The Tofino Wah-nah-jus Hilth-hoo-is Mudflats on Vancouver Island, British Columbia, Canada, include both pristine areas and sites with residential and resort development. Shorebird counts were conducted at six sites around these mudflats in 2011 and compared with historical counts from 1988, 1989, and 1995. Temporal trends of counts did not vary among sites with different levels of disturbance. Over the entire mudflats, counts of Dunlin (Calidris alpina) moving northward had a negative trend over time (β_yr = -0.04), as did counts of Western Sandpiper (Calidris mauri; β_yr = -0.04), Least Sandpiper (Calidris minutilla; β_yr = -0.03) and Short-billed Dowitcher (Limnodromus griseus; β_yr = -0.04) moving southward. In contrast, counts of Black-bellied Plover (Pluvialis squatarola; β_yr = 0.03) and Semipalmated Plover (Charadrius semipalmatus; β_yr = 0.02) moving northward increased over time. Counts of Dunlin and Short-billed Dowitcher were lower at disturbed sites relative to non-disturbed sites, indicating that disturbance may be displacing birds away from some sites. Further, counts of northward migrating shorebirds were negatively correlated with the presence of people and dogs at the most disturbed site (Chesterman Beach). Monitoring and precautionary actions to address effects of disturbance at this important stopover site are warranted.

Cormorants (Phalacrocoracidae) depend on their hind limbs (legs) to pursue prey underwater, rendering these structures critical for their survival. Assemblages of three or more species can be found in a variety of regions including the coasts of western USA (California), central Chile, and western South Africa. Cormorants all hunt via pursuit diving underwater while remaining close to shore, yet are able to coexist; an occurrence that is not well understood. Variation in feeding ecology within cormorant assemblages was expected to be reflected in the legs. Leg structure was examined by measurement of five leg bone characteristics from skeletal specimens of 10 species from assemblages within the aforementioned regions. Principle component analysis identified the femur and tarsometatarsus as having the highest degrees of variation. The femur was found to have the shortest length, relative to total leg length, in putative shoaling fish specialists. The tarsometatarsus was found to have the shortest length, relative to total leg length, in putative benthic fish specialists. Mantel's Test revealed that leg structures of members of the same putative feeding type were distributed closer together in Euclidean space (mean distance: 2.84) than leg structures of members of distinct putative feeding types (3.27); however, this was not significant (r = 0.138, t = 0.086, P = 0.233) indicating that similarity among assemblages is not statistically well-supported. Findings support niche differentiation within the studied regions.

Daily survival rate of Painted Stork (Mycteria leucocephala) nests from four different nesting colonies in northern India (Delhi Zoo, Keoladeo National Park, Chhata and Khanpur) were modeled as a function of multiple covariates. These included nest and colony specific parameters, year, daily maximum and minimum temperatures and sizes of foraging wetlands in the vicinity. A total of 1,095 Painted Stork nests (606 from 2013–2014 and 489 nests from 2014–2015) were monitored at an interval of 4–7 days during a study spanning two breeding seasons. Considerable variations were observed in annual nest survival due to the amount of rainfall and hence availability of suitable wetlands for foraging in the vicinity of the colony. Nest survival was strongly dependent upon nest age in that nests built early in the season had a higher survival probability (β_{Nest age} = 1.13, SE = 0.16). Daily survival rate was higher for nests located in high nest density colonies (β_{nest density} = 0.64, SE = 0.04). The additive effect of daily minimum temperature on the nest survival rate was positive (β_{Temp. min} = 1.21, SE = 0.26) indicating that lower temperatures in winter negatively influenced daily survival rate. Nest survival in Painted Stork is significantly affected by environmental factors like rainfall and daily minimum temperature, besides colony specific parameters such as nest density.

Numbers, densities, and sex ratios of Yellow Rails (Coturnicops noveboracensis) wintering at Red Slough Wildlife Management Area in McCurtain County, Oklahoma, USA, were approximated and compared to estimates from birds wintering in coastal Texas, USA. Deuterium (δD) and sulfur (δ³⁴S) values from rectrices of birds wintering in Oklahoma and in Texas were also examined to determine where the birds bred. Yellow Rails in Oklahoma from October 2009 through April 2010 were banded. Fifty-six Yellow Rails were captured, and the population was estimated to consist of 90.3 ± 25.5 birds, or 5.3 ± 1.5 rails * ha^-1, which is similar to the published density of Yellow Rails in coastal Texas. Sex ratios did not differ from an expected 1:1 male:female ratio and did not differ between Oklahoma and Texas. Rectrices from Texas (n = 40) and Oklahoma (n = 32) had similar δD values and were broadly consistent with published δD values from southeastern Alberta to James Bay in Ontario and Quebec, Canada. The δ³⁴S analysis from Texas (n = 4) and Oklahoma (n = 35) showed only two birds, both from Texas, with enriched δ³⁴S values, suggesting that most birds from Texas and Oklahoma bred in interior Canadian marshes. Although the sample size was small, these results suggest interior overwintering sites contain similar densities to coastal sites.

