Jabiru Stork (Jabiru mycteria is listed under Appendix I of CITES and considered threatened in Central America. The first population genetic analysis of Jabiru Storks was carried out using mitochondrial DNA (mtDNA) control region sequences (520 bp) and five heterologous microsatellite loci. Samples were collected from the field (N = 49) and museum skins (N = 22) in Central (mainly Belize, Nicaragua and Costa Rica) and South America (Colombia, Venezuela, Peru and Brazil). A decline of mtDNA diversity was observed in comparisons between past (N = 20) and present (N = 40) samples collected in Central America and northern South America. Similar levels of microsatellite loci diversity were observed among contemporary samples. Lower levels of mtDNA variability were observed in samples from Central America and northern South America when compared to the Brazilian Pantanal region. Significant levels of genetic differentiation were found between contemporary locations sampled, whereas non-significant results were observed for historic samples. The non-geographic association of haplotypes observed at the cladograms and the recent divergence times estimated between locations are indicative of an evolutionary history of a large population size with limited population structure. Reconnection of populations via increased gene flow, particularly in Central America, is recommended if genetic structure and status are to be restored.

The need for better understanding of migratory movements of wild birds in Asia promoted an evaluation of the usefulness of deuterium in feathers (δD_f) to assign origins. Feathers were sampled from Bar-headed Geese (Anser indicus), Whooper Swans (Cygnus cygnus), Mongolian Gulls (Larus vegae mongoliens), Curlew Sandpipers (Calidris ferruginea) and Pacific Golden Plover (Pluvialis fulva) in north-central Mongolia, from June to September 2007. Univariate statistical analyses were performed to test for differences between study sites for all species and between growing (blood) and previously grown (non-blood) feathers only for Bar-headed Geese. Values of δD_f in actively growing feathers generally agreed with those expected from integrated isotopic signals in precipitation expected for sampling sites. Values of δD_f from adult migrant birds also indicated varying degrees of movement from north to south expected from the movement of these species in Asia. These results show promise for the isotope approach for establishing origins of molt of migratory waterbirds in Asia in a cost-effective manner without the need for mark and recapture. Projects required to track movements of waterbirds in Asia could benefit by incorporating this approach into study design. However, greater refinement of the δD_f isoscape for Asia is now needed.

Information on when and where the Yellow-legged Gull (Larus michahellis Iusitanius) population breeding in northern Iberia moves throughout the year is lacking. Here, distances and directions of gull movements during their first year of life were elucidated. Data on 2,776 sightings of 728 out of 2,421 gulls banded as chicks in the southeastern Bay of Biscay were analyzed. Overall, most (69.2%) gulls were found less than 50 km from their natal colonies and practically all gulls (95.9%) were found along the coast of northern Iberia, confirming the low mobility of this Yellow-legged Gull population. Distances at which gulls were found did not vary with time, suggesting that stable feeding resources exist across the area used by the population.

Double-crested Cormorants (Phalacrocorax auritus) breeding in the Great Lakes and wintering in the southeastern United States were implanted with satellite transmitters to assess their movements. During 2007 and 2008, 26 cormorants from Georgian Bay, Ontario, Canada, were tracked in order to, variously, identify staging areas, characterize migration routes, winter habitat use, and home range size, assess philopatry of returning breeders, and test for a relationship between winter habitat use and arrival at the breeding ground. Females left summer areas earlier and spent more time in staging areas than did males. However, both sexes left the staging areas and arrived in the wintering grounds at approximately the same time. There was no difference in latitude between wintering males and females, or in winter residency time (n = 136 days for both sexes). The predominant winter habitat types were lakes and coasts with only seven of 26 (26.9%) birds wintering on aquaculture sites. Contrary to expectations, winter home ranges of birds on aquaculture sites ( = 2760 km²) were significantly larger than birds on non-aquaculture sites ( = 81 km²). A carryover effect of aquaculture was not detected; winter residency time was similar for birds on both aquaculture and natural winter habitats, with birds from both habitats returning north at the same time. Fidelity to the previous summer's location was observed in 15 of 20 returning individuals.

Foraging behavior, physiological state and site fidelity of resident (sedentary) and migratory American Dippers (Cinclus mexicanus) were compared to assess whether differences in over-wintering behavior or physiology explain the lower annual survival rate of resident individuals. Residents spent more time resting (23 vs. 14% of the time) and less time foraging (71 vs. 81% of the time) than migrants. However, there were no detectable differences in energetic intake (kJ/hr), foraging success (kJ/hr spent foraging), or physiological state (measured as size-corrected mass, hematocrit, leucocrit, total white blood cell count, and heterophil to lymphocyte ratio; immunoglobulin, triglyceride, and free glycerol levels; and total antioxidant capacity and total oxidative status of plasma). Foraging success, size-corrected mass and plasma triglyceride levels increased with date for both migrants and residents, indicating that both groups built up fat reserves as winter progressed. Resident individuals exhibited higher winter site fidelity than migrants (sighted on the same section of the river on 70 vs. 53% of weekly censuses). The lower site fidelity and, hence, greater movement of migrants may increase survival by allowing them to seek more suitable microhabitats during adverse conditions. Further work on the relationship between mortality rates, movement and winter home range size of migrant and resident dippers is needed to test the latter hypothesis.

