Both the male and female of the Boise Downtown Peregrines are doing quite well. The tercel is helping the female in incubating and he brings her prey. There has been some discussion of how one can tell the male from the female when they are not together. The Peregrine Fund gives us some good information on this. From their website,
… The easiest way is to observe the difference in their size – the female is larger and heavier. Admittedly, judging this pair’s relative size is difficult when they aren’t side by side but viewers should be able to discern the difference over time. Also, look for subtle differences in their markings. This female’s color is duller and her head appears more solidly dark, while the male is brighter and has white on the sides of his head.
The size difference is called reverse sexual dimorphism and is common among falcons, hawks, eagles, and other birds of prey. “Reverse” refers to the fact that males are larger in most other species. Experts suspect that this adaptation evolved so that a pair can pursue a wider variety of food. The female’s more powerful size enables her to capture and transport larger prey and the male’s smaller size gives him greater agility. It may also have something to do with the female’s ability to defend the nest and provide larger prey items for the chicks when they are older.
I do hope this helps you to ID the falcons as they are flying around downtown Boise or you spot them on one of the buildings. Do let us know when and where you see them. Or, if you get a good photograph of the Boise falcons, send it to us and we will post it here on the blog for you, with your credit. Cheers and Keep Looking Up!