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We document 26 incidents of sunning behavior in 5 species of Accipitridae, including Crested Eagle (Morphnus guianensis), Black Hawk-Eagle (Spizaetus tyrannus), Ornate Hawk-Eagle (Spizaetus ornatus), Roadside Hawk (Rupornis magnirostris), and White Hawk (Pseudastur albicollis), during a camera-trap survey conducted in Madre de Dios, Peru, in 2014. The sunning behavior was observed in forest clearings along logging trails and on a dirt road. We recorded 2 high-intensity sunning postures: "full-spreadeagle," in which the bird lies horizontally on the ground with wings outstretched, tail fanned, and head somewhat raised; and "full-spread," in which the bird stands while holding its wings out at right angles to the body. Sunning is a maintenance behavior observed in many bird species and has been reported in Accipitriformes in various habitats, but it is not commonly observed in tropical rainforests because of low visibility. Our camera traps recorded sunning behavior from 0931 h to 1400 h, a period in which ambient temperature increased until reaching its maximum around 1400 h. The most likely function of sunning in Accipitriformes in the rainforest is an anti-ectoparasite strategy. Camera-trap monitoring has been useful in detecting unusual interactions and diel patterns of activity, and researchers can obtain a wide range of natural history, ecological, and behavioral insights that would be difficult to obtain using traditional methods. We recommend analyzing "bycatch" data from camera traps to recover information about bird behaviors that would otherwise be unattainable. [ABSTRACT FROM AUTHOR]

Changes in vegetation structure and species composition affect habitat use and behavior in most bird species by altering the distribution and abundance of their resources. We explore how the mating and foraging behavior of Cassin's Kingbirds (Tyrannus vociferans) varies by habitat type within a 2,450 ha urban park in Mexico City. The study site includes primarily water bodies, riparian vegetation, willow and Montezuma cypress stands, maize fields, and grasslands. We recorded kingbird behavior twice a week along 21 transects throughout 2012 and 2015. Courtship and reproductive behaviors were displayed in autumn (Sep) and early winter (Dec). Intraspecific agonistic behaviors were associated with courtship and mating events, particularly in 2015. Cassin's Kingbird generally favored open vegetation. The main foraging strategy in open habitats was flycatching but foliage gleaning became frequent when mistletoe plants produced fruits in infested willow stands. The use of mistletoe fruits, presumably a secondary diet item, coincided with the breeding season. In addition to these observations, our study is the first report of Cassin's Kingbird winter mating at low latitudes. [ABSTRACT FROM AUTHOR]

Nomadism is a type of movement lacking fixed spatiotemporal patterns, evident in species inhabiting variable environments. The irregular movement characterizing nomadic species often acts as a challenging barrier for scientists investigating their ecology. We provide an insight on the movement of a nomadic desert bird, the Spotted Sandgrouse (Pterocles senegallus), within and between different activity seasons. The data were obtained from 1 individual fitted with a satellite transmitter, which was tracked for ∼2.5 years. Three main activity seasons were detected during which the bird stayed in a specific area: pre-breeding, breeding, and winter. Nomadic behavior was evident during the pre-breeding and breeding seasons, whereas site fidelity was observed during winter (i.e., seasonal nomadism). Local scale fidelity with respect to roosting behavior was also evident among and within the 3 winters of tracking. Field observations carried out during the first breeding season enabled us to link the movement patterns of the bird with its behavior at different phases of the breeding season. Within and between activity seasons, the bird was engaged in short- and long-distance scouting forays. The long-distance ones occurred only during the pre-breeding season. In some of the scouting forays, the bird arrived at sites it had previously utilized, suggesting the existence of spatial memory and navigation capability. This fine-scale description of movement can uncover key features, which allow the survival and reproduction of nomadic birds inhabiting arid areas where the distribution of resources is largely unpredictable. [ABSTRACT FROM AUTHOR]

Hybridization events have long interested biologists because of their implications for species concepts and taxonomy. Documenting hybridization events is important because hybridization rates are commonly used as support for accepted taxonomic divisions. In July 2017, we observed a nest where a male Cerulean Warbler (Setophaga cerulea) and a female Blackthroated Blue Warbler (Setophaga caerulescens) were feeding nestlings. The Cerulean Warbler and Blackthroated Blue Warbler communicated with each other using song (male) and calls (female), similar to a nonhybrid pair of either parent species, and the pair was not observed to engage in aggressive behaviors toward each other. Interestingly, the Black-throated Blue Warbler is not known to breed in Indiana, although it is a regular migrant in the spring and fall. We describe the behaviors of the hybrid pair at the nest, provide photographs and audio recordings for documentation, and hypothesize that this instance of hybrid pairing may have occurred due to mate scarcity. [ABSTRACT FROM AUTHOR]

Nestlings of some aerial insectivores experience pre-fledging mass recession, possibly to achieve optimum wing loading at fledging. However, studies to date where mass recession was linked to wing loading at fledging have been limited to 2 species of swifts (Apodidae), and additional studies are needed to determine if factors contributing to prefledging mass recession vary among species. We examined factors contributing to pre-fledging mass recession by nestling Tree Swallows (Tachycineta bicolor). During the 2015 breeding season in Kentucky, nestling Tree Swallows in 29 broods were divided into half-weighted, full-weighted, and control treatment groups. Lead weights weighing either 2.5% (0.6 g) or 5% (1.2 g) of nestling mass were glued to the back feathers of half-weighted and full-weighted nestlings, respectively, between 9 and 11 days post-hatching. Video recordings were used to monitor provisioning and begging behavior. Treatment groups did not differ in mass at fledging, amount of mass lost, or wing loading at fledging, and adult provisioning rates and time spent begging by nestlings did not vary from day 11 to day 19 post-hatching. Thus, mass loss by nestling Tree Swallows prior to fledging was not due to changes in either parental or nestling behavior, but likely resulted from loss of water from maturing feathers and other tissues. In contrast, studies of 2 species of swifts (Apodidae) revealed that changes in nestling behavior influenced pre-fledging mass recession, with weighted nestlings losing more mass than control nestlings, apparently to optimize wing loading at fledging. This difference between swifts and Tree Swallows may be due to differences in the duration of nestling periods (longer for swifts) and wing loading (higher in swifts). With greater wing loading, optimum mass at fledging may be more critical for swifts than Tree Swallows. [ABSTRACT FROM AUTHOR]