Little is known about seabird distributions at night. Densities of Marbled Murrelets (Brachyramphus marmoratus, hereafter “murrelets”) and potential prey were determined along fixed-width transects in spring and summer of 2007 and 2008, and compared during night and day in two regions of Port Snettisham, near Juneau, Southeast Alaska. Murrelets moved from a shallower, more sheltered inner region, used during the day for foraging and staging for inland flights (2007 night densities = 15 ± 13 murrelets·km^-2; 2007 day densities = 172 ± 67 murrelets·km^-2), to a deeper, more exposed outer region, further from shore, during dark hours (2007 night densities = 113 ± 61 murrelets·km^-2; 2007 day densities = 41 ± 23 murrelets·km^-2). Prey school density and relative prey density were significantly higher at night in the inner region compared with the outer region (2.2 times higher prey school density and 3.8 times higher relative prey density), suggesting that murrelets were not redistributing themselves to forage on fish prey. A more likely explanation for why murrelets move from day use areas to night use areas is to avoid predators such as Bald Eagles (Haliaeetus leucocephalus), Great Horned Owls (Bubo virginianus) and various mammals.

The spatio-temporal structure of the waterbird community on the Mar Menor coastal lagoon (SE Spain) was analyzed in relation to environmental gradients from October 2006–March 2008. Waterbirds were censused at 20 sampling stations according to a zonation scheme based on degree of confinement and primary production, and subsequently modified to match bird use at the landscape level. Multivariate classification and ordination techniques (MDS and SIMPER) identified indicator species and displayed their association with environmental vectors. Abundance of waterbirds increased latitudinally, southward in winter and vice versa in summer. Greater abundance and diversity were found in the southern half of the lagoon in winter, where grebes, gulls and cormorants predominated, and in the northern half in summer, where gulls and terns were dominant. A latitudinal distribution of species was observed; the northern half characterized by Black-headed Gull (Larus ridibundus) and the southern half by Great-crested Grebe (Podiceps cristatus) and Great Cormorant (Phalacrocorax carbo). Such distribution patterns seem to respond to internal functional gradients of the lagoon as well as physical structure of the habitat and human activities. The results show that waterbirds can be incorporated into a monitoring scheme as integrative indicators of spatial gradients of environmental deterioration in the lagoon. In addition, the interpretation of ecological preferences and the response of waterbirds to environmental pressures can serve to assess the conservation status of species at local or regional scales, and act as a warning tool for changes in similar ecosystems.

To determine how habitat structural complexity, which affects prey vulnerability, influences foraging habitat selection by wading birds, a habitat use versus availability study was conducted throughout the Florida Everglades in 2005 and 2006. Also, an experiment was conducted where structural complexity was manipulated and its effect on wading bird foraging efficiency quantified. Among-year differences in habitat selection were found, which corresponded to disparate hydrological conditions. In 2005, a poor hydrological year in terms of the seasonal recession, wading birds chose foraging sites that had less emergent vegetation, a thicker flocculent layer and higher prey density relative to random sites. In 2006, an optimal hydrological year, wading bird foraging locations were similar to random sites in all aspects. Submerged vegetation did not affect wading bird site selection in either year. The study indicated that hydrological conditions that affect prey density were more important to wading bird foraging success than fine scale variation in habitat characteristics. However, in years of poor hydrology factors that affect prey vulnerability may become increasingly important because the penalty for choosing low quality foraging habitat is greater than in years of more optimal conditions. Elucidating habitat characteristics which create high quality foraging sites will be beneficial in planning wetland restoration projects and gauging future restoration progress.

Information on nest-activity patterns and energetic costs during the breeding season may shed light on current population trends of Great Egrets (Ardea alba). To address the issue, Great Egrets nesting in a mixed species colony in Wichita, Kansas, were studied from May–July in 2008 and 2009. A total of 35 h of scan samples at 28 random nests resulted in 5,062 instantaneous records; a separate 62 h of observations recorded 75 food-provisioning intervals. Adults at the nest engaged mainly in low-cost activities such as sitting, standing and preening, but activity patterns differed significantly by nest content. Adults with eggs spent significantly more time sitting but less time standing, preening or away from the nest. Overall variation in activity patterns among the 28 study nests was not significant. Food-provisioning intervals ranged from 6-480 min, with a median duration of 180 min. Intervals declined significantly with chick stage, were longer during periods of high wind velocity, and varied by time of day. Food-provisioning intervals for adults with eggs averaged >80 min longer than for those with chicks of all sizes. The results suggest that Great Egrets engage in low-cost activities and minimize energy costs while at the nest, and adjust the pattern of food-provisioning trips in response to proximate conditions and increased food demand.

