Few studies have quantified parental care patterns and diets of Mississippi Kites (Ictinia mississippiensis). Using video-recording systems, we quantified and analyzed nesting Mississippi Kite parental care and food delivery in eastern Arkansas. During the incubation period, male kites appeared to spend more time (  =  311.8 min/day, SE  =  30.27) on the nest than females (  =  249.6 min/day, SE  =  30.62), though the difference was not statistically significant. Females spent significantly more time on the nest during the brooding period than did males. Female kites also spent significantly more time shading nestlings than males. The amount of time that females stayed on the nest overnight during the incubation (  =  886 min/night) and brooding periods (  =  815 min/night) was longer than that of males (  =  806 and 739 min/night, respectively). Male kites delivered more food items (58%) than females (42%) and also delivered significantly more vertebrate food items than did females. Insects were the most common type of food items (80%) delivered to nests. Vertebrates made up 5% of the food items, and the remaining 15% could not be identified. Our data indicated differential sex-division in parental contributions by male and female Mississippi Kites, but a similar contribution in terms of overall parental effort.

Blood and feathers of Bald Eagles (Haliaeetus leucocephalus) banded as nestlings (n  =  17), captured as free-flying (n  =  91), or submitted for rehabilitation (n  =  29) in southwestern Montana between December 2005 and April 2008 were sampled for mercury (Hg), selenium (Se), lead (Pb), seven other trace elements, and organochlorines. Hg concentrations in blood (hereafter “HgB”) did not differ between captured eagles and those submitted for rehabilitation, and HgB in both were higher than concentrations in nestlings (P < 0.01). Se concentrations in blood (“SeB”) were similar among groups. Pb concentrations in blood (“PbB”) were higher in captured eagles than in those submitted for rehabilitation (P  =  0.05). No bird submitted for rehabilitation exhibited toxic levels of PbB, but 9% of captured eagles did. HgB and PbB in captured eagles declined as date of capture advanced from autumn to spring. Hg and Se concentrations in feathers (“HgF”; “SeF”) tended to increase with age-class. HgB and SeB, and HgB and HgF were correlated in nestlings and captured eagles (P < 0.05) but not in birds submitted for rehabilitation. Birds captured in autumn during this study had higher HgB (P < 0.05) than birds captured in autumn in the early 1990s, but SeB did not differ. HgB and SeB in birds captured in spring during this study were similar to those of birds captured in spring in the early 1990s, but PbB was lower. Five eagles were recaptured and resampled for contaminants up to 18 yr after initial banding and sampling but no time-trends were detected in contaminant concentrations due to small sample size. Other trace elements and organochlorines if detected in blood were at very low concentrations.

Adjacent nesting home ranges of four radio-tagged Southern Boobooks (Ninox novaeseelandiae) were studied in a Canberra, Australia, woodland over 418 observation nights during four breeding seasons. Spatial locations and bouts of territorial calling (“boobook calls”) were recorded during each observation night. Home ranges and core areas were computed from the spatial locations using minimum convex polygons and characteristic hull polygons. Home-range sizes varied by individual owl, between breeding seasons, and by estimation method, ranging from 18.1 to 205.8 ha. Core-area estimates varied from 0.2 ha to 19.6 ha, indicating intensive use of core areas within much larger home ranges. Overall, about 26% of the boobooks' vocalizations occurred within core areas and about 56% within the home range but outside the core area, often near the border shared with the adjacent pair. Approximately 21% of boobook calls were observed on or outside home-range boundaries, which suggested that owls actively defended areas larger than their core areas.

Statewide distribution and habitat use of the Florida Burrowing Owl (Athene cunicularia floridana), currently state-listed as a “Species of Special Concern,” is not well-understood, particularly in remote, nonurban areas. Its status as a protected species is currently being reevaluated and information is needed to help state wildlife managers better understand habitat usage in nonurban areas. To help address this need, we visited Burrowing Owl sites from historical databases to verify and update them while also documenting new locations. We quantified land cover within empirically-derived distances around burrows with confirmed or probable breeding activity, then compared observed and available proportions of habitat, calculated selection indices, and determined selection/avoidance for each land-cover class. These empirical results were used in combination with literature review and field observations to select land-cover criteria for suitable habitat. The final results appear to correlate well with the overall distribution of known nonurban Burrowing Owl records, and demonstrate that a substantial amount of potentially suitable breeding habitat exists throughout Florida's central interior, but only a small proportion of it occurs inside conservation-managed areas. Improved pasture, the most prevalent land-cover class, was the most strongly selected in our study and may be of high importance to nonurban breeding Burrowing Owls. These results may assist wildlife managers in both management actions and species status decisions. We recommend increasing surveys and conservation efforts in nonurban areas and enhancing cooperation with landowners, particularly ranchers, as success on private lands seems crucial to the long-term persistence of this species in Florida.

