Birds are altering the phenology of critical life history events, including migration, in response to the effects of global climate change. Whooping Cranes (Grus americana) are one of the most critically endangered birds in the world. Their remnant population, referred to as the Aransas-Wood Buffalo Population, numbers between 300–400 individuals and migrates between the U.S. Gulf of Mexico coast and north-central Canada twice each year. Previous analyses suggested Whooping Crane migration was temporally constant in spring and fall. New analyses of observations spanning 1942–2016 show Whooping Crane migration is now occurring earlier in spring by approximately 22 days and later in fall by approximately 21 days. Spring temperatures have also increased in the migration corridor during the same period; however, there is no apparent temperature pattern during the fall. In spring, earlier migrating Whooping Cranes stopped over for longer periods of time compared to late-migrating cranes. This result may be partially explained by single Whooping Cranes migrating with earlier migrating Sandhill Cranes (Antigone canadensis). These results have important conservation implications as the timing of Whooping Crane migration and availability of the habitat and foraging resources, including those associated with agriculture, on which this species relies will be increasingly affected by climate change.

The American White Pelican (Pelecanus erythrorhynchos) is an iconic waterbird breeding in the Prairie Pothole and Upper Midwest Regions of North America. Significant variation in recruitment occurs among years. However, mechanisms affecting recruitment, such as variation in size at hatching and chick growth, have not been quantified. In this study, size at hatching and growth rates of American White Pelican chicks were examined at Mash Lake, Minnesota, USA, during 2010–2012. On the day of hatch, the mass and lengths of tarsus, wing and culmen were recorded for the oldest chick in 2-egg nests. No difference was detected in skeletal size at hatching during 2010–2012, but mass of chicks was 11% lower in 2010 than in 2011. Growth rates for mass and wing did not differ between 2011 and 2012, but over 40% of the variation in absolute and instantaneous (relative) growth rates of tarsus was explained by year, with higher rates in 2011; in 2011, nest initiations were started later than other years. Little variation in size at hatching or growth rates were detected between years, but significant variation in size at hatching and growth rates were detected within season depending on the timing of hatch. No difference was detected in initial mass throughout the nesting season, but initial tarsus and wing length were shorter in chicks hatched later in the season in 2012. However, absolute and instantaneous growth rates for mass, tarsus and wing were greater for late-hatched chicks in 2012, potentially allowing late-hatched chicks to fledge at an earlier age.

Brood reduction is a within-brood partial mortality due to sibling rivalry, and, in some species, the death of at least one sibling in the brood is almost guaranteed (obligate brood-reducers). Imperial Cormorants (Phalacrocorax atriceps) usually lay three-egg clutches that hatch asynchronously over 4–5 days. This species exhibits obligate brood reduction, and last-laid (marginal) eggs serve as insurance against early failure of elder (core) members. Within-brood sibling asymmetries were manipulated to analyze their effects on breeding success, brood reduction, parental body condition and chick growth. Two types of symmetrical broods containing three similar-sized chicks at the beginning of chick-rearing (3-days old) and close to the peak in brood reduction (8-days old) were generated to contrast the natural asymmetrical brood. Breeding success and parental condition were unrelated to sibling asymmetry levels. Asymptotic mass of fledglings from 8-day old broods was lower than those for natural and 3-day old broods. Our results suggest that hatching asynchrony favors early brood reduction and improves fledging condition. Regardless of asymmetry levels, Imperial Cormorants were obligate reducers, and the insurance value provided by the marginal chick was negligible. Therefore, the insurance value of the marginal offspring appears to serve mainly at the egg stage.