Research on breeding American Oystercatchers has focused on identifying factors that affect reproductive success but little attention has been paid to parent behavior during chick-rearing. Parental attendance of American Oystercatchers was measured in Bulls Bay and along the Atlantic Intracoastal Waterway (Waterway) within the Cape Romain Region, South Carolina, USA, during 2006. Parental attendance rates averaged 90.9% in Bulls Bay and 81.4% along the Waterway. Daily survival of chicks was higher in Bulls Bay (0.989 ± 0.007) compared to the Waterway (0.966 ± 0.012). The extent of shellfish reefs (i.e. foraging areas) adjacent to nest sites was greater in Bulls Bay (5,633 ± 658 m²) compared to the Waterway (3,273 ± 850 m²). Mean parental attendance in Bulls Bay was higher for successful broods (90.5%) compared to failed broods (79.8%). In contrast, mean parental attendance along the Waterway was higher for failed broods (93.4%) compared to successful broods (67.5%). Less extensive shellfish reefs adjacent to nest sites along the Waterway appeared to require parents to depart more frequently to forage and the resultant reduction in attendance may have negatively affected chick survival. Bulls Bay may provide higher quality nesting habitat compared to the Waterway with respect to proximity to food resources and parental attendance. Management and conservation efforts for American Oystercatchers should consider the relationship between foraging and nesting habitat and variability in behavioral attributes, such as parental attendance, in relationship to environmental conditions which ultimately affect reproductive success.

Annual apparent survival rates from 323 marked immature Magnificent Frigatebirds (Fregata magnificens) were estimated using mark-recapture models for live encounter data in a six-year study (1998–2003) at Isla Isabel, the largest breeding colony in Western Mexico. A time and age immature apparent survival pattern was found: high and variable as yearling-juveniles (mean _1998–2000 = 9.78 ± 0.22) and, later, moderate and constant as juvenile-subadults and subadults (mean = 0.62 ± 0.11). Whereas resighting rate (p) increased with time (range = 0.00 [± 0.04] – 0.87 [± 0.11]). The results suggest variation in true survival and emigration during the juvenile life phase, high true survival and high site fidelity of juvenile-subadults and subadults during the interval after marking, and constant and either low true survival or high emigration in the subsequent intervals. Frigatebird apparent survival was predominantly higher in yearling juveniles than in subsequent age classes, an uncommon occurrence in other seabirds but likely with important demographic implications for species with long post-parental care and delayed maturity.

Breeding success of the Arabian/Indian race of the Western Reef Heron Egretta gularis schistacea was studied in the Hara Biosphere Reserve, Persian Gulf, during 2008 and 2009, with 103 and 137 nests studied, respectively. Marked nests were checked at least twice a week to note egg-laying date, clutch size, brood size, egg loss and chick mortality. Also, hatching and breeding success were estimated. Egg-laying was from 21 March to 17 April in 2008 and from 28 March to 28 April in 2009. Mean clutch size in the two years combined was 3.4 ± 0.05 and significantly greater in 2009 (3.5 ± 0.07) than 2008 (3.2 ± 0.07). Mean brood size was 2.0 ± 0.1 for all clutches and was greater in 2008. The internal diameter of nests, the height of nests from the ground and the distance of nests from the mangrove forest border were important factors influencing breeding success. The percentage of successful nests varied significantly between the two years (80% in 2008 and 51% in 2009). Overall, approximately 64% of nests were successful in producing at least one fledgling. Mean hatching and breeding success were 0.6 ± 0.02 and 0.5 ± 0.02, respectively. Both measures of success were lower in 2009 than in 2008, probably due to weather and egg predation by the Black Rat Rattus rattus which was responsible for about 50% of nest failures in the two years of the study. Mechanical control methods are suggested to reduce the negative effects of this rodent on breeding colonies of Western Reef Heron.

