Food deprivation and temperature regulation in nestling ferruginous hawks

Call Number:

URL:

Keywords:

Abstract:

The Ferruginous Hawk (Buteo regalis) nests in the semi-arid regions of southern Canada and the western United States. Throughout the breeding range Ferruginous Hakws nest primarily on rocky outcrops, tops of trees especially junipers (Juniperus spp.) and cottonwoods (Populus spp.) and occasionally on sagebrush (Artemisa spp.) or the ground. Despite the high temperatures encountered in the latter stages of the nesting cycles, apparently shade availability is not a nest-site requirement for the species. In the Great Basin west of Utah Lake, Woffinden examined 56 nests of Ferruginous Hawks on rocky outcrops, on the ground, and in trees. Almost half of these nests were unshaded throughout the day. The nests on steep slopes received some shade only in morning or afternoon, depending on slope aspect. Here we present field data suggesting that underfed Ferruginous Hawk nestlings are especially vulnerable to heat stress. We predict that combined effects of inadequate food provisions and high temperatures my cause much nestling mortality in years when prey populations are low.

Notes:

Reference Code: A81TOM01IDUS

Full Citation: Tomback, D. F. and J. R. Murphy, 1981. Food deprivation and temperature regulation in nestling ferruginous hawks. Wilson Bulletin 93(1): 92-97.

Location: ANIMAL EF: BUTEO REGALIS