A framework for a sampling plan for monitoring marshbird populations in the contiguous 48 states is proposed here. The sampling universe is the breeding habitat (i.e. wetlands) potentially used by marshbirds. Selection protocols would be implemented within each of large geographical strata, such as Bird Conservation Regions. Site selection will be done using a two-stage cluster sample. Primary sampling units (PSUs) would be land areas, such as legal townships, and would be selected by a procedure such as systematic sampling. Secondary sampling units (SSUs) will be wetlands or portions of wetlands in the PSUs. SSUs will be selected by a randomized spatially balanced procedure. For analysis, the use of a variety of methods as a means of increasing confidence in conclusions that may be reached is encouraged. Additional effort will be required to work out details and implement the plan.

A large proportion of the Hudsonian Godwits (Limosa haemastica) spending the boreal winter along the eastern Pacific Ocean coast are known to occur in the vicinity of Chiloé Island, Chile, but the importance of the region to Whimbrels (Numenius phaeopus) is less known. Ground counts conducted in 2007 and 2008 increased published estimates, at a minimum, of Pacific coast populations by 27% for Whimbrels (33,150 individuals) and 51% for Hudsonian Godwits (21,161 individuals). Bays and shorelines in the Chiloé Island region supported 99% of Hudsonian Godwits and, perhaps, 61% of Whimbrels estimated to occur along the Pacific coast during the boreal winter. Whereas Hudsonian Godwits aggregated in shallow bays on the eastern and northern coast of Chiloé Island, Whimbrels were more dispersed along the island's coastline and reached a density of 7.5 birds/km along sheltered gravel shorelines. Bays in the vicinity of Chiloé's capital, Castro, provided important foraging and roosting habitat for non-breeding birds; these sites supported 52% of the Pacific coast population of Hudsonian Godwits and >4,000 Whimbrels. Low human disturbance in Pullao and Putemún bays makes these sites particularly attractive to nonbreeding Hudsonian Godwits, and their permanent protection is urged.

Patterns of spatial and temporal variation in species richness, abundance and diversity were evaluated in eight wetlands in Central-South Chile in relation to nine wetland characteristics. Twenty-six bird species were recorded, among the most representative families were Rallidae, Ardeidae and Anatidae with five species each. Stepwise regression analyses identified wetland area and water level fluctuations as the most important variables determining bird abundance. Variations in species richness were explained by wetland area, shoreline length, vegetation cover and water-level fluctuations. Shoreline development, shoreline length and wetland area lower than one-meter depth were especially important in determining species diversity. Cluster analyses showed similar results. Shoreline length was an important feature influencing total species number, but simple regression analysis showed that the species area relationship occurs in wetlands too. This study concludes that species richness, bird abundance and diversity reach higher values in larger and structurally more heterogeneous wetlands, but with important seasonal dynamics in waterbirds. The relationships between habitat characteristics and community structure did not remain unchanged throughout the year, suggesting that the birds respond differently to one or another habitat characteristic depending on the season. These results show the need for wetland conservation in Chile, paying special attention to the largest and most heterogeneous wetlands to conserve the greatest species richness and bird abundance.

A study, using satellite telemetry, was conducted to determine the precise migration patterns and wintering locations of Common Loons (Gavia immer) breeding in the northeastern United States. Transmitters were implanted in 17 loons (16 adults and one juvenile) that were captured on breeding lakes in New York, New Hampshire, and Maine during the summers of 2003, 2004, and 2005. Transmitters from ten of the birds provided adequate location data to document movement to wintering areas. Most adult loons appeared to travel non-stop from breeding lakes, or neighboring lakes (within 15 km), to the Atlantic coast. Adult loons marked in New Hampshire and Maine wintered 152 to 239 km from breeding lakes, along the Maine coast. Adult loons marked in the Adirondack Park of New York wintered along the coasts of Massachusetts (414 km from breeding lake), Rhode Island (362 km), and southern New Jersey (527 km). Most of the loons remained relatively stationary throughout the winter, but the size of individual wintering areas of adult loons ranged from 43 to 1,159 km², based on a 95% fixed kernel utilization distribution probability. A juvenile bird from New York made a number of stops at lakes and reservoirs en route to Long Island Sound (325 km from breeding lake). Maximum functional life of transmitters was about 12 months, providing an opportunity to document spring migration movements as well. This work provides essential information for development and implementation of regional Common Loon conservation strategies in the Northeastern U.S.

