I used inter-island song playbacks and information on geology, ecology, and behavior to investigate biogeography and species limits in the `Elepaio (Chasiempis sandwichensis), a monarch flycatcher (Monarchidae) endemic to the Hawaiian Islands. `Elepaio occur on Kaua`i, O`ahu, and Hawai`i, but are absent on the four islands of the Maui Nui group in the center of the Hawaiian Archipelago. It is unlikely that `Elepaio became extinct on Maui Nui or were excluded by the presence of competing species. `Elepaio are absent in the fossil record on all four islands of Maui Nui, but occur in the fossil record on all three islands they currently inhabit. They have adapted to a variety of forested habitats and are more resistant to alien diseases than other bird species that have persisted on Maui Nui. `Elepaio on each island responded most strongly to songs from their own island. Response to foreign songs was asymmetrical. Hawai`i `Elepaio responded to songs from Kaua`i, suggesting that `Elepaio on Kaua`i and Hawai`i share a more recent common ancestry. The sequence of colonization events that led to the current distribution was most likely: (1) Kaua`i to O`ahu and (2) Kaua`i to Hawai`i. Geologic and genetic evidence indicate the `Elepaio lineage arrived in the Hawaiian Islands ∼1.5–1.9 million years ago. `Elepaio probably were blown from Kaua`i to Hawai`i during storms, skipping several of the stepping-stones in the Hawaiian chain. The low level of foreign song recognition indicates song could inhibit interbreeding and might serve as an isolating mechanism.

Wood-warblers (Parulidae) have species-specific flight calls given day and night in migration. These vocalizations are believed to maintain flocks and to stimulate migratory activity during migration. However, anecdotal evidence suggests that warblers also give flight calls during non-migratory periods. I examined use of flight calls during the nesting, fledgling, and wintering periods in 23 species of warblers to clarify the seasonal pattern of occurrence for this type of vocalization. Flight calls recorded during migratory and non-migratory periods were similar. The Nashville Warbler (Vermivora ruficapilla) was the only species that gave flight calls during the nesting period and it did so rarely. Half of the species surveyed during fledgling periods and nearly half (47.8%) of the species surveyed during wintering periods gave flight calls. Calls per minute rates during the nesting period were an order of magnitude lower than in the fledgling and wintering periods. Flight calls are most common during migration but this vocalization in warblers is not limited to migratory periods. Flight calls may have functions additional to those during migration.

Bird song has been shown to be important in both inter- and intrasexual selection. Elaboration of the latter trait has been studied extensively. I conducted a field experiment to investigate the role of song in territory establishment of the Prothonotary Warbler (Protonotaria citrea). Songs were recorded for 31 males and song parameters were regressed against dates of territory acquisition, territory size, and territory location. In addition, feeders were placed in the territories of 17 randomly selected males. Song recordings from these males over the entire breeding season were compared with a reference group of 14 males. Males that sang more frequently acquired territories in preferred locations and earlier in the breeding season. A significant change occurred in song rate over the breeding season for males provided supplemental food. These findings suggest that physiological condition constrains song parameters that are important in territory establishment in the Prothonotary Warbler.

We studied parental provisioning rates and nestling body condition in an introgressed population of Golden-winged Warblers (Vermivora chrysoptera) in eastern Ontario. Twelve nests were monitored until the young fledged; six nests were parented by phenotypically pure Golden-winged Warbler males and females, and six were parented by pure Golden-winged Warbler males mated with introgressed hybrid females. Nestlings that had a hybrid parent did not show differences in body condition from nestlings with two Golden-winged Warbler parents. Provisioning patterns were examined for potential relationships with several different factors: gender of the parent (male vs. female), nestling age, pair type (pure vs. hybrid), and the proportion of extra-pair young in the brood. Both males and females increased their provisioning rates as nestlings grew, and males consistently provisioned at higher rates than females. Golden-winged Warbler parents and hybrid parents did not show significant differences in provisioning rates. Females significantly increased provisioning rates with increasing levels of extra-pair paternity. Our results suggest that hybrid nestlings are not at a disadvantage in terms of body condition, and that hybrid parents are equally adept at provisioning their young as are phenotypic Golden-winged Warbler parents.