Stopover sites are essential to bird migration between wintering and breeding grounds, but annual variation in use and habitat conditions make it difficult to determine which sites are most critical for conservation. By studying physiological factors that may influence a bird’s behavior when choosing and using a stopover site, researchers can target certain species or locations and more efficiently invest in conservation efforts. In spring 2013 and 2014, we studied stopover refueling performance in a common northeastern spring migrant, the White-throated Sparrow (Zonotrichia albicollis), at 2 locations near the south shore of Lake Ontario. We used morphological measurements and physiological techniques that assessed the concentration of the blood metabolite plasma triglyceride as a measure of fat deposition and feeding efficiency. We found that birds captured at an inland location had a significantly higher body condition score than birds captured at a coastal stopover site within 0.5 km of the shore; a trend toward higher triglyceride concentrations was also noted at the inland location. We found no significant differences in triglyceride concentrations between White-throated Sparrow color morphs, in contrast to previous studies performed during fall migration. Our results suggest that spring migrants arriving in the area in good energetic condition may begin their cross-lake journey directly from the inland site, while birds in poorer condition may ‘‘pile up’’ at the lakeshore and then compete with other migrants for available resources, slowing their fat deposition rate. Our results also reinforce the importance of protecting high-quality stopover habitat where birds congregate near geographic barriers but suggest that inland habitat patches are important stopover sites that may allow some migrants to bypass nearshore areas of intense competition. [ABSTRACT FROM AUTHOR]

The Gray Vireo (Vireo vicinior) is currently listed as threatened in New Mexico (USA), and detailed observations of its breeding behavior are limited. Like other vireos, the Gray Vireo builds a woven-cup nest of grasses and adhesive materials such as plant fibers and spider webs. However, no other vireo has been documented crushing, spreading, and incorporating berries into nests. We observed female Gray Vireos (n = 7) crushing and spreading one-seed juniper (Juniperus monosperma) berries over forked tree branches and then marking them with a blade of grass or spider web. Gray Vireos may be using the juniper berries for the potential anti-microbial properties of juniper berry oil described for other species of juniper. [ABSTRACT FROM AUTHOR]

Interspecific feeding has been recorded for many bird species worldwide, especially in Europe, yet little information is available on interspecific feeding in China. Here we report a first sighting of an interspecific feeding case between a Rufous-bellied Niltava (Niltava sundara) and a Snowy-browed Flycatcher (Ficedula hyperythra) observed in the Ailao Mountains in Yunnan Province. According to the images and films captured by a camera trap, a male Snowy-browed Flycatcher was found serving as a helper at the nest of a Rufous-bellied Niltava on 17 June 2017. The helping behavior lasted for at least 2 d. The Rufous-bellied Niltava parents showed no aggression when the helper approached their nestlings. We cannot determine the causes of the reported interspecific feeding of the nestlings because the prior history of any of adults involved is unclear. The Rufous-bellied Niltava nestlings’ begging behavior might have stimulated the interspecific feeding by the male Snowy-browed Flycatcher. [ABSTRACT FROM AUTHOR]

Other than penguins, only one bird species—the White-winged Diuca Finch (Idiopsar speculifera)—is known to nest directly on ice. Here we provide new details on this unique behavior, as well as the first description of a White-fronted Ground-Tyrant (Muscisaxicola albifrons) nest, from the Quelccaya Ice Cap, in the Cordillera Vilcanota of Peru. Since 2005, >50 old White-winged Diuca Finch nests have been found. The first 2 active nests were found in April 2014; 9 were found in April 2016, 1 of which was filmed for 10 d during the 2016 nestling period. Video of the nest revealed infrequent feedings (>1 h between visits), slow nestling development (estimated 20–30 d), and feeding via regurgitation. The first and only active White-fronted Ground-Tyrant nest was found in October 2014, beneath the glacier in the same area. Three other unoccupied White-fronted Ground-Tyrant nests and an eggshell have been found since, all on glacier ice. At Quelccaya, we also observed multiple species roosting in crevasses or voids (caves) beneath the glacier, at elevations between 5,200 m and 5,500 m, including both White-winged Diuca Finch and White-fronted Ground-Tyrant, as well as Plumbeous Sierra Finch (Phrygilus unicolor), Rufous-bellied Seedsnipe (Attagis gayi), and Gray-breasted Seedsnipe (Thinocorus orbignyianus). These nesting and roosting behaviors are all likely adaptations to the harsh environment, as the glacier provides a microclimate protected from precipitation, wind, daily mean temperatures below freezing, and strong solar irradiance (including UV-B and UV-A). Indeed, the global range of White-winged Diuca Finch coincides relatively closely with the distribution of Andean glaciers, and because no nests are known to have been found away from ice, this species may be a glacier obligate. Given the number of individuals observed and diversity of species associated with, and possibly dependent on, the ice, ongoing loss of tropical glaciers may have a direct, negative effect on High Andean biodiversity. [ABSTRACT FROM AUTHOR]

Females often invest more in parental care than males, but in socially monogamous systems, males invest as much as females in caring for their offspring, and male contribution is believed essential for reproductive success in these systems. Here we describe the number of visits, the feeding rate to their nestlings, and the time on the nest invested by each sex of the socially monogamous songbird, the Clay-colored Thrush ( Turdus grayi), for 16 nests in San José, Costa Rica. Both males and females fed their nestlings at a similar rate, but females visited the nests more frequently than males. The feeding rate of both females and males was also similar when controlled by age of nestling. The feeding rate was highly variable across males (minimum 1, maximum 15 visits per 2 h), possibly related to the probability of males fathering the offspring of the attended nest. Females spent more time on the nest than males, but males tended to remain near the nest to defend it from predators. Moreover, male contribution during the nestling period correlated with the reproductive success. [ABSTRACT FROM AUTHOR]

In this study I examined heterospecific eavesdropping in passerines by investigating how information broadcast by the Tufted Titmouse ( Baeolophus bicolor) at dusk modifies singing and calling vocalizations of a common avian dusk chorus species, the Veery ( Catharus fuscescens). The Veery nests on or near the ground and is a highly vocal participant of the avian dusk chorus, which also renders it vulnerable to a wide array of diurnal and crepuscular predators. Thus, the Veery is expected to be sensitive to signals of predation risk. Here, I report findings of simulated exposure to indirect predation risk (recorded playbacks of Tufted Titmouse alarm calls) that alter acoustic output by the Veery. From 19 May to 6 July 2013, 14 plots in Veery territories were selected and exposed to playback calls of the gray tree frog ( Hyla versicolor; control treatment) and playbacks of the Tufted Titmouse high seet call (experimental treatment). Each plot was subjected to two 65 min playback-recording trials (one experimental and one control); Veery song and call output were quantified via spectrograms to compare Veery acoustic response between treatments. The Veery produced a greater call output while song output remained unchanged between control and experimental treatments. These results reveal that the Veery indeed detected and responded to heterospecific alarm calls. Moreover, the Veery acted as a secondary community informant, further transmitting information regarding predation risk to conspecifics and the dusk chorus community at large. [ABSTRACT FROM AUTHOR]

