Brandt's Cormorant (Phalacrocorax penicillatus) breeding effort, phenology and success were studied in 1997-2001 at three colonies spanning approximately 200 km of the central California coast: Point Reyes (PR); Devil's Slide Rock and Mainland (DS); and Castle-Hurricane Colony Complex (CH). Breeding effort was reduced at all three colonies in the 1998 El Niño event. Mean clutch initiation dates differed significantly among colonies, with cormorants at the southernmost colony (CH) laying earliest, and those at the northernmost colony (PR) laying latest. Productivity at individual colonies varied greatly among years (range 0.7-2.5 fledglings per pair). Overall colony means were lowest (1.6 fledglings/pair) during the 1998 El Niño event and highest (2.5 fledglings/pair) in the 1999 La Niña event. Productivity at CH (1.7 fledglings/pair) was significantly lower than at PR (2.2 fledglings/pair), and interannual variation was greatest at CH. Late-nesting birds laid fewer eggs, hatched fewer chicks, and fledged fewer chicks per pair than early-nesters. The rapid rate of growth at some nearshore colonies in central California suggests immigration from elsewhere, most likely the large offshore colony at the South Farallon Islands. Variation in timing of breeding and reproductive success among colonies demonstrates a value in maintaining multiple study locations when assessing Brandt's Cormorant population parameters in the California Current System.

This study quantifies the relative importance of factors affecting selection of brood-rearing areas by Common Eiders (Somateria mollissima) according to duckling age. A total of 1,431 h of observation was conducted from June-August on the New Brunswick mainland in 2000 and on Grand Manan Island in 2001. The number of breeding pairs of Great Black-backed Gulls (Larus marinus) on colonies near study sites appeared to be a better predictor of duckling abundance in sites than the number of Common Eider nests on those colonies. Neither degree of exposure of site nor availability of rockweed (Ascophyllum nodosum) explained variations in duckling abundance. However, sites with a gradual slope, which offer increased surface-feeding area, supported 43-85% more ducklings than sites with a steep slope. Rockweed-harvested sites with a steep slope supported the least number of ducklings on Grand Manan Island, and duckling numbers on the mainland decreased faster in harvested than in control sites. Predation was unimportant, with only nine successful predator attacks on ducklings occurring. Of those, Bald Eagles (Haliaeetus leucocephalus) were responsible for six duckling losses. However, Common Eiders may have avoided Herring Gulls (L. argentatus) in duckling-feeding sites, possibly to avoid klepto-parasitism on eiders by gulls. Human disturbance was also a minor factor.

King Rail (Rallus elegans) populations are listed as threatened or endangered in 13 states. One remaining area of relative abundance is the rice-growing region of southwestern Louisiana. Rice fields are flooded for much of the year and support thick emergent vegetation, potentially providing high-quality habitat for King Rails. The objectives of this study were to determine: 1) relative nest density of King Rails in rice; 2) which local and landscape factors influence relative nest densities; 3) nest survival of King Rails in rice fields; 4) effectiveness of callback surveys in indicating King Rail breeding activity; and 5) site occupancy of King Rails in rice fields. In the summers of 2004 and 2005, King Rail surveys and nest searches were conducted in Cameron, Jefferson Davis, Vermilion, and Acadia Parishes in southwestern Louisiana. In 2004, 42 fields were searched for nests and 30 of those were surveyed with callback survey techniques. In 2005, 40 fields were searched and 60 were surveyed. A total of 77 King Rail nests was found, and relative nest density was between 3.4 and 4.8 nests/km². The highest nest densities were in fields with a high proportion of irrigation canals around the perimeters and a low proportion of trees. Nest survival was ∼50% in both years. Most survey responses were detected in June, and survey detections were correlated with nest abundance. Site occupancy was estimated as 0.35 ± 0.11 in 2004 (no estimates for 2005) from callback surveys and between 0.4 (2004) and 0.5 (2005) from nest searches. Callback surveys were an effective technique for monitoring King Rails in this region. Given high nest survival rates and apparently stable nest densities, rice fields appear to provide high-quality habitat for King Rails in southwestern Louisiana.

Flight patterns of Great Egrets (Ardea alba) and Snowy Egrets (Egretta thula) arriving at and departing two mixed-species colonies were studied in Wichita, Kansas, in May and June 2007. For 137 short-distance flights (about 200 m) at one colony, flight duration and flight distance were recorded and wing beats were counted. For 90 longer flights (about 1,200 m) at a second colony, flight durations were recorded. From these data, wing-beat frequencies and flight velocities were calculated, then wind vector addition was used to determine air speeds and examine the effects of wind velocity and wind direction on flight patterns. Using published algorithms and data from two of our previous flight line studies, the daily energetic costs of foraging flights were estimated. Flight patterns by Great Egrets and Snowy Egrets showed some similarities. For example, mean air speeds for Great Egrets (9.2 m/s) did not differ from those of Snowy Egrets (8.7 m/s). Differences between species included lower wing-beat frequencies by Great Egrets and a much stronger effect of headwinds on Snowy Egret flight velocities. Energetic requirements for flight also differed between species, which are ascribed to differences in wing-loading and mass. The cost of an average flight for each species was estimated, and daily flight costs were compared to overall daily energy budgets. Flight comprised 25.9% of the total energy budget for Great Egrets and 27.5% for Snowy Egrets. Based on previous foraging studies, a Great Egret can meet its daily energy requirements for flight after an estimated 82 min of foraging, whereas a Snowy Egret must forage for 168 min to capture enough prey to meet the daily demands for flight. This study represents the next stage in our development of annual time-and-activity budgets for these two species of wading birds.