Information on provisioning behavior of birds in the Indian subcontinent is almost negligible. We studied provisioning of nestlings of the Oriental Magpie-robin (Copsychus saularis) in 11 nests in relation to brood size, nestling age, and time of day during March–July 2006. Both parents fed the nestlings. However, the rate of provisioning trips by females was higher (t = 9.51, df = 10, P < 0.01) than for males. Brood size and time of day did not affect the provisioning rate. Age of nestlings was an important factor affecting rate of parental provisioning. Nestlings were fed more as they became older and there was correlation (Spearman's rho = 1) between parental provisioning trips and nestling age.

We delineate the winter distributions of the five subspecies of Saltmarsh Sharp-tailed (Ammodramus caudacutus) and Nelson's Sharp-tailed (A. nelsoni) sparrows, and comment on patterns of migration. The two subspecies of A. caudacutus (A. c. caudacutus, A. c. diversus) have similar core winter ranges that extend along the Atlantic coast from North Carolina to northeastern Florida. They also occupy two isolated areas within peninsular Florida in Everglades National Park and on the northwest Gulf coast. Migration in A. caudacutus is mainly confined to the coast. The subspecies of A. nelsoni (A. n. nelsoni, A. n. alterus, A. n. subvirgatus) occupy different but overlapping winter ranges. A. n. nelsoni is the most widespread, occurring from North Carolina to Texas. Some birds migrate along the Atlantic coast southwards in fall, and others follow interior routes through the Mississippi River watershed in both fall and spring. We suggest A. n. nelsoni wintering along the Atlantic coast in spring fly directly inland towards their northern breeding areas. Some birds in fall also approach the southeastern coastline directly across the Appalachian Mountains. A. n. alterus mainly winters along the southeastern Atlantic coast to Florida, and in fewer numbers along the Gulf coast at least to Louisiana. Some A. n. alterus may migrate to the Gulf coast directly via inland routes west of the Appalachian Mountains. A. n. subvirgatus has the most limited wintering distribution, from South Carolina to northeast Florida, and is strictly a coastal migrant south of New England. Limited wintering ranges and narrow winter habitat requirements place continental populations of sharp-tailed sparrows at risk.

Conservation of threatened species requires knowledge of individual movements within and among spatially distinct subpopulations. We quantified philopatry, local dispersal, and number of breeding sites used by 62 Western Snowy Plovers (Charadrius alexandrinus nivosus) that were marked as chicks and returned to a breeding area in coastal northern California. Slightly more males (17%) than females (12%) returned to the study area. Natal dispersal (distance between natal nest and first nest as a yearling) was similar for males and females, and greater than reported for other shorebirds. Philopatric plovers dispersed shorter distances between successive nests within a breeding season compared to the distance between successive nests from one year to the next. Most males and females that bred locally wintered in the study area. Those that wintered locally tended to be from later clutches compared to the few migrants that hatched earlier in the season. The population of Snowy Plovers in coastal northern California is linked by dispersal with other breeding plovers along the Pacific coast. Dispersal estimates indicate that wide-ranging movements are typical of Snowy Plovers throughout their range, which should facilitate recolonization of habitats.

We examined growth rates and physical development of four body characteristics (mass, wing chord, bill length, and head width) of Lesser Prairie-chickens (Tympanuchus pallidicinctus) 3 to 111 days post-hatch in southeastern New Mexico. Growth rates, inflection points, and selected growth curves (logistic and Gompertz) associated with body mass and wing chord were similar between Lesser Prairie-chickens in New Mexico and Kansas. The asymptotic body mass (713 ± 7 g) was less for female and male yearling Lesser Prairie-chickens in New Mexico than for either yearling females or males in Kansas (male: 789 ± 4, female: 719 ± 6). Juvenile Lesser Prairie-chickens in New Mexico achieved 90% of their asymptotic body mass 7 days faster than Lesser Prairie-chickens in Kansas.