Historically, the genus Scliiffornis has been placed in different families; currently, it is placed within the Tityridae family. Our study focuses on Schiffornis stenorhyncha, recently split from Schiffornis turdina. S. stenorhyncha inhabits lowland humid forests in some regions of Panama, Colombia, and Venezuela. Based on one nest found at the foothills of the Magdalena Valley in Colombia during one field season in 2014, we provide the first nest description for 5. stenorhyncha. We describe the cup-shaped nest (internal length and width: 22.9 and 18.1 mm. thickness of the nest wall: 30 mm, cup depth: 56.6 mm, external length, width, and height: 139.4 mm, 144.2 mm, 115.7 mm) and the light cream with dark purple spotted eggs (two eggs with average measures of 18.3 X 23.2 mm and 4.49 g) of .S', stenorhyncha and present nesting information including nestling descriptions, incubation, and nestling periods (21 and 20 days, respectively), and nest attentiveness information in different stages of the nest (4.72 trips a day during incubation and 1.25 trips per hour during the nestling stage). We compare our findings with other Schiffornis species and related species in the Tityridae family. [ABSTRACT FROM AUTHOR]

The Striated Caracara (Phalcoboenus australis) is a poorly known raptor associated with seabird colonies, restricted to the islands of southern South America, and with an estimated extant population of <2,500 mature individuals. We evaluated the number of breeding pairs, described the characteristics and spatial pattern of nest sites, and estimated breeding output of a population of Striated Caracaras in Franklin Bay, Staten Island, Argentina. We found one of the lower breeding density values reported for this species, although this population is associated with one of the biggest colonies of Rockhopper Penguins. The main material used for the construction of Striated Caracaras' nests was tussac grass, though only half of nests were placed in grassland. The spatial pattern for nest sites corresponds with global and local clustering. All successful Striated Caracaras' nests were at least 250 m from the nearest neighboring nest, were generally closer to the colony of Rockhopper Penguins than failed nests, and had more Rockhopper patches around them. Breeding success was 0.73 successful nests/active nests, productivity was 1.27 ± 1.01 young/active nest, and brood size was 1.75 ± 0.71 young/successful nest. The presence of invasive wild goats and red deer is proposed as a factor that could be restricting nest site availability in the study area. Received 24 October 2016. Accepted 29 March 2017. [ABSTRACT FROM AUTHOR]

Organisms with limited motility may use animal transport as a mechanism for dispersal. Migratory birds can provide a vehicle to move small organisms great distances, which may allow them access to areas that are otherwise inaccessible. During normal mist netting operations at a spring migration banding station along the northern Gulf of Mexico coast in Louisiana, USA, we encountered an Indigo Bunting (Passerina cyanea) with numerous snails, possibly Galba cubensis, underneath its breast feathers. While encounters of songbirds carrying snails appear rare, long-distance migrating songbirds represent a possible mechanism to transport small snails great distances to expand ranges, colonize new areas, or maintain genetic continuity. [ABSTRACT FROM AUTHOR]

Disturbance foraging - the use of disturbances created by other animals to locate cryptic or sedentary prey - is a widespread phenomenon, particularly in birds. In the Neotropics, a prominent example of disturbance foraging in birds is their relationship with army ants (Eciton burchellii). Numerous bird species attend army ant swarms and forage on the prey that the ants flush from the leaf litter. Here, I document a previously undescribed disturbance foraging association between two species of obligate ant-following birds and a small anteater, the northern tamandua (Tamandua mexicana). 1 observed both bird species approach and forage on fallen termites underneath the anteater, which was excavating a termite nest. The foraging association appeared to be a commensal relationship - the antbirds obtained a foraging benefit from the anteater, which was in turn unaffected by the birds. My observation suggests that ant-following birds may respond to other disturbances in addition to army ant swarms to find food. [ABSTRACT FROM AUTHOR]

Male birds of prey are usually smaller than females, known as "Reverse Size Dimorphism" (RSD). We quantified sexual size dimorphism in species that occur in Brazil, and suggest a bootstrap-based approach that allows an estimate of confidence intervals for dimorphism indices. We used body mass, total length, and wing length, measured from museum specimens and a few live birds, to quantify size. We gathered data from eight owl species, for which sample sizes were considered to be minimally adequate to provide reliable dimorphism estimates. We calculated a dimorphism index (Dl) for each measurement and then these indices were reduced to a single latent variable using a principal component analysis. A clear trend toward positive Dl values confirms RSD as a general pattern, except for negative values in Asio clamator (Striped Owl) for all measurements, for total length in Athene cunicularia (Burrowing Owl), and Ciccaba virgata (Mottled Owl), and for virtually equal to zero values in Pulsatrix koeniswaldiana (Tawny-browed Owl) for total length and A. cunicularia for wing length. Body mass was the most dimorphic trait in all species and Dl values were consistent across all three traits. Wing length Dl was the most precise index and total length Dl was the least precise index. In descending order of overall RSD the species studied were Strix hylophila (Rustybarred Owl), Megascops choliba (Tropical Screech-Owl), Glaucidium brasilianum (Ferruginous Pygmy-Owl), Tyto alba (Barn Owl), P. koeniswaldiana, C. virgata, A. cunicularia and A. clamator. [ABSTRACT FROM AUTHOR]

Scavenging has been increasingly documented for difficult to observe species through advances in motion-triggered photography. Here, we document several instances of scavenging over multiple days by a Northern Hawk Owl (Surnia ulula) on a Canada lynx (Lynx canadensis) carcass. These observations are of particular interest because the owl visited the carcass 25 times, with the longest visit lasting >3 hrs. In addition, the owl routinely defended the carcass against Black-billed Magpies (Pica hudsonia). These observations suggest scavenging may represent a larger role in the diet of Northern Hawk Owls; further research is required in order to understand its importance for this and other raptor species. [ABSTRACT FROM AUTHOR]