The conservation of wading birds is increasingly dependent upon determining the ability of human-modified habitats to serve as surrogates for natural habitats. The suitability of commercial shrimp farms and seminatural estuarine mudflats in Northwest Ecuador as foraging habitat for wading birds was assessed by observing the foraging efficiency, diet and behavior of Great (Ardea alba) and Snowy (Egretta thula) Egrets, censusing wading birds, and measuring prey availability (i.e. prey density, standing crop, water depth and diversity). Mean annual wading bird density was greatest in shrimp ponds, but was greater on mudflats during the breeding season when energy demands are most critical. Foraging efficiency (capture/strike) was greater on average in shrimp ponds than on mudflats, and both Great and Snowy Egrets captured significantly larger prey items (in both length and mass) there than on mudflats. However, intake rates (g/minute) were significantly greater on seminatural mudflats than in shrimp ponds during the breeding season. Prey standing crop, mass of individual prey items and water depths were all significantly greater in shrimp ponds than on mudflats, while the opposite was true for prey density and diversity. Shrimp ponds provide important foraging habitat for Great and Snowy Egrets, particularly during harvest events and during the non-breeding season, while four other wading bird species (Tricolored Heron (Egretta tricolor), Little Blue Heron (Egretta caerulea), Yellow-crowned Night Heron (Nyctanassa violacea) and Striated Heron (Butorides striatus)) were precluded from foraging in most ponds due in part to deeper water (>30 cm), pond bathymetry, larger prey items and differing foraging behaviors. While important to Great and Snowy Egrets, shrimp ponds do not appear to provide suitable foraging habitat for all other diurnal wading bird species within the local community, and do not likely serve as complete ecological substitutes for natural foraging habitat throughout coastal Ecuador.

A study was carried out on breeding Horned (Slavonian) Grebes (Podiceps auritus) in Scotland to investigate causes of low breeding success. Clutch and brood survival were examined separately, as well as overall breeding success. For those clutches where the cause of loss was known, most were lost to avian predators. Clutch survival was negatively correlated with crow (Corvus spp.) frequency and variability in water levels. Brood survival was lower where the introduced fish species, Pike (Esox lucius) was present and higher where the water was clearer. These factors may have affected predation rates and foraging efficiency, respectively. Overall productivity (young fledged per pair) was negatively related to the frequency of crows and number of bank anglers, who can disturb grebes. Remains of 19 fully-grown birds were found at five lakes. Some had been skinned and dismembered in a similar way, suggesting predation by a mustelid. Steps to improve productivity should include education of bank anglers, and perhaps selective removal of Pike and crows. Alternatively, breeding habitat could be improved at lakes where predators are less common.

Since their recovery from population declines in the 1960s and 1970s, Brown Pelicans (Pelecanus occidentalis) have become a common breeder on the Atlantic coast of the southeastern U.S.A. Despite their relative abundance, few studies of their breeding biology have been conducted in this region. Parent and nestling behavior during early chick rearing were examined at a colony in Charleston Harbor, South Carolina. Rates of parental and chick feeding decreased linearly with chick age. Rates of parental attendance, chick begging and chick aggression all peaked when chicks were approximately 21 d post-hatching and then declined. Direct feeding events were never observed when chicks were < 11 d of age and indirect feeding events were rarely observed after chicks were > 15 d of age. The transition from indirect to direct feeding was not accompanied by a change in begging rates. Shifts in the frequencies of both parent and chick behaviors occurred at approximately three weeks post-hatching, when chicks achieve thermoregulatory independence and become more mobile. These data suggest that any spatial or temporal comparisons of parent or chick behavior should be assessed in relation to the age category of the parent and the age of the chicks.

Nest-site selection and nest success for Red-breasted Mergansers (Mergus serrator) breeding on a barrier island complex (Tern Islands) with >10,000 Common Terns (Sterna hirundo) in eastern New Brunswick, Canada, were studied in 2005 and 2006. Concealment was the most important feature for nest placement as 153 of 156 nests were in dense stands of Marram Grass (Ammophila breviligulata), and overhead concealment, vegetation density and vegetation height were all greater at nests than at random locations. Apparent success for all nests was 57% and was similar between years. Few nests were depredated (N = 3), but abandonment was responsible for 95% of nest losses and was most common early in the season. Nest success was <45% for nests initiated before 25 May but >75% for nests initiated after 10 June. Nest abandonment was influenced by intraspecific nest parasitism and investigator activity. Red-breasted Mergansers selected nest sites adaptively on Tern Islands because: 1) nests were more concealed than random sites; 2) avian predation at nests in the Common Tern colony was lower than at nests on nearby islands without terns; 3) nests were not exposed to mammalian predators; and 4) nest success and nest densities were high.