The Norwegian population of the nominate subspecies of Lesser Black-backed Gull, Larus fuscus fuscus, has declined strongly but the causes are unknown. The diet of these gulls breeding in two regions on coast of northern Norway was assessed over five years (2005–2009). In the southern region, chicks (n = 58) were fed predominantly gadoids (∼75% ABP [aggregated percentage of prey biomass] and ∼80% frequency; 70–130 mm length), probably saithe, Pollachius virens, whereas 0-group herring, Clupea harengus (40–50 mm length) accounted for ∼20% ABP and were fed to ∼20% of the chicks. In the northern region (n = 23), slightly larger 0-group herring comprised ∼60% of the prey mass and were fed to 65% of the chicks. In this area, gadoids and sandeel, Ammodytes spp., each accounted for ∼17% ABP of prey, and were fed to 20% and 30% of the chicks, respectively. Other species made up smaller proportions of chick diets. For adults, only regurgitated pellets (28 in the southern region) were available. Of 23 pellets from 2006 and 2007, 17 (74%) contained pipefish (probably Snake Pipefish, Entelurus aequoreus), whereas three contained herring, two gadoids, and one sandeel. In the poor breeding season of 2009, adult gulls also fed on blue mussels, Mytilus edulis, crabs (Brachyura), sea urchins (Echinoidea) and seabird eggs. Thus, Northern Lesser Black-backed Gulls are probably mainly piscivorous during breeding, and other prey are probably exploited only when fish are not readily available. Further, herring seems to be less important for L. f. fuscus than previously thought.

In the 1990s, flocks of tens of thousands of Razorbills (Alca torda), greatly outnumbering the local breeding population and, so of unknown origin were observed wintering off the island of Grand Manan, Bay of Fundy, Canada. To determine their origin, 39 radio transmitters were deployed on Razorbills at major breeding centers at Corossol Island (n = 10), Québec, the Gannet Islands, Newfoundland and Labrador (n = 15), and a colony near the overwintering area at Machias Seal Island (n = 14) in 2007. From January–March 2008, flights around Grand Manan detected 19 transmitter-fitted birds - twelve from Machias Seal Island, five from Corossol Island and two from the Gannet Islands. The findings confirm that Razorbills making up the wintering flocks off Grand Manan are not only local birds but also birds from major centers of the North American breeding distribution. Therefore, North American Razorbills from all breeding areas are vulnerable to mismanagement of the Bay of Fundy ecosystem, already degraded by over-exploitation and threatened by pollution from a variety of energy developments.

While conducting research examining the impact of American White Pelicans (Pelecanus erythrorhynchos) on the aquaculture industry in the southeastern United States, an apparent age and sex bias was observed among captured and collected pelicans. Data from 284 pelicans captured or collected at loafing sites located near aquaculture ponds during 1998 to 2009 were analyzed. A sampling bias could suggest segregation of pelicans by sex or age on wintering grounds. Captured pelicans were strongly biased towards immature males (73%) and collected pelicans were male biased (38% Adult Male, 47% Immature Male). Although the underlying mechanisms are not understood, observed pelican use of loafing areas may be related to numerous, readily available prey at aquaculture facilities.

American Coot (Fulica americana) behavior was observed and Water Hyacinth (Eichhornia crassipes) cover measured at Lake Chapala, Mexico, to determine whether site selection, habitat use, behavior within habitat types and selection of habitats for foraging were affected by the invasive aquatic plant. Water Hyacinth significantly affected habitat choice within selected sites but not site selection by coots. Coots spent less time in shallow water and more time in Water Hyacinth as site-level hyacinth cover increased. Water Hyacinth did not restrict coot movement and birds foraged significantly more in patch Water Hyacinth (28.7 ± 2.3% of total time) than in open water (9.8 ± 0.9%). Moreover, coots spent less time foraging in shallow water and more time foraging in hyacinths as cover increased. Coots used Water Hyacinth opportunistically and may have preferred it over other available habitat types. The positive relationships between Water Hyacinth and coots were likely attributed to the introduction of forage and refuge opportunities that were unavailable in Lake Chapala prior to Water Hyacinth invasion. Results suggest that efforts to control Water Hyacinth may indirectly affect the American Coot population.

Previous studies documented that Black Skimmers, Rynchops niger; tend to forage at night but did not examine which environmental variables explain nocturnal foraging. Foraging frequency and environmental variables were studied at a large breeding colony of skimmers on an urbanized barrier island on the west coast of Florida, USA. To determine which variables influenced foraging, the number of skimmers departing to forage was counted for 120, one-hour periods through the day and night from 30 May–29 August, 2007. Using generalized linear models, factors were most associated with skimmers departing to forage were identified. These models included: light level, temperature, wind, wind direction, relative humidity, tide height, tide stage (incoming, outgoing, or slack) and status of the colony (mostly eggs, chicks, or fledglings). Light level was the only factor to significantly influence the amount of foraging (Wald = 9.40, d.f. = 1, p = 0.002). The relationship was negative, as light levels decreased, the number of birds departing to forage increased. The average proportion of the colony foraging per hour at night was 38.2% (SE = 4.6) and during the day the average proportion was 13.6% (SE = 4.0). The likely cause is that small, planktivorous fish come closer to the surface and shoreline at low light levels, allowing the skimmer to employ its unusual foraging technique of “skimming”.