Modeling habitat selection of species with specific foraging requirements is an effective means to evaluate landscape quality for restoration and conservation purposes. Proportional hazards regression, a discrete choice model, was used to develop resource selection functions for breeding Wood Stork in the southern Everglades during the 2006 nesting season. Wood Storks showed the highest probability of habitat selection in a narrow range of shallow water depths. The quadratic form of water depth (depth depth2) was an important indicator of habitat selection with mean water depths between -25 and 25 cm receiving the highest probability of use (a negative water depth is below average ground elevation). Foraging sites within 20 km of nesting colonies were selected over farther sites. Shrub swamp, mangrove swamp and saltwater marsh vegetation types were used in higher proportions than they occurred in the landscape. Results exemplify the importance of shallow water depths near established stork breeding colonies throughout the breeding season.

Wetland-scale and landscape-scale descriptors were compiled at 123 wetlands where Least Bittern (Ixobrychus exilis) have been detected in Québec since 1986 to identify key attributes associated with Least Bittern occurrence. Land cover information extracted from Landsat-7 ETM imagery and road density were calculated for a 500-m buffer surrounding occupied wetlands and paired sites ten km away to compare to the regional landscape. Cattail (Typha spp.) was the dominant vegetation at 96 of 123 wetlands. Shrub swamps were used at eleven sites. Wetland area ranged from 0.5 ha to 983 ha and man-made impoundments accounted for 24% of occupied sites. The 500-m buffer surrounding occupied wetlands was dominated by urban areas, agriculture, forests or wetlands at four, 22, 21 and 32 sites, respectively. Mean wetland cover was higher in the 500-m buffer (37%) than in the regional landscape (4%) whereas agriculture cover was greater at paired sites (55%) than around occupied wetlands (28%). Cover of anthropogenic and forest areas did not differ between wetland buffers and paired sites. Mean road density was higher in the 500-m buffer around occupied wetlands (29.5 m/ha) than in the regional landscape (18.4 m/ha) suggesting that wetlands near roads may be more easily accessible to surveyors. Habitat use in Québec corresponds with known breeding habitat structure elsewhere in North America. Along with wetland creation and conservation initiatives of remaining small and large wetlands, Least Bittern conservation will benefit from regular monitoring of impoundments' operable conditions to prevent sudden habitat changes that may impact breeding birds.

The Whimbrel (Numenius phaeopus) is one of a suite of sub-arctic- and arctic-nesting shorebirds for which encroachment of woody vegetation into previously open habitats may cause a reduction in breeding habitat. Whimbrel nesting habitat selection was studied at two spatial scales near Churchill, Manitoba, Canada, to determine habitat preferences and the degree to which the species avoided woody vegetation. Whimbrels occupied sites at the mesohabitat (territory) scale characterized by either high lichen cover, or high graminoid and standing water cover. No Whimbrels nested in mesohabitat with >17.5% tall shrub cover, and only one pair nested where >38 trees existed within 30 m of the nest. At the microhabitat (nest) scale, Whimbrels nested in two distinct habitats. In lichen-dominated sites, nests had less concealing vegetation than unused sites whereas in graminoid dominated habitats, nests were more concealed than unused sites. Sixty-eight percent of nests were on hummocks or lichen ridges. Hatching success was not predicted by habitat characteristics and was lower than previously reported (2007: 26%; 2008: 14%). Avoidance of woody vegetation by breeding Whimbrels suggests that shrub and tree encroachment would reduce habitat availability in the Churchill region.

Most studies of King Rail (Rallus elegans) have investigated habitat use during the nesting season, while few comparisons have been made between the nesting and brood-rearing seasons. King Rails were located during the nesting season in Missouri using repeated surveys with call playback, and systematic searches for broods were conducted during the brood-rearing season. King Rail adults were located at twelve points in 2006 and 14 points in 2007, and five King Rail broods were located in each year. Water depth was measured and dominant cover type determined for randomly sampled 5-m plots within used and unused habitats. Logistic regression models were fitted to the data and top models were selected from the candidate set using AIC_c. Nesting adults occurred more often in areas dominated by short (≤1 m) emergent vegetation ( = 0.77 ± 0.27) and deeper water ( = 0.05 ± 0.02). Broods occurred more often in areas dominated by short emergent vegetation ( = 1.19 ± 0.37) and shallow water ( = -0.17 ± 0.06), and avoided areas dominated by tall (>1 m) emergent vegetation ( =-1.15 ± 0.45). A modified catch-curve analysis was used to estimate chick daily survival rates during selected 7-day periods for each year. Daily survival rate ranged from 0.92 ± 0.008 in late June 2007 to 0.96 ± 0.005 in late July 2006. Management plans for King Rails should include the different habitat types needed during the nesting and brood-rearing stages.