The American Golden-Plover (Pluvialis dominica), a species of conservation concern, uses large agricultural fields during its spring passage through the midwestern United States. In west-central Indiana, large numbers of golden-plovers make a stopover in com or soybean fields that were harvested the previous fall. Stopovers last for a number of days during which the birds feed and molt into alternate plumage. In recent years, wind energy facilities have been developed in the area with hundreds of wind turbines erected in fields used by the golden-plovers. During spring 2011 and 2012, we investigated patterns of golden-plover behavior at these facilities in Benton County, Indiana at a site where large spring aggregations of plovers have been observed for many years. Our results showed only limited behavioral avoidance of the turbines, and suggested that wind-energy development in this area was not significantly impacting migrant goldenplovers. However, we caution that additional studies could negate these somewhat tentative findings, and we urge that further evaluation precede possible expansion of wind energy development in the region. [ABSTRACT FROM AUTHOR]

Diet studies provide information about a species' ecology, evolution, and behavior. The Araripe Manakin (Antilophia bokermanni) is a critically endangered, endemic, and sexually dichromatic species from northeastern Brazil. Little is known about its natural history, and as an endangered bird, information about diet may be crucial for conservation plans. We analyzed the diet of Araripe Manakins and tested if food items and foraging behavior differed for males and females. We caught and banded birds, and analyzed fecal samples. Using focal observations, we collected foraging behavioral data, including vegetation strata used, foraging bout duration and gathering method. Based on data gathered from 40 females and 54 males, we found that the Araripe Manakins' diet contains both plant and animal items including 10 different types of fruits and three orders of invertebrates. Clidemia biserrata was the most important plant item consumed, representing 80% of the diet. There was a substantial overlap of 68% of food items in the diets between sexes, which did not differ statistically. However, male and female diets were unique in some aspects: females consumed more items having a more diverse diet when compared to males. Males, however, consumed more Coleoptera, and these were the second most important item in their diets. Since male and female foraging behavior does not differ, this result suggests that males choose to consume more beetles perhaps to maintain plumage color, since beetles are rich in carotenoids. Results also provide important data about which plants can be used in the management or recovery of Araripe Manakins' habitats. [ABSTRACT FROM AUTHOR]

Understanding sex-specific differences in behavior and survival is essential for informative population modeling and evolutionary biology in animal populations. Uneven sex ratios are common in many migrant passerine species; however, the underlying mechanisms remain unclear. We used molecular sex determination, nest monitoring, and radio telemetry of fledgling Ovenbirds (Seiurus aurocapilla), to determine if sex-specific patterns of production, survival or behavior were present prior to the first migration. We tested whether: 1) sex ratios were skewed towards males at fledging; 2) postfledging survival of males was higher than females; 3) distances moved over time were equal between sexes; and 4) if observed parental care was equal between sexes over time. We determined the sex of 33 hatch-year Ovenbirds in central Missouri in 2015 and followed 19 individuals using radio telemetry. We found no difference in sex ratios within broods, overall numbers of male (n = 18) and female (n = 15) nestlings, or in the survival of male (n = 8) and female (n = 11) fledglings followed with radio telemetry. However, we did find that sex affected the relationship between age and distance moved from the nest, suggesting females moved further from the natal site after independence from adults. These results provide a better understanding of postfledging ecology and support the common assumption that annual production of females is half of total productivity, a fundamental premise in most population growth models [ABSTRACT FROM AUTHOR]

Disturbance because of human activity, including recreation on wildlands, can affect bird behavior which in turn can reduce breeding success, an important consideration for species of management concern. We observed Golden Eagles (Aquila chysaetos) during the breeding season to determine whether the probability of flushing was affected by the type of recreationist, distance to encounter, eagle nest attendance, or date. We monitored eagles in 23 nesting territories from distant (600-1,200 m) observation points and recorded recreation activity within 1,200 m of eagles in the Owyhee Front of southwestern Idaho. In most (86%, n = 270) encounters, eagles did not flush in response to recreationists; however, whether an eagle flushed was affected by the type of recreationist and whether an eagle was at or away from the nest. Eagles were 60 times more likely to flush in response to recreationists that stopped a motor vehicle and transitioned to walking (11 of 17 passes) and 4.5 times more likely to flush in response to off-road vehicle (ORV) riders (17 of 121 passes) than during encounters with road vehicles (7 of 107 passes). Flushing was 12 times more likely for eagles away from nests (23 of 87 passes) than eagles at nests (13 of 183 passes). Eagles flushed at greater distances in response to recreationists that transitioned from motor vehicles to walking (lsmean = 620 m) than when responding to either ORV riders (lsmean = 525 m) or road vehicles (lsmean = 318 m). Flushing distances tended to decline throughout the breeding season to suggest seasonal changes in the costs and benefits of responding to disturbance. After flushing from nests, most eagles (77%) spent <40 mins away, but some (23%) spent >90 mins away from nests. Limiting recreational activities within 650 m and 1,000 m of nest sites may decrease nest-site flushing events by 77% and 100%, respectively. Because eagles seem most sensitive to humans transitioning between motorized and non-motorized recreation, land managers may strike a balance between access needs of recreationists and buffering eagles from disturbance by using a mix of trail closures and no-stopping zones that prevent transitions from motorized to walking activities. [ABSTRACT FROM AUTHOR]

We report new observational and specimen data on the avifauna of Kolombangara, Western Province, Solomon Islands. These data, collected from 3-9 October 1974 and 13-21 May 2004. and supplemented with more recent observations, represent the first comprehensive survey of this globally significant island since 1927. All encounters of montane species are reported along with select species accounts for notable lower-elevation species. Numerous observations presented here suggest avifauna even more unique than previously reported. For example, we confirm a probable resident form of Peregrine Falcon (Falco peregrinus) and report the first observations and collected materials for a Blue-faced Parrotfinch (Erythrura trichroa) from Kolombangara. We observed all of the island's high-elevation endemics and found their relative abundances and patterns of occurrence to be consistent with those of an intact montane avifauna. Our findings suggest that despite large-scale modification of lowland habitat, montane forests on Kolombangara still maintain the full complement of endemic and other high elevation species described nearly 100 years ago, along with several additional taxa not previously recorded. However, incidental evidence suggests that forest change in the lowlands is impacting montane microclimates as indicated by extensive drying of epiphytic mosses at high elevations. Along with more recent collection of undescribed anurans, these findings confirm the global conservation significance of the montane forests and biodiversity on Kolombangara. [ABSTRACT FROM AUTHOR]

