As I’ve mentioned in previous posts, my master’s thesis work involves studying American Kestrels; small falcons that nest in cavities and nest boxes. Keeping up with such quick and mobile creatures can sometimes be exhausting. If I had a hoverboard things would probably be easier, but apparently grad students can’t afford such things. Observing kestrel behavior can often be an enjoyable experience . . . provided I don’t want to finish experiments or accomplish actual work.
One of the fascinating things about kestrels is their plumage. Many raptors in the U.S. have plain brown, gray, or white plumage with occasional touches of reddish-brown or blue-gray. American Kestrels, on the other hand, have rufous and blue and black and white colors. The males are especially beautiful with their blue wings and rufous belly. Kestrels exhibit reversed sexual dimorphism (RSD), where females are larger than males. One of the hypotheses for RSD (not to be confused with LSD, which makes kestrels have a wide variety of colors and sizes) is that the smaller size of males may increase agility in capturing prey items such as insects. Males often provide much of the food during the nesting season so being a good provider would be an important advantage for a male.
This male would make a good provider.
Another interesting thing about the kestrels I watch is that they have different personalities. Some of the falcons are very skittish and fly away whenever I drive up by their territory. I always call out to them in their native tongue (klee klee klee!), but they never listen. One of the kestrels that is often shy is J.J. Abrams. J.J. has frustrated many an experiment by flying from tree to tree and hiding behind the leaves. Other kestrels are bolder and even curious. These kestrels will usually let me get fairly close. Duncan (named for the Dunkin’ Donuts nearby) hunts out in the open near a main road and is used to cars, while Howie and Heidi are a pair that usually behave for my experiments
J.J. Abrams is very secretive, except when you taunt him with an intruder (female model) and playback of alarm calls!
Howie is more open and approachable.
Observing the interactions between a pair of kestrels is also fascinating. Yesterday I saw a male and female circling in the sky together. The show they put on was almost as entertaining as the presidential debates. The female would make a pass at the male and then he would make a pass at her. They also called out to each other and did various swooping displays. I wonder if swooping displays and singing would work for me? Anyway, I’ll talk more about the behavior of my kestrels and some of the cool things I’ve seen in my field work (including falcon fights!) in my next blog. For now, I leave you with a short clip of kestrel nestlings peeking out of a nestbox.