Is unpalatable food properly digested?

The effects of management practices on grassland birds—Ferruginous Hawk (<i>Buteo regalis</i>)

“…Primary prey items in western shrubsteppe are jackrabbits (Lepus spp. ), followed by ground squirrels and pocket gophers (Smith and Murphy, 1978;Olendorff, 1993;Ng and others, 2017). White-and black-tailed prairie dogs also serve as prey items (Powers and Craig, 1976;MacLaren and others, 1988;Giovanni and others, 2007).…”

“…In Oregon shrubsteppe, 17 nests were in short (mean=4.8 m) western juniper trees, were <10 m above the ground, and had large support branches (Green and Morrison, 1983). In Washington, Idaho, and Utah, several studies revealed that nests were <10 m above the ground in western juniper or Utah juniper trees (Howard, 1975;Woffinden, 1975;Howard and Wolfe, 1976;Powers and Craig, 1976;Fitzner and others, 1977;Smith and Murphy, 1978;Woffinden and Murphy, 1983;Hansen, 1994). In Utah, nests were constructed 2-3 m above the ground, were most commonly located on the sides or summits of hills, and often had southern or eastern exposures (Weston, 1968).…”

“…Ferruginous Hawk densities and productivity are closely associated with cycles of prey abundance (Woffinden, 1975;Powers and Craig, 1976;Smith and Murphy, 1978;Smith and others, 1981;Gilmer and Stewart, 1983;Houston and Bechard, 1984;White and Thurow, 1985;Schmutz, 1989Schmutz, , 1991aSchmutz and Hungle, 1989;Poulin and others, 2001;Schmutz and others, 2008;Ng and others, 2017). Mammals are the primary prey during the breeding season, although birds, amphibians, reptiles, and insects also are taken (Weston, 1968;Howard, 1975;Fitzner and others, 1977;Blair, 1978;Smith and Murphy, 1978;Gilmer and Stewart, 1983;De Smet and Conrad, 1991;Hansen, 1994;Giovanni and others, 2007;Schmutz and others, 2008). Primary prey items in grasslands east of the Rocky Mountains are ground squirrels (Urocitellus spp.…”

“…In Nebraska and North Dakota, Ferruginous Hawks preferred large blocks of native prairie (Stewart, 1975;Faanes and Lingle, 1995). Estimates of home-range size ranged from 3.14 to 8.09 square kilometers (km 2 ) in the Columbia River Basin and Great Basin regions of the Western United States (Smith and Murphy, 1978;Janes, 1985;Olendorff, 1993). The average home-range size for Ferruginous Hawks was 90.3 km 2 in Washington, and the variability in home range was significantly related to distance from the nest to the nearest irrigated agricultural field (Leary and others, 1998).…”

“…Ferruginous Hawks occur in breeding areas from late February through early October (Weston, 1968;Olendorff, 1973;Maher, 1974;Blair, 1978;Smith and Murphy, 1978;Gilmer and Stewart, 1983;Schmutz and Fyfe, 1987;Ng and others, 2017). Renesting within the same year is rare (Woffinden, 1975;.…”