Habitat loss due to human development is a threat to colonial waterbird species, which require nesting habitat in proximity to productive aquatic foraging areas to ensure reproductive success. When development of habitat occurs, waterbirds must either tolerate the changes or relocate nesting colonies to habitat elsewhere. Land cover and nesting colony data were used to study the implications of development for the Pacific Great Blue Heron (Ardea herodias fannini). Colonies were closer to major foraging areas than expected by chance, but were not farther from human development than expected by chance, suggesting that Pacific Great Blue Herons will tolerate some development to remain close to major foraging areas. There was no relationship between distance to human development and colony productivity; however, distance to major foraging area was a significant predictor of productivity, which suggests Pacific Great Blue Herons may prioritize proximity to foraging areas because it is critical for reproductive success. Given their demonstrated preference for proximity to foraging areas, and high levels of development near these areas, relocation away from human development may not be an option for nesting Pacific Great Blue Herons in south coastal British Columbia, Canada, because potential nesting habitat availability was most restricted within 5 km of major foraging areas. Future management strategies for this species, and colonial waterbirds in general, should prioritize conservation of nesting habitat near major foraging areas to maximize future reproductive success.

The main goal of this study was to gain knowledge on post-release survival and movement of Western Grebes (Aechmophorus occidentalis) using a modified technique for implanting satellite transmitters. This technique had improved post-surgical survival in an earlier study. Nine Western Grebes, implanted with intracoelomic (within the body cavity) satellite transmitters with percutaneous antennae, were released close to their capture site in San Francisco Bay, California, USA. Eight survived at least 25 days (average number of transmittal days was 140.8), while two had transmitters that provided data for greater than 1 year (436 and 454 days). The average cumulative distance recorded for all Western Grebes (n = 9) was 829 km with two round-trip movements documented. One individual Western Grebe traveled a cumulative round-trip distance of 2,144 km in July and November 2011, while another individual traveled a round-trip distance of 1,514 km between 8 and 14 December 2011. This study provides a step forward in testing implantable satellite transmitters in Western Grebes and highlights the need to further improve tracking methods, potentially improving our understanding of their population threats.

The biology and behavior of Agami Herons (Agamia agami) are not well known. This paper describes the species' foraging, nesting, plumage, soft-part coloration, courtship, and disturbance response studied during a 28-hour 8-day study period, 11–18 May 2015, in Costa Rica. Agami Herons forage by standing on perches and walking or wading slowly, capturing small prey using a slow neck extension followed by a grasp. Courtship emphasizes its spectacular, short-lived silver crest and other similarly distinctive plumage and soft-part features. Thirteen courtship behaviors described are used by both sexes. The female, rather than the male, retains intense red lores during pair formation. Only two nest change-overs and no chick feeding were observed, which, along with evidence of distant foraging, suggest a nesting strategy accommodating long intervals between chick provisioning. Agami Herons respond to disturbance with a rattling call and by walking away into vegetative cover. This observed sensitivity to disturbance reinforces a conservation strategy for the species emphasizing protection of regionally important nesting colonies and their foraging habitat.

Capturing breeding adults of colonially nesting species can entail risks of nest failure and even colony abandonment, especially in species that react strongly to human disturbance. A low-disturbance technique for capturing specific adult Double-crested Cormorants (Phalacrocorax auritus) at a ground-nesting colony was developed to reduce these risks and is described here. Nesting habitat enhancement was used to attract Doublecrested Cormorants to nest adjacent to above-ground tunnels constructed so that researchers could capture birds by hand. Using this technique, Double-crested Cormorants (n = 87) were captured during the incubation and chick-rearing stages of the nesting cycle. Unlike alternative capture techniques, this approach allowed targeting of specific individuals for capture and recapture, minimized local disturbance, and eliminated colony-wide disturbances. The tunnel-based system presented here could be adapted to capture adults or to access the nest contents of other ground-nesting colonial species that are inclined to nest in areas of enhanced nesting habitat and adapt to anthropogenic structures in their nesting area. This system would be particularly beneficial for other wary and easily disturbed species.