In recent decades, there has been increasing interest in the application of ecological indices to assess ecosystem condition in response to anthropogenic activities. An Index of Waterbird Community Integrity was previously developed for the Chesapeake Bay, USA. However, the scoring criteria were not defined well enough to generate scores for new species that were not observed in the original study. The goal of this study was to explicitly define the scoring criteria for the existing index and to develop index scores for all waterbirds of the Chesapeake Bay. The standardized index then was applied to a case study investigating the relationship between waterbird community integrity and shoreline development during late summer and late fall (2012–2014) using an alternative approach to survey methodology, which allowed for greater area coverage compared to the approach used in the original study. Index scores for both seasons were negatively related to percentage of developed shorelines. Providing these updated tools using the detailed scoring system will facilitate future application to new species or development of the index in other estuaries worldwide. This methodology allows for consistent cross-study comparisons and can be combined with other community integrity indices, allowing for more effective estuarine management.

An experimental approach was used to investigate wintering waterfowl responses to introduced trail use at foraging sites with and without recreational trails in California, USA. Waterfowl were exposed to trail use in the form of two researchers walking levees adjacent to ponded habitat, and the number of waterfowl by species were compared before and after experimental walks in 40-m bands starting at the levee and extending 200 m into the ponds. The researchers recorded distances to the nearest individuals, responses of focal animals, and numbers of recreational trail users. The most numerous species were Ruddy Duck (Oxyura jamaicensis), Northern Shoveler (Anas clypeata), and scaup spp. (Aythya affinis and A. marila). Recreational trail use rates at trail sites averaged 1 to 82 people/hr. The greatest difference in numbers of birds before vs. after experimental walks occurred in the two 40-m bands closest to the levee at non-trail sites (0–40 m [t = 4.558, P = 0.0001], 40–80 m [t = 3.775, P = 0.001]) and trail sites (0–40 m [t = 3.049, P = 0.005], 40–80 m [t = 1.808, P = 0.082]). The relationship between the ratio of beforeto after-walk waterfowl numbers vs. date since the start of the winter season (r² = 0.315, P = 0.102) and the total number of birds vs. the number of recreational trail users (r² = 0.041, P = 0.847) did not indicate increasing tolerance to trail use for waterfowl overall. However, species varied in their tolerances. Ruddy Duck numbers declined with increasing numbers of recreational trail users (rho = -0.481, P = 0.017), while Northern Shoveler numbers increased (rho = 0.456, P = 0.025). Distances (using the 95th percentile) that individual birds were recorded from researchers during experimental walks varied from approximately 170–200 m at both non-trail and trail sites.

Surveys for secretive marsh birds could be improved with refinements to address regional and species-specific variation in detection probabilities and optimal times of day to survey. Diel variation in relation to naive occupancy, detection rates, and vocalization rates of King (Rallus elegans) and Clapper (R. crepitans) rails were studied in intracoastal waterways in Virginia, USA. Autonomous acoustic devices recorded vocalizations of King and Clapper rails at 75 locations for 48-hr periods within a marsh complex. Naive King and Clapper rail occupancy did not vary hourly at either the marsh or the study area level. Combined King and Clapper rail detections and vocalizations varied across marshes, decreased as the sampling season progressed, and, for detections, was greatest during low rising tides (P < 0.01). Hourly variation in vocalization and detection rates did not show a pattern but occurred between 7.8% of pairwise comparisons for detections and 10.5% of pairwise comparisons for vocalizations (P < 0.01). Higher rates of detections and vocalizations occurred during the hours of 00:00–00:59, 05:00–05:59, 14:00–15:59, and lower rates during the hours of 07:00–09:59. Although statistically significant, because there were no patterns in these hourly differences, they may not be biologically relevant and are of little use to management. In fact, these findings demonstrate that surveys for King and Clapper rails in Virginia intracoastal waterways may be effectively conducted throughout the day.

Proposed oil and gas leasing in the National Petroleum Reserve - Alaska has raised questions about possible impacts of development on molting Greater White-fronted Geese (Anser albifrons frontalis) and their habitats. We used GPS transmitters to record fine-scale location data of molting and post-molt White-fronted Geese to assess patterns of movement and resource selection relative to vegetation class, year (2012, 2013), and body mass at capture. Molting White-fronted Geese were located an average of 63.3 ± 4.9 m (SE) from lakeshores. Estimated terrestrial home range size for flightless birds differed between years (2012 = 13.2 ± 2.6 km²; 2013 = 6.5 ± 1.8 km²), but did not vary among habitat strata or with body mass. Molting White-fronted Geese used sedge (Carex aquatilus) dominated low centered polygons and water more frequently than expected given proportional habitat availability, but avoided tussock tundra and wet sedge vegetation classes. Upon regaining flight, individuals tended to remain in the same general area, and the center of their home range only moved an average of 6.9 km. Greater White-fronted Geese that could fly tended to forage further from lakeshores ( = 245 m), and used a larger home range ( = 44.3 ± 9.5 km²) than when flightless.