Increasing populations of Double-crested Cormorants (Phalacrocorax auritus; hereafter cormorants) are of concern regarding the displacement of other species from breeding colonies, but little is known about such interactions. Agonistic interactions between ground-nesting cormorants and American White Pelicans (Pelecanus erythrorhynchos; hereafter pelicans) were investigated and compared to those involving cormorants and Herring Gulls (Larus argentatus). Also, a survey of cormorant eggs in nests of other ground-nesting species was conducted. Of 158 agonistic interactions between cormorants and pelicans, 83% were threat displays, 9% attempts to steal nest material and 8% involved some form of physical contact. Pelicans defended their nests less frequently and engaged in fewer physical contacts (8%) in colonies mixed with cormorants compared to areas with only pelicans (33%). Herring Gulls engaged in more physical contact (26%) with cormorants in a mixed colony than when nesting only with other gulls (4%). Cormorant eggs were found in 1–26% of Herring and Ring-billed Gull (L. delawarensis) nests searched in the Great Lakes, and 0.3% of Caspian Tern (Hydroprogne caspia) nests at one location. The results indicate cormorants routinely engage in agonistic interactions with other ground-nesting birds; however, the type and importance of interactions varies. Site- and species-specific evaluation of interactions involving cormorants and other birds is recommended before taking management steps to reduce nest site competition.

Thousands of Black Brant (Branta bernicla nigricans) migrate annually to the Teshekpuk Lake Special Area (TLSA), Alaska, to undergo the flightless wing molt on tundra lakes and wetlands. GPS transmitters were attached to Brant over two summers (2007–2008) to examine patterns of movement and habitat use of molting Brant, including variation by habitat type, year and body mass. Molting Brant were located an average of 31 ± 1 m (SE) from shore and this distance did not vary across any of the explanatory variables. Brant moved an average of 123 ± 3 m hr^-1 while flightless. Movement rates varied by year, averaging 22 ± 12 m hr^-1 faster in 2008, and across habitat types, averaging 22 ± 13 m hr^-1 faster in inland versus coastal and estuarine habitats. Two kernel home ranges were estimated: entire home range, which encompassed the complete 95% probability contour, and shoreline home range, which included only shoreline areas used by molting Brant. Entire home range (x bar = 15.1 ± 2.2 km²) was negatively correlated with body mass, suggesting that heavier individuals have more body reserves to contribute to feather growth and thereby require less food and smaller home ranges. Conversely, shoreline home range (x bar = 4.3 ± 0.6 km²) did not vary by body mass, but rather by habitat type, being larger in estuarine habitats. The complex shorelines and numerous deltaic islands of estuarine habitats offer more shoreline per area than either coastal or inland habitats. Brant appear to have limited ability to adjust their home range size or forage further from shore in response to variable food resources across years or habitats, instead altering their movement rate. Given this apparent lack of behavioral flexibility, Brant may be sensitive to development-related disturbances or habitat losses at molt sites in the TLSA.

The lower Mississippi Alluvial Valley (hereafter LMAV) provides winter habitat for approximately 40% of the Mississippi Flyway's Mallard (Anas platyrhynhcos) population; information on winter survival rates of female Mallards in the LMAV is restricted to data collected prior to implementation of the North American Waterfowl Management Plan. To estimate recent survival and cause-specific mortality rates in the LMAV, 174 radio-marked female Mallards were tracked for a total of 11,912 exposure days. Survival varied by time periods defined by hunting seasons, and females with lower body condition (size adjusted body mass) at time of capture had reduced probability of survival. Female survival was less and the duration of our tracking period was greater than those in previous studies of similarly marked females in the LMAV; the product-limit survival estimate (±SE) through the entire tracking period (136 days) was 0.54 ± 0.10. Cause-specific mortality rates were 0.18 ± 0.04 and 0.34 ± 0.12 for hunting and other sources of mortality, respectively; the estimated mortality rate from other sources (including those from avian, mammalian, or unknown sources) was higher than mortality from non-hunting sources reported in previous studies of Mallards in the LMAV. Models that incorporate winter survival estimates as a factor in Mallard population growth rates should be adjusted for these reduced winter survival estimates.