We examined abiotic and biotic variables potentially associated with Northern Bobwhite (Colinus virginianus) nest-site selection and nest success in southern Texas, USA during 2002–2005. These data were used to characterize bobwhite nest-site selection, and to develop and evaluate models of daily nest survival in Program MARK. Nest sites (n = 123) had greater visual obscurity (3.50 vs. 2.60 dm) and vegetation height (64 vs. 47 cm), and less bare ground (11 vs. 25%) compared to random locations (n = 123). The two best models indicated daily nest survival increased with increasing mean maximum temperature and increasing cumulative precipitation. The model-averaged (± SE) estimate for bobwhite daily nest survival was 0.9593 ± 0.0060. These results suggest that bobwhites selected for a specific range of nest-site microhabitat attributes, but that nest predation was largely random. Bobwhite nest survival and productivity in semiarid, subtropical, southern Texas may be largely dependent on weather factors (e.g., temperature and precipitation).

I assessed changes in bird distributions associated with alteration of riparian willow (Salix spp.) habitat by supplementally-fed elk (Cervus elaphus nelsoni) in western Wyoming, USA. Bird communities in stands close to (n = 4) and distant from (n = 4) feeding stations were dissimilar (complement of the Morisita-Horn index = 0.27). Stands close to feeding stations had lower species richness and relative abundances of all birds while relative abundances of all shrub-steppe species were greater, an effect of elk-induced conversion of willow to shrub-steppe habitat. Elk affected habitat mainly by reducing willow cover <2 m in height. Reductions in willow cover at >0.5–1 and >1–2 m, relative to 11 alternative variables, were responsible for declines in Willow Flycatchers (Empidonax traillii), MacGillivray's Warblers (Oporornis tolmiei), and Fox Sparrows (Passerella iliaca). Elk feeding in the Gros Ventre River Valley had reduced but similar effects on birds and habitat despite a smaller number of elk fed (1,900 vs. 9,200 annually for 1994–1998) and a shorter duration of feeding (initiation in 1960 vs. 1912) relative to the National Elk Refuge. These effects can extend at least 1.5 km.

We surveyed birds during breeding, migratory, and wintering seasons in forest patches of two fragmented landscapes in the Valley and Ridge Province of south-central Pennsylvania during 1994–1996. Our objective was to examine presence of species in relation to forest-patch size (<2, 6–20, 40–150, and >1,500 ha) and extent of regional fragmentation. Several species, particularly long-distance migrants (e.g., Eastern Wood-pewee [Contopus virens], Red-eyed Vireo [Vireo olivaceus], Wood Thrush [Hylocichla mustelina], Worm-eating Warbler [Helmitheros vermivorum], and Scarlet Tanager [Piranga olivacea]), were more likely to occur in larger forest patches than in smaller patches during the breeding and spring-migratory seasons. Short-distance migrants (e.g., American Robin [Turdus migratorius], Gray Catbird [Dumetella carolinensis], and Eastern Towhee [Pipilo erythrophthalmus]), responded to fragmentation at a regional scale and were more commonly encountered in the more fragmented landscape, particularly during migratory periods. Species observed during fall migration were not influenced by patch size. The Pileated Woodpecker (Dryocopus pileatus) responded positively to patch size in all seasons, whereas the Song Sparrow (Melospiza melodia) was influenced negatively by patch size in three of four seasons. More research should be conducted at sites during winter and migration to corroborate these results and to examine the role patch size may have in long-term survivorship of migratory birds.

Seasonal fruits are an important food resource for small songbirds during autumn migration in southern New England. Therefore, conservation and management of important stopover sites used by migrating birds requires knowledge about nutritional requirements of songbirds and nutritional composition of commonly consumed fruits. We measured nutrient composition and energy density of nine common fruits on Block Island, Rhode Island, and conducted a field experiment to estimate consumption rates of three of these fruits by birds during autumn migration. Most common fruits on Block Island contained primarily carbohydrates (41.3–91.2% dry weight), and little protein (2.6–8.6%) and fat (0.9–3.7%), although three contained more fat: Myrica pennsylvanica (50.3%), Viburnum dentatum (41.3%), and Parthenocissus quinquefolia (23.6%). Bird consumption of high-fat, high-energy V. dentatum fruit and high-carbohydrate, low-energy Phytolacca americana fruit was greater than consumption of Aronia melanocarpa, a high-carbohydrate, low-energy fruit. We estimated that migratory birds on Block Island must eat up to four times their body mass in fruit wet weight each day to satisfy their energy requirements when eating low-energy fruits such as P. americana, and they cannot satisfy their protein requirements when eating only certain high-energy fruits such as V. dentatum. Our results suggest that many migratory birds must eat both fruits and insects to meet their dietary needs. Thus, shrubland habitat at important migratory stopover sites such as Block Island should be managed so that it contains a variety of preferred fruit-bearing shrubs and an adequate abundance of insects.

