We estimated survival for Peregrine Falcons (Falco peregrinus) in beach-dune habitat along the Washington coast. We captured and color-banded 76 Peregrine Falcons during 438 surveys by vehicle on three coastal beaches in Washington from January 1995 to May 2003. We captured 45 females and 31 males; 68% (52) were <1 yr old and 32% (24) were ≥1 yr old. Based primarily on photographs (N  =  72) showing plumage coloration, 76% (N  =  55) of the individuals captured were F. p. pealei, 7% (N  =  5) were F. p. anatum, 3% (N  =  2) were F. p. tundrius, and 14% (N  =  10) showed intermediate characteristics and could not be identified to subspecies. Thirty-nine (51%) of the color-banded individuals were observed alive at least once after banding. Using program MARK, we estimated that the apparent survival rate (Φ) for all age and sex classes over a 3-mo interval was 87.9 ± 2.0% (±SE) and the annual survival rate was 59.7 ± 5.4%. We found relatively high use of the study areas by peregrines in fall, winter, and spring, and low use in summer. Resighting probabilities (P) were lower in summer compared with other seasons. During fall, winter, and spring, the 3-mo resighting probability (P) was 45.4 ± 7.9% for juveniles, 35.9 ± 5.0% for adult females, and 16.7 ± 4.5% for adult males.

During an irruption of Snowy Owls (Bubo scandiaca) into western Montana in the winter of 2005–2006, we collected dietary data from 42 to 48 owls from three sites. We recorded 5400 prey from 1313 pellets, pellet fragments, and prey remains. Voles represented >90% of the prey from each site. Montane voles (Microtus montanus) dominated at two sites and meadow voles (M. pennsylvanicus) dominated at the third site. Few other prey species were eaten. Food-niche breadth was 1.14, 1.41, 1.92, and dietary evenness was 0.377, 0.398, 0.584 for the three Montana sites. We compared these data to those from six other North American studies reporting 1208 prey items collectively. A random sample of 100 pellets yielded a mean dry mass of 19 g, and a mean length × width of 82 mm × 30 mm, and the number of prey per pellet averaged 5 (SD ± 2). Mean body mass of voles eaten by the owls was 30 g. During the following winter (2006–2007), only three Snowy Owls were found in the same study areas.

We describe morphological measurements, breeding biology, roost-site characteristics, and diet of the endemic and threatened Bearded Screech-Owl (Megascops barbarus) in the central highlands of Chiapas, Mexico. The first nest recorded for this species was in a natural cavity of an old oak (Quercus laurina) and contained a single nestling. Four roosting sites were located, two in Clethra chiapensis (evergreen broadleaf) and two in Pinus ayacahuite (pine; mean height  =  3.4 m). Fecal analysis indicated that diet was primarily insectivorous, consisting of Melononthidae (Coleoptera; 72.3%), along with a few Orthoptera (9.2%), Lepidoptera (3.1%), and Arachnida (1.5%). Data from 39 owls (24 captured and 15 skins) were used for morphology analysis. This species exhibited reversed sexual dimorphism, with females having greater mass and longer tails than males. Molting occurred during the rainy season (July to October), with the primary and secondary feathers being molted simultaneously. Subcutaneous fat was moderate to abundant in the dry season only (December to May). Maximum longevity we recorded was at least 4.17 yr. These first natural history data for the species provides preliminary information for understanding the ecological requirements of the Bearded Screech-Owl in fragmented tropical montane forest.

