wildlife rehabbers for the migraine-inducing clamor young orphans will make as they constantly demand food.  What did surprise us was the reaction of one of the adult residents.

This is Quincy, the adult permanent resident who adopted the new brancher.

As soon as the brancher started begging, one adult turned to watch her.  Within about a minute, he flew to the Christmas tree where the kestrels like to hang pieces of mice and picked one up in his talons.  (As an explanation about the Christmas tree food storage, I’ll have to follow up soon with an article about the kestrels’ normal feeding behavior—it’s pretty fascinating.  They’re like tiny feathery psychopaths.)  He then flew to where the brancher was perched and handed her the piece of mouse, from his beak to hers.  She picked at it for a few moments, then, like a toddler making trouble, dropped it on the ground and started crying again.

The adult watched her for a minute, looking back and forth from the mouse on the ground to the trouble-making brancher, and then he hopped to the ground, picked up the mouse, and brought it to her again.  This time she picked at it a little longer before dropping it on the ground, and she didn’t start crying immediately afterwards, so she must have had enough.

Of course I don’t have any pictures or video of this interaction—I never have my camera when something that interesting happens.  Now I just have an excuse to camp out next to the kestrel cage until I see it happen again.  Witnessing this sort of behavior really is my favorite thing about working at TreeHouse.  I could never get tired of observing wild animals and their behavior, and it seems like every day I see something amazing that I’ve never seen before.

Quincy and the brancher. In kestrels, unlike most of the raptors we have at TreeHouse, it is easy to distinguish between the sexes. Males are vividly colored, while females have more muted coloring.