We studied the relationship between song repertoire size, territorial behavior, and nesting success in Pied Bush Chat (Saxicola caprata) in Haridwar (Himalayan foothills), India for three consecutive years (2013-2015). Our findings indicate song repertoire size is correlated with nesting success, but pre-nesting territory size, average territory size, and territorial conflicts are independent of song repertoire size. It may be inferred that larger territories are not necessarily better territories. The findings suggest that larger territory size is more susceptible to increased territorial conflict. Significant differences were apparent between territory size and territorial conflicts in the different stages of the nesting cycle. The findings suggest that larger territory size is more susceptible to increased territorial conflict. We propose that even if territorial conflicts are independent of song repertoire size, the amount of territorial conflict may be constrained by the stage of nesting cycle or size of the territory. Depending upon breeding requirements, male Pied Bush Chats tailor their territory sizes and territorial conflicts during the course of the breeding season. [ABSTRACT FROM AUTHOR]

We investigated singing patterns of Pied Bush Chats across years and nesting cycles. We recorded the seasonal singing activity of 25 males in their natural habitats in Haridwar, Himalayan foothills, India for three consecutive years. The vocal patterns, especially song repertoire size of males, remained largely constant, and this restricted annual variation suggests that the Pied Bush Chats are closed-end learners. Analysis of song bouts during different stages of the nesting cycle and across years indicates that the Pied Bush Chat is an immediate variety singer. The song output in terms of song complexity, song rate, song bout length, and percentage performance time was highest at the beginning of egg laying and during incubation compared to pre-nesting, nest building, and provisioning stages. Such singing peaks with respect to different stages of the nesting cycle indicated mate guarding by male Pied Bush Chats and announcement of fertility status of the guarded female. [ABSTRACT FROM AUTHOR]

Whereas most host species parasitized by Brown-headed Cowbirds ( Molothrus ater) accept cowbird eggs in their nests, others reject the foreign eggs or desert parasitized clutches. Chipping Sparrows ( Spizella passerina) are a nest deserting host of cowbirds, but many of their nests continue to be incubated with cowbird eggs suggesting that cowbird eggs per se do not necessarily trigger desertion. We demonstrate that encounters with an adult female brood parasitic cowbird rather than with a cowbird egg in the nest, elicit nest desertion. We observed that a total of 33 (67.3%) of 49 nests were naturally parasitized in Illinois. Parasitized nests fledged less than one third of the number of host young than unparasitized nests did, indicating that parasitism is extremely costly in this species and that an evolved response to parasitism would likely spread through the population over time. [ABSTRACT FROM AUTHOR]

Caribbean Martins ( Progne dominicensis) are common breeders on most Caribbean islands, where they regularly roost and nest in urban areas from February through August. However, from September through January, the basic ecology of this species-its migration and wintering locations-are largely unknown. In 2012, we deployed seven geolocators, and in 2014, we recovered one geolocator from a female Caribbean Martin on the Commonwealth of Dominica, a small eastern Caribbean island. Her wintering location was the western portion of the State of Bahia, Brazil, ∼3550 km southeast of Dominica. Although the location of the non-breeding grounds changed minimally, the fall departure date, migration route, and length of migration to western Bahia, Brazil, was different between years. In October 2012, the female followed a coastal migration route along the Atlantic coast of South America, then flew south to the non-breeding grounds. However in Oct 2013, she flew south from Dominica through Guyana, spent a few days in the Amazon rain forest, and then migrated southeast to the non-breeding grounds. These results provide insight into the repeatability of migration routes and wintering locations by this species, and serves as a first step in better understanding the Caribbean Martin's full life-cycle. [ABSTRACT FROM AUTHOR]

Coprophagy by breeding birds, whereby parents eat the feces of their nestlings, is a common but rarely studied behavior. By eating feces, breeding parents may recycle nutrients. In many passerines, eating feces also reduces breeders' time away from the nest, saving energy and increasing brooding time. Here, we report the proportion of individuals that display coprophagy in a population of Dunnocks, Prunella modularis, in Dunedin (New Zealand), and evaluate whether coprophagy varies between sexes, and between two mating systems (monogamy and polyandry). We find that females consume fecal sacs significantly more frequently than males. We also find a non-significant trend for monogamous females to eat feces more often than polyandrous females. We conclude that two hypotheses - parental-nutritional and economical-disposal - could explain the differences in coprophagy between sexes. Our results also suggest that male Dunnocks may engage in coprophagy to recycle nutrients rather than for saving energy. Finally, we describe a novel observation of a nestling being fed with its own feces by an adult male. [ABSTRACT FROM AUTHOR]

We present the first record of the Ascension Frigatebird ( Fregata aquila) for the Americas by retrieving coordinates from an individual equipped with a satellite transmitting device. As part of a wider study on the spatial and behavioral ecology of this species, we tracked a single juvenile frigatebird that entered into Brazilian waters as defined in the guidelines set forth by the Brazilian Ornithological Records Committee and the South American Checklist Committee. In total, this individual traveled ∼45,000 km over a 3.5-month period before transmissions ceased close to the exclusive economic zone of Sierra Leone. Based on the potential for this species to wander, the Ascension Frigatebird should be considered when attempting to identify any frigatebird in the Atlantic Ocean. Importantly, this record demonstrates the great potential for satellite telemetry to inform national ornithological and conservation organizations on the presence of pelagic seabirds that may otherwise be overlooked by visual surveys. [ABSTRACT FROM AUTHOR]

The Torrent Duck ( Merganetta armata) is one of the four species of ducks that live in fast flowing rivers, and the only one inhabiting mountain rivers from Venezuela to Argentina. This study examines physical-chemical and biological environmental variables associated with different stages of the annual cycle of this waterfowl, to test the relationship between environmental variables and the establishment of territories by Torrent Ducks in the southern part of their range between November 2009 and April 2011. Territories were defined as sites where a pair of Torrent Ducks was found throughout the year, while non-territories were defined as sites where solitary birds were spotted in some seasons but not year-round. The variables that best explained the habitat use by Torrent Ducks were: 1) in spring, the energy of main prey items available per square meter of river, and 2) in fall, the flow rate. Higher food availability in spring and higher water flow in small rivers in fall were associated positively with paired Torrent Ducks' territory establishment. The future assessment of breeding success in territories with contrasting levels of food and water flow may allow for the determination of the importance of these variables for habitat selection, and the meaning that changes in precipitation caused by climate change may have on this species. [ABSTRACT FROM AUTHOR]