A substantial proportion, perhaps 30%, of the North American breeding population of Long-tailed Ducks (Clangula hyemalis) winter in the vicinity of Nantucket Island, Massachusetts. These birds spend the night on Nantucket Sound and commute during daylight hours to the Nantucket Shoals, which extend about 65 km offshore from the southeastern corner of Nantucket. Strip transects done from a single-engine plane in 1997 and 1998 indicated that Long-tailed Ducks foraged over the shallower (≤ 20 m depth) portions of the Nantucket Shoals, up to 70 km offshore. Diet analyses of ten birds collected in February 1999 and five in December 2006 showed that they fed principally (106.6 /- 42.0 individuals per crop) on Gammarus annulatus, a pelagic amphipod that often forms large aggregations, and is consumed by several species of fish and marine mammals. Our findings emphasize the importance of conservation of the Nantucket Shoals and the prevention of oil spills or other potentially harmful accidents.

Stable isotope analyses have revolutionized the study of migratory connectivity. However, as with all tools, their limitations must be understood in order to derive the maximum benefit of a particular application. The goal of this study was to evaluate the efficacy of stable isotopes of C, N, H, O and S for assigning known-origin feathers to the molting sites of migrant shorebird species wintering and breeding in Argentina. Specific objectives were to: 1) compare the efficacy of the technique for studying shorebird species with different migration patterns, life histories and habitat-use patterns; 2) evaluate the grouping of species with similar migration and habitat use patterns in a single analysis to potentially improve prediction accuracy; and 3) evaluate the potential gains in prediction accuracy that might be achieved from using multiple stable isotopes. The efficacy of stable isotope ratios to determine origin was found to vary with species. While one species (White-rumped Sandpiper, Calidris fuscicollis) had high levels of accuracy assigning samples to known origin (91% of samples correctly assigned), another (Collared Plover, Charadrius collaris) showed low levels of accuracy (52% of samples correctly assigned). Intra-individual variability may account for this difference in efficacy. The prediction model for three species with similar migration and habitat-use patterns performed poorly compared with the model for just one of the species (71% versus 91% of samples correctly assigned). Thus, combining multiple sympatric species may not improve model prediction accuracy. Increasing the number of stable isotopes in the analyses increased the accuracy of assigning shorebirds to their molting origin, but the best combination - involving a subset of all the isotopes analyzed - varied among species.

Mercury exposure may be linked to several sources of variation related to habitat conditions and species ecology. In generalist birds, feeding habits may change quickly in response to environmental conditions, prey availability and individual requirements. Stable nitrogen isotope ratios (δ¹⁵N) were used as a marker of trophic level, and stable carbon isotope ratios (δ¹³C) as a marker of carbon sources (terrestrial vs. marine) in food webs involving waterbirds, to infer the effect on mercury exposure due to differences in feeding ecology and the relative dependence on aquatic environments. Four generalist species occupying three different habitats were examined during the breeding season. Habitats: Brackish water - saltwater (saltpans), brackish water - freshwater (ricefields and some saltpans) and terrestrial environment (steppes). Species: Avocet (Recurvirostra avosetta), Black-winged Stilt (Himantopus himantopus), Kentish Plover (Charadrius alexandrinus) and Cattle Egret (Bulbucus ibis). Chick feathers were collected at several locations between 2000 and 2003. Species used resources differently in the environment, and distinct pathways were involved in the mobilization of mercury into food webs. The positive relationship between feather δ¹⁵N values and mercury levels indicated mercury bioaccumulation and biomagnification. Inter-specific variation in feather δ¹³C values revealed a different relative dependence among species on terrestrial vs. aquatic prey. Intra-specific variation in feather δ¹³C values also indicated differential use of marine inputs within each species, and within saltpans for Avocet chicks. Feather mercury levels and δ¹³C values suggested that the relative use of marine-derived prey influences mercury levels in chicks.

The determination of genetic parameters for most waterbird populations presents considerable challenges because these species frequently breed in inaccessible locations which preclude capture of nesting pairs. The application of non-invasive sampling techniques, such as the collection of molted feathers in the field, could represent an appealing strategy to overcome the above cited problem. Here, the feasibility of sampling molted feathers collected in Brazilian populations of the Roseate Spoonbill (Platalea ajaja; N = 94) and the jabiru Stork (Jabiru mycteria; N = 10) for genetic studies was evaluated. Each feather yielded high quality DNA with a concentration 1.25 times higher than that obtained from feathers from similar sized birds from other groups. Amplification of a 390– 396 bp fragment for molecular sexing and 11 microsatellite loci was successful. The average percentage of positive PCRs (i.e. those that yielded products) among all Roseate Spoonbill loci and samples was 95.5%. The sampling approach appears suitable to gather genetic information in natural populations of these waterbirds and can be applied to other similar species.

