Last time Aldo was inside due to cold temperatures, he spent some quality time in my office. He kept busy by watching visitors pass by in the hallway, listening to the strange noises emanating from my computer, and, apparently, mimicking the artwork on the wall. The watercolor prints were done by a naturalist that I worked with a few years ago. She painted a variety of animals, but my favorite piece is the male kestrel, shown at the perfect angle to highlight his handsome plumage. The solid block of rusty-brown on the tail and slate-blue wings contrast with the female’s rather plain brown wings and tail.
Such a striking difference is rare in raptors. In most species, there is no difference in plumage. The only way to tell male from female is by size: if you see them sitting right next to each other, the female is the larger one of the pair. With individual birds, it’s a bit of a guessing game. Our Red-Tailed Hawk, Carson, weighs just over 3 pounds. That falls in the upper range of Red-Tailed Hawk weights, so she is likely a female. With Aldo we don’t have to guess: his colors tell us without a doubt that he is male.