We studied the response of Water Rails ( Rallus aquaticus) to conspecific and heterospecific playback to reveal any variation in reaction to playbacks of rail and crake and if and how these reactions change in intensity. Ten observation points, 100 m from each other within a reedbed, were selected. We made our observations three times a day over three days in three sessions (Apr, Jun, and Sept). We quantified the response of Water Rails to the playback of conspecifics and the heterospecifics: Common Moorhen ( Gallinula chloropus), Corn Crake ( Crex crex), Little Crake ( Porzana parva), Spotted Crake ( P. porzana), and Baillon's Crake ( P. pusilla), in terms of phenological periods. We found that there is a difference in aggressive reaction between conspecific and heterospecific playbacks across all sessions and also within each session. The aggressive reaction decreases significantly in the direction (Water Rail = Common Moorhen) > (Corn Crake = Little Crake = Spotted Crake) > (Baillon's Crake), during the first session and (Common Moorhen) > (Water Rail) > (Corn Crake = Little Crake = Spotted Crake = Baillon's Crake) during the second session. We found that Water Rails react differently to conspecific and heterospecific calls. The reaction intensity changes from one session to another, and the level of reaction to different species also changes. Most of the aggressive reaction levels can be explained by nesting place and food competition but also nest parasitism behavior and body mass differences. [ABSTRACT FROM AUTHOR]

We provide the first description of nest architecture and composition, adult construction behavior, and egg characteristics for the genus Rhytipterna. We provide these data for a nest of the Rufous Mourner ( Rhytipterna h. holerythra) found under construction and followed through clutch completion and subsequent failure at La Selva Biological Station, Heredia, Costa Rica. Given the historically labile taxonomic placement of the genus Rhytipterna, our observations provide important additional lines of evidence further supporting its affinity to Myiarchus within the Tyrannidae. We highlight our record of the incorporation of shed reptile skins in the nest lining, only the second instance of this nest character within Tyrannidae outside of the genus Myiarchus. The phylogenetic distribution of this specialized nesting trait suggests the possibility of a single origin near the base of the subclade Tyranninae. Received 29 August 2016. Accepted 30 November 2016. [ABSTRACT FROM AUTHOR]

Increasing populations of Hooded Mergansers ( Lophodytes cucullatus) (Heusmann et. al 2000) may be out-competing Wood Ducks ( Aix sponsa) for nest boxes on some sites in Massachusetts. Hooded Mergansers' use increased from ≤2% of boxes in 1979 to 25% by 2013, while Wood Ducks' use increased from an average of 22% in 1979 to a peak of 65% by the mid-1990s and has since declined to 57%. We estimate that Hooded Mergansers may be important nest competitors on 13 of 51 study sites. [ABSTRACT FROM AUTHOR]

High arctic latitudes are characterized by short summers with continuous daylight, high seasonality, and low temperatures. In stable bird populations, mortality risks associated with the harsh climate and/or the long migration to reach the Arctic should be balanced by increased recruitment to the population through increased fecundity. We report on annual reproductive success of the American Robin ( Turdus migratorius) nesting at its most northerly geographic limits in Ivvavik National Park, Yukon Territory, Canada during the 2010-2012 breeding seasons. Our objective was to determine whether fecundity was increased relative to similar populations breeding at more southerly latitudes. We also examined inter-annual variation in breeding parameters, which we predicted would vary because of interannual variation in local weather conditions. Clutch completion date, clutch size, and fledglings per nest varied significantly among years. No re-nests or double-brooding were documented. There was a significant decrease in incubation period and increase in nest success and clutch size with increasing latitude. Nests in Ivvavik National Park contained more fledglings per successful nest than nests farther south, and the nestling period (11 days) was the shortest recorded for this species. The lack of double-brooding appears to be at least partially compensated by higher fecundity during the single breeding event, at this northerly location. [ABSTRACT FROM AUTHOR]

From 2010-2012, I studied nesting success and causes of nest failure at a colony of Barn Swallows ( Hirundo rustica) where anecdotal evidence suggested the colony was declining in size. In 2010, many nests were destroyed, and indirect evidence suggested breeding adults were being depredated by a raptor. Using trail cameras, I captured video evidence of Barred Owls ( Strix varia) depredating two nests, one containing chicks and the other eggs. During the study period, 72% (32/44; 2010), 51% (16/31; 2011), and 85% (17/20; 2012) of nests were depredated, and the number of nesting attempts declined by more than 50% over 3 years. The video evidence and plucked adult feathers suggests that Barred Owls were responsible for at least some of the predation. Barred Owls did not breed historically on the southern British Columbia coast but first appeared in 1966 and have become common breeders, while Barn Swallows have decreased in the same region by 5.64% per year since 1970. There may be many causes of local and regional population declines of Barn Swallows, but given their conspicuous nests, predation in less well protected nesting sites may be a localized cause of colony decline. [ABSTRACT FROM AUTHOR]

We studied the breeding biology of the Fire-tailed Myzornis ( Myzornis pyrrhoura) in an alpine environment (3000-3800 m) of the Gaoligong Mountains in southwestern China during its breeding seasons in 2013 and 2014. Nests were built by both sexes and mainly contained moss and rhododendron flakes. They were located on vertical banks or rock faces, about 20-152 cm above the ground. This species was socially monogamous and sexually dimorphic both in plumage pattern and body size. Egg-laying was mainly initiated in mid-April and ended in early July, and the mean date of clutch initiation was 25 April in 2013 ( n = 4) and 27 April in 2014 ( n =5), respectively. The clutch size averaged 3.00 ± 0.15 ( n = 10), and fresh eggs weighed 1.84 ± 0.19 g ( n = 11). Males and females made virtually equal contributions in breeding activities, including incubation, provisioning, brooding, and nest sanitation. Incubation lasted for 15 days ( n = 2) with a notably high nest attendance (eggs were incubated 99.48% of the time). The total provisioning rates were 6.52 ± 1.82 (range = 3.29-10.29) trips per hour, a rate that did not change significantly throughout the nestling period. Nestlings fledged at 19.67 ± 0.33 ( n = 3 nests) days after hatching, when they were 19% heavier than adults. Growth of nestlings met logistic expectations except for tail length. Overall, the reproductive success rate was 42.86%. Compared with other lower-elevation breeding babblers, Myzornis had larger and heavier nests, fewer but larger eggs, and a longer nestling period. These life-history traits may facilitate its reproduction in the cold alpine areas of the Gaoligong Mountains. [ABSTRACT FROM AUTHOR]