The interaction of aerial predators and migrant Semipalmated Sandpipers (Calidris pusilla) was studied at Mary's Point in the upper Bay of Fundy, New Brunswick, Canada, during August of 2009 and 2010. Peregrine Falcons (Falco peregrinus) were locally reintroduced and increased from one active nest site in 1989 to 27 in 2010, which coincided with a decline of sandpipers roosting at Mary's Point from an annual mean of 161,000 in 1976–1982 to 15,000 or less during this study. Mean roosting time of flocks was 33 min (range = 10 to 40 min; N = 6). Sandpipers returned to the beach 1 h:36 min after high-tide (range = 1 h:10 to 2 h:13 min; N = 5), but were soon flushed again by falcons. On ten of 19 days, during part of the high-tide period, flocks of sandpipers remained in flight over the ocean. Termed Over-Ocean Flocking (OOF), this behavior was seen on days when spring tides inundated all beach habitat, and also at lower tides, which supports the hypothesis that OOF is an antipredator strategy intended to avoid surprise attacks by falcons near the shore. Raptors sighted during 128 hours afield included 226 Peregrines, 20 Merlins (Falco columbarius) and two Sharp-shinned Hawks (Accipiter striatus). At 1.0–3.2 Peregrine sightings/h^-1 (mean 1.8) the level of disturbance is high and supports the hypothesis that the decline in roosting sandpipers at Mary's Point is linked to predation danger.

After near extirpation in the early 20th century, Ring-billed Gulls (Larus delawarensis) are currently (2009) the most abundant colonial waterbird nesting on the Great Lakes. Nest count data are reported from four decadal censuses (1976–2009) conducted by the Canadian Wildlife Service and the U.S. Fish and Wildlife Service. Numbers increased from 305,790 nests (1976–80) to a peak of 718,887 nests (1989–90), then decreased to 652,664 (1997–2000) and to 585,984 nests (2007–09). Changes varied spatially after the second census with greatest losses (-38.6%) at North Channel, Georgian Bay and northern Lake Huron colonies, and greatest gains ( 324.2%) at Lake Michigan colonies. A total of 472 sites had nests in at least one census (Canada N = 319; U.S. N = 153). Eighteen (3.8%) colonies had >2,000 nests in all four censuses, and had 37.5–41.9% of all nests in each census. Site occupancy was fluid. A high proportion (56.8%, N = 268) of sites contained nests in only one of the four censuses, and few (N = 40, 8.5%) had nests in all censuses. Thirty-nine sites had >2,000 nests gains/losses between census periods; 14 (35.9%) were on urban/industrial lands with artificial substrates. Human management and predator activities at some colonies contributed to declines in nest numbers at these locations. Movement of breeding birds among colonies and changes in local food supply may have influenced changes in nest numbers elsewhere. Reasons for the overall nest losses across the Great Lakes after the second census are unknown.

The Commonwealth of the Bahamas is an important region to Reddish Egrets (Egretta rufescens); however, current status of this species in the Bahamas is lacking. From 2008–2010, a breeding survey of Reddish Egrets was conducted in Great Inagua to 1) document breeding status, 2) document breeding phenology, and 3) estimate the number of breeding pairs. A total of 87 Reddish Egret nests on Great Inagua over two breeding seasons were recorded; the proportion of white, dark and mixed-morph nesting pairs varied but averaged (±S.D.) 68.4 ± 7.5, 18.2 ± 2.4, and 13.4 ± 5.1%, respectively. Based on these surveys, the breeding season range extends from December to May, varying annually due to changes in precipitation. Territorial aggression of solitary nesting pairs in Reddish Egrets was observed, previously unreported for the Caribbean. Damage to mangrove islands from Hurricane Ike in September 2008 appeared to increase nesting concentrations on Lake Rosa; solitary nesting decreased from 36% before, to 10% after the hurricane. Because the surveys before and after the hurricane did not encompass the entire breeding seasons, increased concentration of nesting may have been influenced by other factors besides Hurricane Ike. Even with incomplete breeding season surveys, these estimates of nesting pairs indicate a >50% decrease in number of breeding pairs of Reddish Egret on Great Inagua since the 1980s; this is a conservation concern as the population is distinct.

American White Pelicans (Pelecanus erythrorhynchos) are reported to consume large quantities of commercial catfish in Alabama, Arkansas, Louisiana and Mississippi, negatively impacting aquaculture production. If pelicans consume a single item diet, such as catfish, nutritional deficiencies may result. Therefore, effects of mono-and multi-species diets were examined to determine nutritional impacts on pelicans in addition to determining if preferences for certain fish species exist. Twelve American White Pelicans captured in northwest Mississippi were used for a seven day metabolism trial followed by a two day preference trial. In the metabolism trial, pelicans were assigned to one of three treatment diets (four birds/diet): catfish only, carp only, or both (50% catfish and 50% carp). Pelicans consuming only catfish metabolized less dry matter, organic matter and energy than those consuming only carp or both. Four pelicans were used to determine preference for carp or catfish. Pelicans ate more (P = 0.001) carp (89% of diet) and digested nutrients from carp more efficiently than they did from catfish. Pelicans can meet nutritional requirements by consuming a mono-species diet of fish; however, certain prey may be more beneficial and even preferred for consumption.