We conducted intensive helicopter-supported surveys to assess the distribution, occupancy, and reproductive rate of Peregrine Falcons (Falco peregrinus anatum) in the Yukon-Tanana uplands of interior Alaska 1995–2003. We surveyed specific reaches of Birch Creek and the Goodpaster and Salcha rivers in this remote area to monitor this nesting species. Each year, we visited potential cliff-nesting areas and known nesting territories during early incubation (late May) to assess occupancy and nesting activities, and during the late-nestling period (mid-July) to count young, document nesting success, and measure reproductive rate. We identified 55 different nest cliffs occupied by Peregrine Falcons during at least one year of our survey. The number of occupied nesting territories detected each year increased from a low of 12 in 1995 to a high of 38 in 2002. Reproductive rate averaged 1.6 young/occupied territory and 2.4 young/successful territory for the nine-year period. The percentage of successful territories each year ranged from 42% to 81% (mean  =  65%). Little is known about Peregrine Falcon numbers and distribution in the Yukon-Tanana uplands prior to the DDT-induced decline, but they are currently the most abundant cliff-nesting raptor in the region. Monitoring these remote areas may provide a valuable tool to alert us to population declines before they occur in larger drainages.

Between 1979 and 2006, we captured 452 Sharp-shinned Hawks (Accipiter striatus) at the Palomarin Field Station in the Point Reyes National Seashore, Marin County, central coastal California. Of all captures, the majority, 83%, were young males. We recaptured 46 individuals; 42 were originally banded at our site, and four were originally banded at a site 24 km southeast of our banding site, suggesting that our site may be a point on migration or a wintering destination for some Sharp-shinned Hawks. We captured Sharp-shinned Hawks during every month of the year, with peak captures occurring in the fall from late September to mid-November. Capture rate significantly increased over the course of our study, consistent with results from some other monitoring programs.

We studied foraging habitat use and selection of the Western Marsh-Harrier (Circus aeruginosus) in agricultural areas, by radio-tracking seven individuals in the Ebro Basin (northern Iberian Peninsula). Generalized Linear Mixed Models indicated that the probability that a certain point within the study area was used by harriers was influenced by both distance to the nesting site and habitat. Probability of occurrence decreased with the distance to the nesting site and increased in wetlands and herbaceous crops (both those with high-intensity agricultural practices and those with low-intensity agriculture). In areas dominated by high-intensity herbaceous crops (irrigated maize, cereal, and alfalfa), marsh-harriers (n  =  2) did not use all crop types equally throughout the year; they selected different crops in relation to the crop stage (growing, fallow, and stubble) and to particular agricultural practices (irrigated, unirrigated).

The diets of Little Owls (Athene noctua) and Long-eared Owls (Asio otus) have been studied extensively, although seldom in desert habitats where they coexist. We compared diets of these two species near the Minqin Desert Experimental Research Station in northwestern China. Diets differed significantly by frequency: Little Owls fed mainly on mammals (56%) and beetles (42%), and Long-eared Owls fed almost exclusively on mammals (97%). Dietary overlap was 0.62. Diets differed significantly in four dimensions: prey size, feeding time, feeding habitat, and prey mass, and the overlaps for these dimensions were less than 0.74. However, at the generic level for mammals, the difference was not significant, and dietary overlap was 0.97, indicating that they fed on similar mammal assemblages. The overlap for presumed feeding time and habitat was almost complete for mammals. However, owls consumed mammals of different size; overlap of mammal size was 0.74. Our results indicate that although the roost sites of the two owl species were in close proximity and the main prey species overlapped extensively, the owls coexisted mainly by consuming prey of different size.