Leon R. Powers

In the 1970s, the author was a graduate student at Idaho State University, working toward his PhD in Zoology. He wrote a 300-page dissertation on ferruginous hawks. This book is a shorter, less-scientific version of that dissertation.

Ferruginous hawks are the largest hawk in North America. They are also very shy birds, so they are considered a good barometer for measuring the encroachment of man. Flying away, and abandoning a nest, if people get too close, is possible for them. The author chose to study ferruginous hawks because so little was known about them.

Several nests in southern Idaho and northern Utah were chosen for observation. Some nests are set up in juniper trees, only a few feet off the ground, and some are set up on the ground. Most of the observations had to be done from blinds set up a couple of hundred yards away. The nests are big, anywhere up to several feet across. The hawks, especially the chicks, have developed ways to deal with the sun beating down on their nests (there is no shade nearby). The nests in the trees are not high enough to prevent attacks by predators, especially coyotes, as the author observed one day.

A couple of times, while the adults were away, Powers would climb up to the nests and feed the chicks miniature transmitters. These were intended to measure their internal body temperatures. After excretion, the transmitters were not found at the base of the trees, as expected. Adult hawks pick up bones, caracsses and droppings, and deposit them several hundred yards away, so the smell will not attarct predators. For a time, there was a shortage of jackrabbits (the main food source for the hawks) in the area. Powers was interested in seeing if the hawks would make do with whatever they could find as substitutes, like snakes, rats and lizards.

This is a really interesting book. The author’s passion for his work and "his" hawks shows through everywhere. For those interested in nature and the environment, whether actively or of the armchair variety, this is very much worth reading.… (altro)