The Least Bittern (Ixobrychus exilis) is at risk in several regions of North America and the effectiveness of multi-species marsh bird surveys to detect this secretive species has been questioned. A species-specific standardized survey protocol for Least Bitterns was developed to increase detection, quantify detection probability and improve knowledge of the species' distribution, abundance and habitat use. The protocol is a modification of the Standardized North American Marsh Bird Monitoring Protocol (Conway 2009), whereby only the Least Bittern call is broadcast repeatedly at fixed point count survey stations, and a second passive listening period is added after the broadcast period to increase detection. Vocalizations and behavior are noted on a minute-by-minute basis for each individual Least Bittern, along with estimated distance at first detection. The protocol has been implemented in Canada since 2006 and has resulted in Least Bitterns being detected in more sites and larger numbers than previously suspected. Adoption of the proposed protocol is recommended across the Least Bittern range when Least Bittern detection is the focus of a survey or monitoring program; therefore allowing direct comparisons of relative abundance and detection probabilities amongst sites.

The relationship between breeding site characteristics and breeding parameters of Little Egrets were investigated in the Sfax salt marshes (salina), Tunisia. Thirty colonies distributed among 14 breeding sites were monitored weekly during four breeding seasons (2004–2007). The number of breeding pairs varied among years in parallel with the number of detected colonies. Regressions were used to assess whether breeding site surface area, vegetation cover and inaccessibility to terrestrial predators affected the size and reproductive success of the colonies. Colony size was positively related to breeding site surface area and vegetation cover, while site isolation was the most important predictor of chick productivity. The results suggest that Little Egret colony size in the Sfax salina is determined by availability of nesting places, while chick productivity is controlled by accessibility of breeding sites to terrestrial predators, i.e. dogs. Given these results, an effective management action to conserve Little Egrets in Sfax would be to strategically place fences to protect large and densely-vegetated islets from these predators.

Although Sandhill Cranes (Gras canadensis) are considered as threatened in Mexico, there are no details on either their present winter distribution or descriptions of wetlands where cranes have been recorded. The objective here was to update the location of their wintering areas in Mexico and characterize the wetlands where they roost in winter. The wetlands were surveyed by ground and air, covering the Chihuahuan Desert in the states of Chihuahua, Coahuila, Nuevo León, Durango, San Luis Potosí, Zacatecas and Guanajuato. Sandhill Cranes were recorded in 31 wetlands, of which 13 were new locations and extended the present distribution 237 km south. Three possible hypotheses, acting either individually or in combination, are proposed to explain the new locations. The main threats to the wetlands are their proximity to urban centers, disturbances to roosting areas due to human activity and land-use change. Some wetlands where cranes have been recorded had not been considered as priorities for waterfowl but would have importance for cranes and other species during migration and winter. Further studies of crane migration and wintering are important for conservation and management of the wetlands.

Nestling diets of the vulnerable Chinese Egret (Egretta eulophotes) were analyzed at two breeding colonies on islands off Fujian, Southern China, in 2007 and 2008. Fish and shrimps were the main prey, comprising 87.5% and 35.4% by frequency of occurrence in regurgitations, respectively. Prey in the 4–6 mm size class occurred most commonly (80.4% of regurgitations). Compared with nestling diets of the Little Egret (Egretta garzetta) from other island heronries, nestlings of the Chinese Egret depended on prey that only occurred in coastal wetlands, whereas nestlings of the Little Egret consumed prey found in all aquatic habitats, including freshwater marshes; however, both species preyed on fish and shrimps and took prey of a similar size. The results suggest that coastal wetlands near the heronries need to be considered in habitat conservation for Chinese Egret.

A system was developed for the delineation of distance intervals in front of an observer during seabird surveys. Delineation is based on a coordinates system (x.y) with the vanishing point on the horizon being the origin (0:0), within a vertical plane in front of the observer. Coordinates of parallel interval limits can be calculated using y = H x/d_p (H = height of the observer's eyes; d_p = perpendicular distance between transect centerline and interval limit), and coordinates of radial interval limits using (w_p = distance between the observer and the vertical plane in direction of interval limit; d_c = observer's distance to the interval limit). The use of the delineation system will help reduce observer-induced variation in seabird at-sea surveys.