Cats (Felis catus) were probably introduced to Reunion Island (Western Indian Ocean) in the seventeenth century and feral populations are now spread over all anthropogenic and native habitats. The diet of feral cats living in the breeding habitat of Barau's Petrel (Pterodroma baraui), an endemic and threatened seabird of Reunion Island, were studied. Results from the analysis of 217 scat (333 prey items) showed that Barau's Petrel were the most common prey of feral cats, followed by introduced rodents. Numerous dead birds at breeding colonies that had been killed by cats were found, 58% of the birds were adults. Given the high sensitivity of the population growth rate of a long-lived seabird to any additive mortality of adults, these results are particularly worrying. As this species is also threatened by massive light-induced mortality of fledglings, it is highly likely that this population is declining. A control of cats at breeding colonies is urgently needed to save this species from extinction.

The Punta de Manabique Wildlife Refuge in the inner Gulf of Honduras, Guatemala, was surveyed for shorebirds from August 2000 to June 2001. Shorebirds were counted along beaches, coastal lagoons and river mouths. A total of 25 species was recorded. Species richness and abundance were highest in a zone where several river mouths and coastal lagoons occurred. The most common species, each accounting for >5% of all individuals observed, were in decreasing order of abundance: Spotted Sandpiper (Actitis macularius), Sanderling (Calidris alba), Black-bellied Plover (Pluvialis squatarola), Collared Plover (Charadrius collaris), Least Sandpiper (Calidris minutilla), Whimbrel (Numenius phaeopus), and Semipalmated Plover (Charadrius semipalmatus). Species composition differed between autumn and spring by 42%. For all surveys a total of 2,673 individuals was recorded, and flock size ranged from 2 to 35 birds, indicating that Punta de Manabique is a secondary migration site for shorebirds.

The status and breeding success of Glossy Ibis (Plegadis falcinellus) in Numidia, Algeria and factors affecting its conservation in Algeria and North Africa were investigated during 2002–2007. After a century and a half of apparent interruption, reproduction was once again noted at Lake Fetzara and three new breeding sites: Dakhla, Chatt and Lake Tonga. At the latter site, colonies shifted location annually between 2002 and 2006 and were often split into subcolonies located on distinct islets. Egg-laying occurred between mid-April and the end of June, beginning over a month earlier in 2004 than in 2005. Mean clutch size for the combined three study years (2004, 2005 and 2007) was 3.7 ± 0.6 (N = 49 clutches). Hatching success amounted to 89% (29 clutches) and an average of 2.7 ± 0.9 chicks per nest survived to twelve days. Habitat loss and degradation as well as lack of management plans are identified as major threats to the future of the Glossy Ibis in Algeria.

Colonization pattern, clutch size variations and nest mortalities were studied in a wild population of Painted Stork (Mycteria leucocephala) in Delhi Zoo, India during 2005–2006. Among the seven different colonies in the zoo, colony 3 was the first to be occupied in both years. Nest initiation dates were significantly different across colonies. Initiation dates of satellite colonies were 7–15 days later than the island colonies (16–19 August). Clutch size varied among different colonies (1.41–3.04) with colonies 3 and 4 exhibiting highest values, 3.04 and 2.70 respectively. Birds nesting early (<14 days since nest initiation date) had higher clutch sizes compared to later nesters and those nesting in satellite colonies. House Crow (Corvus splendens) and Black Kite (Milvus migrans) were the major predator on eggs and chicks. The significance of site specific studies in providing conservation insights and setting the foundation for long term population monitoring projects is highlighted.

Changes in clutch size and fledging success associated with the height and distance from shore of nests were investigated in a colony of Black-crowned Night Heron at Poyrazlar Lake, Turkey. A total of 100 nests in five plots were surveyed in 2007. Nest height varied between 45–300 cm, with a tendency to be lower further from shore. Clutch size appeared independent of nest location and variable, with 37% of nests with two eggs, 32% with three eggs, 22% with four eggs and 9% with five eggs. Fledging success was approximately 67% for plot 1, nearest to shore, but increased up to 94% for plot 5, furthest from shore.