We compared the feeding choices of an invasive frugivore, the European Starling (Sturnus vulgaris), with those of a native, the American Robin (Turdus migratorius). Using captive birds, we tested whether these species differ in their preferences when offered a choice between a native and an invasive fruit, and between a novel and a familiar food. We examined willingness to eat fruits of selected invasive plants and to select a novel food by measuring the time elapsed before feeding began. Both species demonstrated significant preferences for invasive fruits over similar native fruits in two of three choice tests. Both starlings and robins ate autumn olive (Elaeagnus umbellata) fruits significantly more willingly than Asiatic bittersweet (Celastrus orbiculatus). Starlings, but not robins when choosing between a novel and a familiar food, strongly preferred the familiar food. We found no differences in willingness of birds to eat a novel food when it was the only food available. These results suggest that some fleshy-fruited invasive plants may receive more dispersal services than native plants with similar fruits, and that different frugivores may be seed dispersers for different invasive plants.

Flooded forests represent an important part of Amazonian diversity, yet the distribution, ecology, and evolutionary history of the avifauna of these forests have received little attention. We conducted ornithological surveys in the Rio Branco Basin, which is entirely in the Brazilian State of Roraima. In this paper, we discuss the presence of 20 bird species recorded along the lower Rio Branco, 16 of which represent new records for the State of Roraima and the entire Rio Branco Basin. Among our most interesting records are four species of white-water river specialists (Synallaxis propinqua, Stigmatura napensis, Serpophaga hypoleuca, and Conirostrum bicolor) that have populations on the lower Rio Branco, isolated from other Amazonian white-water river systems by the black waters of the Rio Negro where they do not occur. We also discovered new localities for the endemic and endangered Rio Branco Antbird (Cercomacra carbonaria), doubling the size of its known range. We discuss the implications of these records in a biogeographic perspective for better understanding the distributional patterns of the flooded-forest avifauna in Amazonia.

The Black-faced Hawk (Leucopternis melanops) and White-browed Hawk (L. kuhli) are forest-based, Amazonian raptors whose distributions have been considered to be mutually exclusive north and south of the Amazon River, respectively. The occurrence of L. melanops south of the river was first indicated by a specimen collected by A. M. Olalla on the lower Tapajós River >70 years ago. The provenience of this specimen has been contested by diverse authors but both species were recently captured at localities along the lower Tapajós, corroborating the coexistence of L. melanops and L. kuhli in this region. We present four new specimen localities for L. melanops in southern Amazonia, greatly amplifying its known distribution. We also describe the immature plumage of L. kuhli based on three specimens that had been identified as L. melanops.

We describe the first recordings of a male vocalization of the Turquoise Cotinga (Cotinga ridgwayi) along with reviewing the sound production in the genus Cotinga. Vocalizations were heard in the Coto Brus region of southwestern Costa Rica from late 2003 until early 2005. The vocalization described is different from previous calls known for the species and genus. The vocalization is a pure tone, produced at a high frequency. These vocalizations were observed in a variety of contexts, although more often during alarm or advertisement situations.

I describe the nesting behavior of the Pavonine Quetzal (Pharomachrus pavoninus) at Los Amigos in the southeastern Peruvian Amazon. I found a single nest cavity 4.2 m above ground in a dead snag in terra firme forest. The cavity contained two pale blue eggs each with a few small brown-buff speckles, of which one hatched. I observed incubation between 18 February and 2 March 2004. Based on an average of 0.7 observation hrs/day, the male appeared to incubate during most of the day from at least 0950 hrs until sunset (near 1745 hrs) when the pair would switch before nightfall. The female appeared to incubate at night and during the early morning. Fifty-six percent of 32 food deliveries observed between 6 and 26 March were tree frogs and 44% were fruits. The nestling fledged on 26 March, 20 days after the first observed food provisioning. The nestling period is estimated to be 21–24 days. The plumage development of the nestling, vocalizations, and other observations are discussed and compared with the Resplendent Quetzal (Pharomachrus mocinno).