Dam construction on the Zeya River, which is an important tributary of the Amur River in Far East Russia, has caused significant declines in water levels and frequency of floods in the adjacent floodplains since 1980. However, an extreme flood event occurred in 2013. Populations of six crane species were monitored before and after these drastic water level changes at Muraviovka Park in Far East Russia, an important breeding and stop-over site. Individuals were counted by territory mapping during the breeding season (2000–2015) and by roosting site counts during autumn migration (2006–2015). The objective of this study was to evaluate whether changes in water levels had a significant impact on local and migratory crane populations. We found a positive effect of flooding on numbers of breeding Red-crowned Cranes (Grus japonensis) and White-naped Cranes (Antigone vipio), as well as on numbers of roosting Hooded Cranes (Grus monacha) in autumn. Siberian Cranes (Leucogeranus leucogeranus) were only observed after the wetlands were flooded. The results of this study highlight the importance of elevated Amur River water levels for crane populations of global importance.

Eight Agami Herons (Agamia agami) captured in the Marais de Kaw-Roura National Nature Reserve in French Guiana were tracked with Argos satellite transmitters in 2012 and 2013. While nesting, birds used a 100- to 200-km² area around the colony site. After breeding, four birds moved from 280 to 1,250 km in different directions along the Atlantic coasts of Venezuela, Guyana, Suriname, French Guiana, and/or Brazil. Migration paths included one stop-over of 24 to 61 days. These results show that the Agami Heron uses large areas during the breeding season and can migrate long distances. That Agami Herons congregate from large areas into a limited number of potentially large colonies provides a basis for a conservation strategy for the species.

Eighteen polymorphic microsatellite loci were isolated and characterized from the endangered Black-fronted Tern (Chlidonias albostriatus), a species endemic to New Zealand. The loci were initially tested on seven individuals spanning the entire breeding range and then for a larger dataset of 345 samples covering 30 colonies from throughout the species' range. The number of alleles per loci ranged from 4 to 24, and observed and expected heterozygosity ranged between 0.46 and 0.95 and 0.45 to 0.86, respectively. One locus showed significant heterozygote deficit and appears to be sex-linked. The similar annealing temperatures across loci and the wide fragment sizes allowed multiplex polymerase chain reaction and rapid multilocus genotyping. The microsatellite markers will be useful tools for further investigation into the genetic diversity, population structure and effective population size of this endangered species and for informing conservation management.

Visually-oriented predators, such as seabirds, are highly light dependent, and thus their presence and activity under continuously dark conditions of Arctic polar night pose a number of questions about the strategies and mechanisms they use to find prey. Here, opportunistic observations of the behaviors of Thick-billed Murres (Uria lomvia; n = 4) and juvenile Black Guillemots (Cepphus grylle; n = 5) were made in the ocean around Spitsbergen Island, Svalbard Archipelago, off the coast of Norway. These observations were made between 15–23 January 2014–2017 during the darkest period of the polar night. Underwater observations recorded on 23 January 2014 and 19–20 January 2015 revealed that individual birds seemed to be attracted to artificial light. They actively foraged in the sea within the beam of scuba diver lights and harbor lamps indicating that artificial light may create additional feeding opportunities for seabirds present in the area. Other observations of Dovekies (Alle alle; n = 2) made on 15–16 January 2016 may indicate that not all seabird species exhibit such an adaptable behavior. Various seabird reactions might be caused also by different age and intra-specific variation among individuals; however, due to the limited number of observations, future studies are needed to increase our understanding of these behaviors.