We studied habitat use for foraging by Swainson's Hawks (Buteo swainsoni) within a complex agricultural crop matrix in California's Central Valley to ascertain if vineyards were used for foraging. Central Valley vineyard agriculture has increased recently, especially in areas supporting the highest regional numbers of Swainson's Hawks. There is concern that increased vineyard coverage may reduce the amount of foraging habitat available for Swainson's Hawks, because vineyards have been considered poor foraging habitat for this species, due to the height and density of the vines. In 2002 and 2003, we conducted road surveys to record observations of foraging Swainson's Hawks in relation to agricultural habitats. Using chi-square tests and 95% CIs, we assessed habitat selection for foraging Swainson's Hawks and determined whether habitat use varied throughout the breeding season. Swainson's Hawks used 10 unique habitat types for foraging during the breeding season. Swainson's Hawks used vineyards less than expected and irrigated hay and dryland grain habitats more than expected, with some variation in habitat use as the season progressed. The variety of habitats that Swainson's Hawks used for foraging in our study area suggests that maintenance of large heterogeneous areas of agricultural habitats that include crops such as alfalfa, as well as large tracts of grazed grasslands, should be one of the priorities for conservation of this species in this region.

Populations of three species of lowland Gyps vultures (G. bengalensis, G. tenuirostris and G. indicus) in South Asia have declined precipitously over the last decade as a result of their feeding on diclofenac-contaminated livestock carcasses. Despite extensive studies on these three species, little is known about population trends in the highland species, Himalayan Vulture (G. himalayensis). We surveyed Himalayan Vultures in Nepal between 2001 and 2006. We found no evidence that their populations are facing the same magnitude of decline or threat as those of the three species of lowland Gyps vultures. We suggest that Himalayan Vultures may not be experiencing the same degree of diclofenac poisoning for a number of reasons, including possibly different foraging behaviors by Himalayan Vultures compared to the other Gyps vultures, and/or relatively lower use of diclofenac in the highland regions.

From 2003–05, we collected the carcasses of 200 dead raptors (of nine species) that had died during rehabilitation at the Beijing Raptor Rescue Center, and analyzed them for the presence of nematode parasites. We observed that a large number of these raptors carried nematode parasites (88 of 200; 44.0% infection rate). In total, we documented the presence of 17 genera of nematodes, belonging to 11 families. The majority of parasites were found in the intestines, followed by the mouth cavity, stomach, and esophagus. The most common nematode parasite was Procyrnea spp. followed by Synhimantus spp., Pseudaprocta spp., Contracaecum spp. and Physaloptera spp. One new species of nematode, Synhimantus (Dispharynx) oti sp. nov. was identified. Furthermore, we documented the first known occurrence of five nematode parasite species in raptors in China.

Condicionamiento Comportamental y Técnicas para Atrapar a Strix Varia

Entrenamos individuos de Strix varia para asociar un silbido o llamado con la provisión de alimento. Esto facilitó enormemente atrapar a las aves, localizar sus nidos y pichones, y reconocer el reemplazo en las parejas reproductivas. Atrapamos 61 lechuzas en un total de 78 veces. Cuarenta y cuatro de las lechuzas habían sido entrenadas antes de su captura. Las trampas bal-chatris (36 capturas) y las redes de niebla colapsables dho-gazas (37 capturas) fueron nuestros métodos preferidos para capturar a las lechuzas. Describimos nuestras técnicas de entrenamiento y de captura como una ayuda para otros estudios sobre S. varia y otras especies de lechuzas, para las cuales sospechamos que éstas técnicas pueden ser aplicables.

Falco tinnunculus es un pequeño halcón de distribución amplia en Eurasia. En China se pueden encontrar dos o tres subespecies de este halcón. Recolectamos muestras de sangre y músculo de 46 individuos en las provincias de Beijing y Shandong. Con base en el análisis de secuencias de la región control del ADN mitocondrial, fueron identificados 12 haplotipos analizando secuencias de 400 pb. Estos haplotipos se dividieron en dos tipos asociados a dos subespecies: F. t. interstinctus y F. t. tinnunculus. Todas las muestras recolectadas en el verano fueron identificadas como F. t. interstinctus y cinco de 13 muestras colectadas durante el invierno correspondieron a F. t. tinnunculus. Estos resultados contrastan la visión típica de que sólo F. t. interstinctus se encuentra en Beijing. Además, encontramos que el patrón de diferenciación genética encontrado es causado por la falta de intercambio genético entre las subespecies; esta ausencia de flujo genético puede ser explicada por la separación espacial de las subespecies durante la época reproductiva.