On the Way Home for the Summer

This youngster was flying over the parking lot at Lyons Woods this afternoon:

Red-shouldered Hawk (Buteo lineatus),
Lyons Woods FP, Lake Co, IL 4/11/2014

This is a Red-shouldered Hawk (Buteo lineatus), hatched last summer. He's on his way north, at least for a bit longer, to spend the summer hunting mostly frogs and snakes.

Habitat loss is a serious, ongoing problem in wildlife conservation, as wild(ish) places get converted to homes, offices, and shopping malls. But some species seem to deal with it better than others. Red-shouldered Hawks have been studied in suburban settings in Ohio (1) and urban settings in California. (2) In Ohio, nest sites didn't differ from those in rural settings -- large, full-canopied trees hosted most nests, usually close to water. Productivity didn't seem to differ either, suggesting that they handle suburban habitats quite well. In California, they again used large trees close to water, and once again the degree of urbanization didn't seem to affect reproductive success. Surprisingly, though, they preferentially nested in introduced Eucalyptus trees, which are apparently larger and more stable than most of the native trees in the area.

These studies were published in 2000. Interestingly, a paper published in 1992 indicated that Red-shouldered Hawks in northern New Jersey avoided suburban areas. (3) Is this difference a matter of geographic variation in the birds, or perhaps due to an overall improvement in our suburban environment? Or perhaps these birds are slowly adapting to people, the way Cooper's Hawks have?

We've certainly got enough areas with different levels of development, and enough variation in species' responses, to start to get a handle on these sort of questions. And if we're going to save as much as we can of our wildlife in the face of continued population growth, we're going to want those answers.

(1) Dykstra, C. R., Hays, J. L., Daniel, F. B., & Simon, M. M. (2000). Nest site selection and productivity of suburban Red-shouldered Hawks in southern Ohio.The Condor, 102(2), 401-408.

(2) Rottenborn, S. C. (2000). Nest-site selection and reproductive success of urban Red-shouldered Hawks in central California. Journal of Raptor Research, 34(1), 18-25.

(3) Bosakowski, T., Smith, D. G., & Speiser, R. (1992). Status, nesting density, and macrohabitat selection of Red-shouldered Hawks in northern New Jersey.The Wilson Bulletin, 434-446.