Ferruginous hawk banding in Saskatchewan

Prey use and productivity of ferruginous hawks in rural and exurban New Mexico

“…In our study, productivity of exurban hawks was similar to that recorded for ferruginous hawks nesting in core breeding habitat (i.e., Canada; Houston and Zazelenchuk , Schmutz et al ), whereas productivity of rural hawks was similar to levels recorded in peripheral habitat (i.e., Utah; Smith and Murphy ). Exurban hawks exceeded the productivity level estimated by Woffinden and Murphy () to maintain a stable population (1.5 fledglings/nesting attempt), but rural hawks barely satisfied it.…”

“…A proportional diet may suggest a level of predatory flexibility that could benefit the persistence of a species in times of low prey availability or an otherwise changing environment. Indeed, strict reliance on the abundance of a single prey species can affect hawks’ breeding productivity (Smith and Murphy , Houston and Zazelenchuk , Schmutz et al ) and may eventually lead to extirpation of hawk populations following a prey population crash (Woffinden and Murphy ). The ability to adjust to changes in prey abundance by altering predatory behavior may be especially important for peripheral populations because they may be inherently more at‐risk than populations in core habitat (Lesica and Allendorf ) but are still in need of conservation attention (Steen and Barrett ).…”

Nesting Pair Density and Abundance of Ferruginous Hawks (Buteo regalis) and Golden Eagles (Aquila chrysaetos) from Aerial Surveys in Wyoming

“…Our total estimate of 94.7 km 2 per Ferruginous Hawk nesting pair suggests that density of nesting Ferruginous Hawks in Wyoming is slightly lower than previous nesting pair density estimates across the range of the species (Table 3). Numerous studies have indicated Ferruginous Hawk populations may be in decline (Woffinden and Murphy 1989, Schmutz et al 1992, Olendorff 1993, with potential causes given as increased disturbance and loss of habitat from energy development and agriculture (Woffinden andMurphy 1977, Houston andBechard 1984). Energy development is extensive across Wyoming, and is particularly intense within the distribution of Ferruginous Hawks (Keinath et al 2010, Wyoming Oil andGas Conservation Commission 2014).…”

Migration Patterns, Timing, and Seasonal Destinations of Adult Ferruginous Hawks (Buteo regalis)

“…The largest known nesting populations are in southern Alberta and Wyoming (Olendorff 1993) and as much as 20% of the known wintering area for this species is in Mexico (Bechard and Schmutz 1995). Significant declines in some regional populations of this species have resulted in its national designation as Threat- (Salt 1939, Gilmer et al 1985, Schmutz and Fyfe 1987, Houston et al 1998, Harmata 1981, Harmata et al 2001. In contrast, juvenile hawks banded west of the Continental Divide at nest sites in Idaho (Thurow et al 1980), and 11 individuals tracked by satellite telemetry from Idaho and Utah ) moved widely throughout the west.…”