Red-winged Blackbirds ( Agelaius phoeniceus) experience high rates of nest predation and are therefore expected to exhibit adaptations to reduce the risk of eavesdropping by predators. We used a simulated predator and observations of adult and nestling behavior to test predictions of the predator eavesdropping hypothesis. Females ( n = 42) delayed their feeding visits significantly longer and took significantly longer to complete their round trips when a plastic American crow ( Corvus brachyrhynchos) was 20 m from their nests than when a black wood block was at the same location, but time spent off territory foraging did not differ significantly. Nestlings ( n = 35 broods) begged appropriately (in response to a female at the nest) significantly less and at significantly lower intensity when the plastic crow was 20 m from their nests than when the wood block was at the same location, but the crow had no significant effect on the amount or intensity of inappropriate (no female present) begging. These and other results demonstrate that adult and nestling Red-winged Blackbirds have evolved adaptations to reduce nest predation. [ABSTRACT FROM AUTHOR]

Breeding cavity-nesting seabirds on remote, oceanic islands are threatened largely by destruction of nest cavities and introduced predators. In response, artificial cavities are often implemented as a conservation strategy. Effective artificial cavity programs require recognition of specific nest-site characteristics, which can be major determinants of survival and persistence of cavity-nesting seabirds. In Bermuda, we monitored 158 natural and 178 artificial cavities of the White-tailed Tropicbird ( Phaethon lepturus catesbyi) from 2013-2015 to determine if specific nest-site characteristics could explain cavity selection, nest survival, and predation by introduced rats ( Rattus spp.) and the American Crow ( Corvus brachyrhynchos). We found that tropicbirds preferred natural cavities lined with sand, and which had smaller entrances and were located on steeper cliffs. Occupancy of artificial cavities on the mainland varied across years and increased with cavity depth, whereas neither variable had any effect on artificial cavity occupancy on satellite islands. Clutch survival declined in cavities with rubble in nesting sand, and those with shallower cavity depths and larger entrance heights. Nestling survival varied by year, declined as the nesting season progressed, and increased with nestling age. Rat predation was significantly higher on mainland sites compared with satellite islands. Crow predation occurred only on offshore island sites, where natural cavities and shallower cavities with larger entrance heights were vulnerable. Rat and crow predation rates varied across years. Our results suggest multiple nest-site characteristics and temporal factors are important predictors of productivity in White-tailed Tropicbirds. Conservationists should simultaneously consider nest-cavity siting and dimensions, while they conduct biosecurity and predator control to improve the nest success of cavity-nesting seabirds. [ABSTRACT FROM AUTHOR]

The Dark-eyed Junco ( Junco hyemalis) is one of the most abundant birds in North America and exhibits versatility in its selection of nest sites. Although typically ground-nesting birds, juncos also nest occasionally in trees, on buildings, and in natural recesses such as rock crevices. To our knowledge, juncos have never been reported nesting in a fully enclosed nest box specifically provided for songbirds. We report the first record of nest box adoption by Dark-eyed Juncos, supported by photographic evidence. A nest box containing a nest attended by a pair of Dark-eyed Juncos was monitored in 2016 in western Washington, USA, and reported to the Cornell Lab of Ornithology's NestWatch program, a national citizen-science program wherein volunteers submit data on wild nesting birds. The nest in question hatched successfully, and three nestlings fledged from the box. Cavity nesting in New World sparrows appears to be very rare, and we found only four additional observations of juncos utilizing natural cavity nests (i.e., a tree hole). Engaging the public to monitor large numbers of nests is the most likely approach to documenting novel nest sites, and citizen science provides the infrastructure for individuals to share observations. [ABSTRACT FROM AUTHOR]

Western Chat-Tanagers ( Calyptophilus tertius) are a rare and globally vulnerable songbird endemic to the island of Hispaniola. We conducted a radio-telemetry study of non-breeding Western Chat-Tanagers at two adjacent cloud forest sites in Sierra de Bahoruco in southwestern Dominican Republic during March and April of 2010. Male home ranges averaged 2.18 ± 0.25 ha in size ( n = 4) and were significantly larger than those of females (0.88 ± 0.04 ha; n = 2). However, core use areas did not differ significantly between the sexes. We assumed that males and females with overlapping home ranges were mated pairs. At night, two putative pairs roosted an average distance apart of 15.8 ± 3.5 m ( n = 7 observations). [ABSTRACT FROM AUTHOR]

Grebes are unique among birds in ingesting their own feathers. This behavior and the subsequent ejection of feathers as pellets have long puzzled ornithologists, who have tended to treat feather-eating and pellet-casting as independent behaviors rather than as complementary components of the digestive process. The diet of many grebes, including those with the most ancestral traits, is dominated by small invertebrates whose exoskeletons are resistant to digestion. Most birds eat grit to mechanically break down hard foods. Not so with grebes, which are chemical digesters. Feather-eating performs two main functions. The first is to retain food until it is fully digested; this is accomplished by a large feather bolus in the gizzard. The second, provided by a distinct group of feathers in the pyloric pouch, is to filter undigested or indigestible items from entering the intestine. Some of the gizzard bolus is probably regurgitated nightly, but the process is incomplete and undigested food can persist in the gizzard overnight and indigestible hard parts for several months. The pyloric plug is expelled irregularly. Inasmuch as feathers and other debris must eventually be discarded, pellet-casting is an inevitable consequence, not cause, of feather-eating. I propose that grebes originated as surface feeders and adopted feather-eating to enhance the efficiency of feeding on small arthropods or other hard-bodied taxa that are difficult to digest. This interpretation is relevant to understand the early evolution of grebes. [ABSTRACT FROM AUTHOR]

Warming temperatures have been linked to advancing spring migration dates of birds, although most studies have been conducted at individual sites. Problems may arise ecologically if birds arrive or depart before or after associated food resources such as plants or insects reach critical lifecycle stages. Here, I compare mean first arrival dates of the Rufous Hummingbird ( Selasphorus rufus), a prolific pollinator and long-distance migrant with the northernmost breeding range of any North American hummingbird, between 1895-1969 and 2006-2015 at eight observation locations in Oregon, Washington, and British Columbia. Historical arrivals were reported through the North American Bird Phenology Program, and recent arrivals were estimated from temporal occupancy patterns using eBird checklists. Results indicated that hummingbirds arrived 8 and 11 days later in the recent time period in two coastal cities in Oregon and 7-17 days earlier in northern, more inland cities in Washington and British Columbia. Fewer days were noted between arrivals in more northerly areas in the recent time period suggesting that birds may now be migrating faster than in the previous time period. Spring temperatures have increased in the past century in much of this region, and birds arrived earlier in years with warmer spring temperatures to suggest that migratory advances are climate-related. Later mean first arrivals reported in coastal regions of Oregon in the recent time period may suggest that Rufous Hummingbirds are bypassing coastal areas to take advantage of more predictable conditions along inland migratory routes or are shifting their breeding ranges northward, notions both supported by declining population trends observed in Breeding Bird Survey data. My results demonstrate a climate-related advancement of Rufous Hummingbirds in western North America and provide justification for the investigation of the ecological impacts of climate change on birds in coastal vs. inland environments. In addition, I provide a framework for comparing information from two extensive and emerging datasets to better understand the impacts of climate change on birds at broad spatial and temporal scales. [ABSTRACT FROM AUTHOR]

