A better understanding of feeding ecology and parental roles is important for conservation of Ferruginous Hawks (Buteo regalis) and their habitat. In 2004–2005, we collected and analyzed 1373 hr of video from six time-lapse video-monitored nests in New Mexico, U.S.A., to address these behavioral data gaps. Ferruginous Hawks delivered 93 g of prey biomass per hr to each nest (g/hr), 42 g/nestling/hr, and 208 g/prey delivery. Males delivered most prey items (72%) and twice the overall prey biomass of females, but females delivered larger prey items in each delivery. As predicted by the food-niche hypothesis, males and females used prey differently, with females delivering a disproportionate number of desert cottontails (Sylvilagus audubonii) and males delivering Botta's pocket gopher (Thomomys bottae) most often. Desert cottontails, the heaviest prey item, were most often delivered eviscerated. Females spent 33% of recorded time at the nest, whereas males spent <1%. We found a positive relationship between female nest attendance and male provisioning rate, and a negative relationship between female nest attendance and nestling age; the role of the male was to deliver prey whereas the female's initial role was to feed and care for nestlings, then to find food as nestlings began feeding themselves and became homeothermic. Evidence of intersexual differences in prey use may provide managers justification to focus limited resources on actions that create habitat heterogeneity and, consequently, a more diverse prey base.

Cooper's Hawks (Accipiter cooperii) from approximately the northern third of the species' breeding range are considered migratory, hawks in the central portion are either migratory or resident, and hawks farther south are believed to be nonmigratory. We compared long-distance movements (>100 km between natal nest and encounter location) of Cooper's Hawks banded as nestlings at two different ranges of latitudes (>35° and <35°N). Our goal was to determine whether long-distance movements indicate that Cooper's Hawks from southern latitudes (south of 35°N) are migratory and whether any migrate north, as do Bald Eagles (Haliaeetus leucocephalus) from several locations in the southern U.S.A. and Red-tailed Hawks (Buteo jamaicensis) from southern California. Long-distance movements by hawks banded as nestlings north of 35°N were strongly oriented to the south, with only 17% in a northerly direction. The only hawks encountered >100 km from nests south of 35°N were from southern Arizona and southern California. As opposed to the strong southward orientation of long-distance movements of hawks from north of 35°N, mean direction south of 35° was bipolar. Northward long-distance movements from nests in southern Arizona were relatively short (<200 km), while southward movements were substantially longer (1637 km in one case). Three Cooper's Hawks from southern Arizona were encountered in central Mexico, well south of the known breeding range, which suggests some individuals from southern Arizona are migratory. The pattern of long-distance movements from southern California was the reverse of that from southern Arizona. Most long-distance movements toward the south from southern California nests were comparatively short, whereas the three longest movements from that area (616–993 km) were to the north. Although tentative, we believe these longer movements are indicative of northward migration rather than natal or breeding dispersal.

We determined breeding-site selection of Northern Goshawks (Accipiter gentilis) by comparing 33 breeding sites to 40 nonbreeding sites at the small (nest tree and vegetation structure within an 11.3-m radius of the nest) and the large scale (biomass of prey species and landscape structure within a 500-m radius from the nest) in the urbanized area of Kanagawa Prefecture, Japan. Goshawks selected primarily Japanese cedar (Cryptomeria japonica) trees over 50-cm diameter at breast height (DBH) as nest trees. Trees smaller than 35-cm DBH were avoided. We used univariate logistic regression to assess vegetation structure of the nesting area. At the small scale, canopy trees in the nest plots were larger and taller, with more canopy cover, than those in non-nesting plots, and nests were farther from human habitations. In addition, nest plots had fewer understory trees than non-nest plots. In multivariate logistic regression, the DBH of canopy trees, number of understory trees, and distance to human habitation were highest in importance. At the large scale, nest plots had a greater percentage of forest area, smaller percentage of built area, more forest edge facing open land, and more forest edge facing PCDRS (parks, cemeteries, developed land, recreational fields, and small-scale vegetated areas <0.01 km² in a matrix of ≥30% residential areas). In the multivariate model, the length of forest edge facing open land and the percentage of built area were of highest importance.

The Snowy Owl (Bubo scandiacus) is a circumpolar raptor that nests in Arctic tundra. Satellite tracking of nesting Snowy Owls in Alaska and eastern Canada has allowed researchers to document the widely nomadic movements of these owls between summer and winter ranges. This study expands that knowledge for Snowy Owls in the western Canadian Arctic. Based on previous studies, we predicted that owls: (1) would not have strong fidelity to specific winter or summer ranges; (2) would travel widely in search of breeding and nonbreeding areas at which they would settle for considerable time (months); (3) would choose areas to settle based on prey concentration; and (4) would use a mix of overwintering strategies, with some staying in Arctic and boreal regions, and some migrating south. Movement patterns of four female owls captured at nesting sites on Herschel Island, Yukon Territory, Canada, supported the first two predictions. The third prediction was partly supported: some sites of summer settlement were located where prey was relatively abundant, whereas other selected sites did not appear to have enough prey for successful nesting. The latter sites may have been the best available in those areas, however. Sites of winter settlement generally overlapped regions with high abundance of snowshoe hares (Lepus americanus) or ptarmigan (Lagopus spp.), and were located in relatively open alpine, subalpine, or wetland environments, where prey were likely most accessible. Contrary to our last prediction, all four study owls settled in boreal Alaska and the northern Yukon Territory. This pattern contrasts with observations that eastern North American Snowy Owls rarely wintered in the boreal biome. This study highlights the need to better understand the habitat choices and food habits of wintering Snowy Owls in the northern boreal mountains.

The movement ecology of Harpy Eagles (Harpia harpyja) is poorly known due to the difficulty observing this species. We studied the movements of two juvenile Harpy Eagles before and during dispersal using GPS satellite telemetry in the Reserva de Producción Faunística Cuyabeno, Ecuador. Both eagles were tagged at their respective nest tree. For each eagle, we calculated the daily distance moved and the distance from each recorded position to the nest. One eagle started dispersal during its 28th month, while at the same age the other eagle remained in its nest area, suffering repeated parental attacks that may have caused its death. The juvenile that dispersed moved a maximum of 35.1 km from the nest and occupied an area of 386 km². The long post-fledging and dispersal periods underscore the importance of directing conservation plans toward juveniles as well as adults. In addition, dispersal movements that are close to the natal nest facilitate the delimitation of areas for protection of Harpy Eagle nests.

The index includes references to general topics, common names, key words, and authors. Reference is also made to book reviews and letters. Taxa other than raptors are included where referenced by authors.