We studied sexual pair behavior and cuckoldry of nine female and five male Reed Buntings (Emberiza schoeniclus) in a large outdoor aviary. Three males established small territories and paired with females. We observed 23 copulation attempts with identified partners during a period of approximately 6 weeks, 10 between social mates, 12 between unpaired females and paired males (extrapair for males), and one between a paired female and a paired male which was not the social mate (extrapair for both). Both males and females initiated copulation attempts which, in most cases, were preceded by precopulatory displays. No forced copulations were observed and females appeared to have an active role in mating behavior.

We monitored nesting home ranges of White-winged Doves (Zenaida asiatica) in Waco, Texas using field-implanted, subcutaneous radio transmitters. Mean nesting home-range size differed by gender (75.7 km² for females, 31.9 km² for males, P = 0.17). Mean nesting home-range for all individuals of known gender differed by year (75.6 km² for 2002, 32.0 km² for 2003, P < 0.001). Within-year mean nesting home ranges for individuals differed by gender for 2002 but did not for 2003. We received reports of 35 band recoveries (2.3% of those banded) through March 2004. Distance moved did not differ by year, gender for adults, or for gender by age. Distances of recoveries from banding sites ranged from 0 to 477.4 km.

Eurasian Collared-doves (Streptopelia decaocto) have colonized small rural towns throughout Colorado. We document their occurrence in 23 towns in Weld and Larimer counties in northeastern Colorado during the 2004 breeding season. Estimated population sizes in these towns ranged from 0 to 154 birds. Population increases were detected in 17 towns across the 2-month breeding season (Jun–Aug) with these increases ranging from 1.1- to 6.9-fold. We interpret these data as indicating successful breeding and expanding populations. These are the first reliable data on population sizes of Eurasian Collared-dove in North America and may benefit management strategies for this invasive species in Colorado and elsewhere in the Great Plains.

We quantified the diet of the Rufous-legged Owl (Strix rufipes) by analysing 63 pellets collected during 2003 and 2005 in a small coastal sclerophyllous forest stand at the northern limit of its distribution in Chile (31–32° S). The diet comprised small mammals (frequency = 57.8%, biomass = 99.3%), crustaceans (frequency = 1.7%, biomass = 0.1%), and insects (frequency = 40.5%, biomass = 0.6%). We identified at least 10 small mammal species in these pellets of which Bennett's chinchilla rat (Abrocoma bennetti; frequency = 12.4%) and long-tailed pygmy rice rat (Oligoryzomys longicaudatus; frequency = 7.4%) were the most frequently occurring mammalian prey remains. Terrestrial small mammals accounted for 21.5% by frequency of all individuals and 49.1% of the total biomass; scansorial/arboreal small mammals accounted for only 13.2% of all individual prey and 17.2% of total biomass.

We studied spatial differences in Barn Owl (Tyto alba stertens) diets in agroecosystems of six districts of central Punjab, Pakistan. Analysis of pellets collected over 3 years revealed the house shrew (Suncus murinus) dominated all diets. This species constituted 75.0% of the diet in the Sheikhupura District, 68.4% in the Okara District, 67.2% in the Faisalabad District, 65.6% in the Toba Tek Singh District, 59.3% in the Jhang District, and 56.3% in the Hafizabad District. Rats and mice together formed 28% of the overall diet while birds (4.2%) were consumed more than bats (2.0%). The greatest diversity in Barn Owl diets was in the Jhang District.

Examination of 193 whole pellets and a number of partial pellets of a pair of Barn Owls (Tyto alba) in Neve Shiret, a neighborhood of Tel Aviv, Israel during the 2005 and 2006 breeding seasons revealed a total of 711 prey specimens. Six species of small mammals comprised 99.3% of the diet with a frequency of occurrence of 100% in pellets. Levant voles (Microtus socialis guentheri) (48.1%) and house mice (Mus musculus) (32.9%) were the most common prey species. The Barn Owl pair hunted in croplands adjacent to an urban residential area.