Juvenile birds are generally less efficient foragers than adults, and this can lead to reduced survival or delayed reproduction. Feeding on hard-shelled nuts and mollusks after breaking them open by dropping is particularly challenging. To determine whether juvenile birds are as proficient as adults at this complex foraging task, we compared juvenile and adult Herring Gulls ( Larus argentatus) feeding at low tide by dropping clams ( Rangia cuneata) at a coastal estuary in Virginia, USA. Juvenile (first-winter) gulls were less successful than adult (2+ years old) birds at finding clams to drop. Moreover, the clams they selected were of a wider range of sizes, more often being difficult to handle or of lower nutritional value. Juveniles did, however, drop clams with the same degree of success as adult birds. Together these results suggest that learning to find and recognize profitable clams is the developmental bottleneck in this complex behavior. [ABSTRACT FROM AUTHOR]

Although polygyny is common and regular among a small proportion of North American songbirds, some socially monogamous passerines may also exhibit occasional polygyny. We present evidence for only the second documented case of polygyny within the Vireonidae and the first documentation for polygyny in the endangered songbird the Black-capped Vireo ( Vireo atricapilla). We located two simultaneous nests being tended by the same color-banded male vireo in a territory adjacent to an unpaired male. We suspect that differences in territory quality, rather than male quality, unbalanced sex ratios, or asynchronous settlement, were drivers of polygyny in this example. [ABSTRACT FROM AUTHOR]

The hormones prolactin (PRL) and testosterone (T) are linked to breeding behaviors such as territory defense, incubation, and brood-rearing in birds. The Mountain Plover ( Charadrius montanus) is a shorebird with an uncommon parental care system in which males and females tend separate nests. We collected blood from incubating male ( n = 38) and female ( n = 33) Mountain Plovers in Montana to determine how circulating plasma PRL and T varied by sex, day of incubation, and across the nesting season. PRL levels were similar in males and females. There was no relationship between day of incubation or Julian day and circulating PRL for either sex. T concentrations were higher in males than in females and tended to decrease across the incubation season for both sexes. [ABSTRACT FROM AUTHOR]

The Common Raven ( Corvus corax) is a ubiquitous species in the Mojave Desert of southern Nevada and California. From 5 to 24 May 2014, using remote trail cameras, we observed ravens repeatedly kleptoparasitizing food resources from the nest of a pair of Golden Eagles ( Aquila chyrsaetos) in the Spring Mountains of southern Nevada. The ravens fed on nine (30%) of the 30 prey items delivered to the nest during the chick rearing period. Kleptoparasitic behavior by the ravens decreased as the eagle nestling matured to seven weeks of age, suggesting a narrow temporal window in which ravens can successfully engage in kleptoparasitic behavior at eagle nests. The observation of kleptoparasitism by Common Ravens at the nest suggests potential risks to young Golden Eagles from Common Ravens. [ABSTRACT FROM AUTHOR]

Nest collapse has been documented in many bird species, with little discussion of adult behavior following collapse. We present evidence of a partial collapse of a Gyrfalcon ( Falco rusticolus) nest during the nestling period and the subsequent adult response. A nest camera captured the nest collapse and showed one adult Gyrfalcon holding a live nestling in its beak before leaving the nest. Later, we found the surviving nestling alive in an alternate nest 5 m from the original nest, presumably transported there by the adult. We believe this is the first report of an adult Gyrfalcon moving a nestling to a new location following nest disturbance. We place this observation into a context of Gyrfalcon nesting behavior described in published sources. The continued use of nest cameras may provide additional documentation and insight into this behavior and its prevalence in birds. [ABSTRACT FROM AUTHOR]

We observed a fledgling abandonment and adoption event that subsequently led to an extended period of interspecific parental care between a male Black-and-white Warbler ( Mniotilta varia) and two radio-tagged fledgling Golden-winged Warbler ( Vermivora chrysoptera) siblings. Both fledglings were initially accompanied by their maternal Golden-winged Warbler until 5 and 9 days after fledging. At this time, a male Black-and-white Warbler began feeding both fledglings, and maternal care ceased. In the 23 days we monitored the fledglings between onset of interspecific feeding and independence, the male Black-and-white Warbler was observed with at least one of the fledglings on 20 of those occasions. Furthermore, the Black-and-white Warbler was seen feeding at least one of the fledglings on 16 of those visits. We photographed several feeding events. The Black-and-white Warbler remained with the fledglings until they successfully reached independence 28 days post-fledging. [ABSTRACT FROM AUTHOR]

Studies of avian escape behavior have mostly focused on nonbreeding birds, however the costs and benefits of escape behavior are predicted to vary depending on whether or not birds are breeding. Passive nest defenders may escape an approaching threat earlier than would otherwise be the case as an adaptation that helps conceal their cryptic eggs. Alternatively, the investment in the clutch may mean that birds delay escape. We tested these predictions on a population of passively defending Little Tern (Sterna albifrons) and Kentish Plover (Charadrius alexandrinus) within the Saemanguem reclamation area, South Korea. Incubating terns exhibited longer flight-initiation distances to approaching pedestrians than did non-incubating conspecifics, suggesting early escapes may function to help conceal the locality of the nest. No such effect was evident for Kentish Plover. [ABSTRACT FROM AUTHOR]

We developed diurnal time activity budgets to quantify parental behavior of American Oystercatchers ( Haematopus palliatus) breeding on the Texas Coast from February to July of 2013 and 2014. We conducted focal animal observations on breeding pairs for two reproductive periods: incubation and chick-rearing. We conducted observations on 60 nests and 38 broods for a total of 1,242 observational hours. American Oystercatchers predominantly engaged in incubation (52%), resting (16%) and self-maintenance (10%) during the incubation period. They predominantly engaged in resting (35%) and vigilance behaviors (29%) during chick-rearing. Agonistic behavior increased by 2% when adults were rearing chicks. We determined that breeding behavior was primarily partitioned between reproductive, self-maintenance, and vigilance behaviors. The life history of American Oystercatchers in the Gulf Coast region was poorly understood until recently, and this study provided insight on activity patterns and local factors influencing reproductive behavior. [ABSTRACT FROM AUTHOR]