Small-scale environmental characteristics associated with nesting burrows of the Newell's Shearwater (Puffinus newelli) and Hawaiian Petrel (Pterodroma sandwichensis) were documented in mesic and wet montane forest on the island of Kauai, Hawaii, USA. Most plots containing burrows were located on steep slopes, ranging from 28° to 48° (median = 39°) for the Newell's Shearwater and 0° to 67° (median = 34.5°) for the Hawaiian Petrel. Plots generally contained > 20% to 40% up to > 80% to 100% estimated vegetation cover 0–1 m above ground and > 0% to 20% up to > 60% to 80% cover 1–2 m above ground. Plots were also associated with estimated canopy cover from > 0% to 10% up to > 80% to 90% for the Newell's Shearwater and 0% up to > 70% to 80% for the Hawaiian Petrel. Soil in Newell's Shearwater plots tended to be harder 7.62–22.86 cm below ground, which might provide increased burrow stability. Additionally, maximum vegetation height tended to be greater above Newell's Shearwater plots (median = 6.00 m) than Hawaiian Petrel plots (median = 3.25 m). Taller trees may serve as climbing structures helping Newell's Shearwaters become airborne in thickly vegetated regions that are farther from ridgelines and associated with lighter wind speeds aloft.

Intraspecific and intersexual morphological variation is common in many groups of birds, but few studies with larger sample sizes exist for describing such variation in ardeids. Since 2008, three species of long-legged wading birds were captured for telemetry studies in Wichita, Kansas, USA, and on the East Coast of the USA in North Carolina, Maryland, and New Jersey. Captured individuals were weighed and their culmens and tarsi were measured before they were released. Beginning in 2013, a blood sample was collected from each bird and was used to determine its sex. Measurements of 103 birds of three species were used to examine statistical relationships among mass, culmen length, and tarsus length, and to determine whether males of Great Egrets (Ardea alba) and Snowy Egrets (Egretta thula) differed from females in these values. Great Blue Herons (A. herodias; 1,702–2,859 g), Great Egrets (769–1,300 g), and Snowy Egrets (349–539 g) all showed high variation in body weights, but significantly lower variation in culmen and tarsus lengths. For all three species, body weight correlated significantly with both culmen and tarsus lengths, which were themselves strongly associated. Male Great and Snowy egrets were significantly heavier than females and also had longer culmens and tarsi. The role of interspecific differences in body size in reducing competition at feeding sites is discussed, as is the possible role of intersexual differences during the breeding season.

North American migratory shorebirds have declined markedly since the 1980s, underscoring the importance of population surveys to conduct status and trend assessments. Shorebird surveys were conducted during three multi-year periods between 1985 and 2014 and used to assess changes in numbers and species composition at the Cabo Rojo Salt Flats, Puerto Rico, USA, a site of regional importance in the eastern Caribbean. Eight fewer species (total = 21) were recorded in 2013–2014 as compared to the 29 from 1985–1992; all eight species were Nearctic migrants. Small calidrids had the highest population counts; however, this suite of species and all others experienced a ≥ 70% decline. Combined counts from the salt flats and neighboring wetlands in 2013–2014 were lower than counts only from the Cabo Rojo Salt Flats in two previous multi-year survey periods, which indicated a real change in numbers not just a shift in wetland use. Invertebrate prey density was lower in 2013–2014 than in 1994. Body fat condition of Semipalmated Sandpipers (Calidris pusilla), an index of habitat quality, did not differ between 1985–1992 and 2013–2014. These findings do not exclude the possibility that other species might be affected by lower prey density, or that local declines in numbers reflect changes at hemispheric, not local, scales. The magnitude of change between local and hemispheric scales closely matched for some species. Continued monitoring at the salt flats is warranted to help gauge the status of shorebirds in Puerto Rico and discern the probable cause of declines. Monitoring other sites in the Caribbean is needed for stronger inferences about regional status and trends.

The Lesser Crested Tern (Thalasseus bengalensis) is a ground-nesting seabird that breeds only on subtropical and tropical islands from northern Africa to northern Australia. Despite their wide distribution, few studies have been conducted on the breeding ecology of this species. On Jana Island, Saudi Arabia, which is northeast of the Saudi Arabia mainland, the midday ground temperature may reach 60 °C during the summer. In this study, two cameras were used to record the incubation behavior of Lesser Crested Terns to evaluate their coping ability in this extremely hot environment. The behavioral mechanism that the seabirds used to maintain optimal egg temperatures was also evaluated. The results show that Lesser Crested Terns attend their eggs continuously during a 24-hr period without leaving the nests, except when a disturbance occurs. This behavior prevents the eggs from reaching lethal temperatures. In addition, position of the sun influenced the incubation behavior. Most incubating Lesser Crested Terns faced west in the morning, and began rotating clockwise until they faced east in the evening. This behavior may play a vital role in preventing both eggs and incubating adults from overheating.