Red-headed Woodpeckers (Melanerpes erythrocephalus) occasionally usurp nests of other species. I compared incidence of nest usurpation in logged and non-logged treatments in a burned ponderosa pine (Pinus ponderosa) forest in 2004 and 2005. I predicted that usurpation would occur more often on logged than non-logged sites because Red-headed Woodpeckers tend to nest in more open habitats. Red-headed Woodpeckers nested more often and usurped a greater proportion of host species in logged (n = 6) than non-logged (n = 3) areas, despite host cavities being more abundant on the non-logged treatment. Usurping Red-headed Woodpecker pairs initiated nesting earlier (x̄ = 12 May ± 2 days) than pairs that excavated cavities (18 May ± 2 days) which implies an existing benefit to offset the cost of interspecific conflict.

There is scant information on whether Wood Thrushes (Hylocichla mustelina) are present at nests when Brown-headed Cowbirds (Molothrus ater) come to lay their eggs. We used miniature digital video cameras to document 10 visitations by cowbirds to five Wood Thrush nests. Cowbirds visited Wood Thrush nests on six occasions when host females were absent and aggressively approached incubating females on four other visits. Parental nest defense did not appear to be an effective deterrent to a challenge by a cowbird. Wood Thrushes were more tolerant of cameras early in the nesting season than after mid-June when they were more likely to accept the presence of cameras if they were gradually moved closer to nests over a period of several days.

We studied the effects of habitat fragmentation on productivity of Yellow-breasted Chat (Icteria virens) and Gray Catbird (Dumetella carolinensis) in southern British Columbia in a western riparian ecosystem. Nesting dates were later in isolated habitat patches than in continuous habitat patches for both species. We found no direct evidence that habitat fragmentation decreased productivity in either species. Average fecundity did not significantly differ between continuous (2.54 fledglings for Gray Catbird; 1.78 and 1.67 fledglings for Yellow-breasted Chat in 2002 and 2003, respectively) and isolated sites (1.33 fledglings for Gray Catbird; 1.78 and 0.87 fledglings for Yellow-breasted Chat in 2002 and 2003, respectively). Territory size, as measured by mapping perch locations for breeding adults, was smaller for Yellow-breasted Chats breeding in the Okanagan Valley (0.25 ha) than for chats in mid and high-density southern populations. However, overall fecundity and nest success were similar to more southerly populations. These results suggest that both species can persist in a relatively fragmented ecosystem.

Polygyny occasionally occurs in passerine species that are generally socially monogamous. We document the second case of polygynous mating in the Gray Catbird (Dumetella carolinensis) and provide the first detailed account of this behavior. Daily provisioning rates of the polygynous male documented this male provisioned one nest more than the other (5.9 ± 2.2 trips/hr vs. 1.7 ± 1.1 trips/hr). The difference between the male's provisioning rates diminished when standardized for the number of chicks per nest. Polygyny appears to be an alternative mating strategy for the Gray Catbird in certain situations.

Macaroni (Eudyptes chrysolophus) and Southern Rockhopper penguins (E. c. chrysocome) have been classified as Vulnerable due to decreasing populations in recent decades. We report on a survey of Isla Recalada, Chile, a site described historically as containing an estimated population of 10,013 (±570) Rockhopper and 559 Macaroni penguins. Our survey was conducted on 14 and 15 November 2005 to coincide with peak colony attendance. No Rockhopper or Macaroni penguins were observed on Isla Recalada during this period. This survey suggests the population of these penguins has dispersed due to possible anthropogenic pressures or climate variation, and that both species of penguins have been extirpated from Isla Recalada.

Artificial lights can have detrimental effects on nocturnal migrant birds and other wildlife, yet some species of typically diurnal insectivorous birds are capable of foraging at night under artificial illumination. Here, we report observations of at least 15 wood-warbler species (Parulidae), one tyrant-flycatcher (Tyrannidae), and one mimid (Mimidae) foraging at night in areas illuminated by powerful artificial lights. To our knowledge, our observations represent the first report of a mixed-species flock of birds foraging on insects attracted to artificial lights or within foliage illuminated by artificial lights at night.

Yellow-throated (Vireo flavifrons) and Red-eyed vireos (V. olivaceus) were observed feeding on green anoles (Anolis carolinensis carolinensis) at two localities in Florida and one in South Carolina. Vireos are long-distance migrants that require foods high in fatty acid content, especially when engaging in migration. It is not unlikely that vireos have an opportunistic foraging strategy to obtain the necessary food requirements, including attacking and consuming prey items such as small lizards. This note provides the first published reports of lizards taken as prey by these two species.