The Peruvian Tern (Sternula lorata) is one of the rarest seabirds that breed on the barren desert plains of Peru and Chile. Unlike the majority of seabirds breeding in this region, Peruvian Terns nest in open areas on the mainland, where they are exposed to attacks by predators, mainly foxes (Pseudalopex spp.). Here, we describe the Peruvian Tern's breeding biology and examine its ecological adaptations to counteract high predation rates from data collected during the 1970s and 1990s at four localities in central-southern Peru: Puerto Viejo (12°34'S), Pampa Lechuzas (13°53'S), Yanyarina (15°26'S) and Mollendo (17°04'S). Egg-laying was asynchronous both within and among breeding groups, spreading from mid October to late January. Modal clutch size was two eggs, which were incubated for 22 d. Weight increment for two chicks during the linear section of the growth curve was 2.27 and 2.54 g/d. A complete body weight growth curve for one chick was fitted to the logistic equation with K_L = 0.193 d^-1, A = 50.66 g and t_i = 9.9 d. The proportion of nests that hatched at least one chick at Puerto Viejo varied from complete failure in 1971-72 to 80% (N = 6 nests) in 1973-74. Birds did not attempt to breed during El Niño 1972-73. Low nest density (five to seven nests/km²), absence of nest material, camouflage of eggs and chicks, and high mobility of chicks few days after hatching are traits that may decrease nest detection by predators. Conversely, presence of landmarks such as clusters of stones, shell chips, tire tracks and broken glass close to the nest probably enhance nest location by parents in the featureless environment of the desert. Prey remains found in the nests were seven to eight cm Peruvian Silversides (Odonthestes regia regia) and Mote Sculpins (Normanichthys crockeri). The breeding biology and nesting strategies of Peruvian Terns are very similar to the closely-related Damara Tern (Sternula balaenarum) from the coast of South-western Africa and may have evolved to reduce high rates of mammalian predation.

In South America, Royal Terns (Thalasseus maximus maximus) and Cayenne Terns (Thalasseus sandvicensis eurygnathus) breed mostly in Argentina and Brazil. Royal Terns have been recorded in at least 22 locations (six in Brazil and 14 in Argentina). Cayenne Terns have been recorded in at least 38 locations (15 in Brazil and 23 in Argentina). At 15 locations, mostly located in Argentina, Royal and Cayenne terns breed in association, often with their nests intermingled. Total population size for Royal Terns was estimated in at least 750 pairs in Brazil and less than 5000 in Argentina, while that of Cayenne Tern was estimated in at least 8000 pairs in Brazil and less than 10000 in Argentina. However, lack of counts at some coastal sectors and changes among breeding sites between seasons preclude an accurate estimation of total population size for both species and make spatial management challenging. Main threats faced by their populations in both countries are human disturbance, fisheries, egging, and expanding Kelp Gull (Larus dominicanus) populations. Priority research and conservation actions are presented.

Fledgling counts are often used to estimate fledgling production or calculate an index of chick survival (i.e., fledging success) in the Least Tern (Sterna antillarum). Timing of counts is critical because numbers of fledglings present may be influenced by temporal patterns in fledgling departures from colonies and post-fledging mortality. The objectives of the present study were to measure chick survival and fledgling residence time (FRT) at three Least Tern colonies in Maine and examine the accuracy of single or multiple counts of fledglings for estimating fledgling production and fledging success. Chicks were color-banded at age zero to one d in 2002-2003 to estimate chick survival using mark-resighting methods and to examine relationships between fledging date and FRT. Colony sites were searched for banded chicks and fledglings every one to three d from just prior to fledging until their disappearance from the vicinity of nesting areas at three colonies. Data on numbers of banded fledglings known alive on each survey date were used to simulate single or periodic counts of banded fledglings for the purpose of comparing estimates of fledgling production and success based on count methods with known values. Chick survival estimates were 0.73, 0.74, and 0.14 for the three colonies. Fledgling residence times decreased relative to fledging date at all colonies, and the trend for maximum values of FRT, which may be an indicator of the maximum time to departure, varied from approximately 30 d in mid-July to 15 d in early to mid-August. The highest one-d counts of fledglings underestimated fledgling production by 21-30% for the two sites with high chick survival. Methods based on multiple counts also tended to underestimate fledgling production. Fledgling residency patterns limit the utility of count methods for estimating fledgling production and fledging success.

Feeding activity of wintering Common Eiders (Somateria mollissima) was conducted in Southwest Greenland. Behavioral observations were made at two wintering sites, a fjord habitat and an outer coastal habitat, at which habitat characteristics and human activities differed considerably. In the coastal area where hunting and fishing was common and foraging typically occurred 0.5 to one km from the shore eiders were identified as primarily diurnal feeders. They also foraged during twilight periods, but only rarely at night. In contrast, in the fjord where human disturbance was rare and foraging occurred very close to the shore (<50 m) adult eiders fed only during twilight and at night. During daytime, birds gathered in large communal roosts in open water away from feeding areas. Occasionally, feeding was initiated by juveniles during daytime, but was discontinued due to interactions with White-tailed Eagles (Haliaeetus albicilla groenlandicus) and suggests that nocturnal feeding is an anti-predator mechanism. More experienced adult birds in the fjord did not attempt feeding during daylight hours. Large communal roosts observed at deep waters during previous aerial surveys suggest that nocturnal feeding maybe common throughout the fjords in Southwest Greenland.

Selection of a foraging site entails costs and benefits which are reflected in survival and reproductive success. We studied Piping Plover (Charadrius melodus) foraging-site selection during the breeding season (2001-2003) on the Missouri River and examined the relationship between site selection and invertebrate abundance indices within habitats. Foraging adult plovers selected protected shoreline (inter-sandbar channels, inlets, and backwater areas) more often than expected based on availability (use: 92% ± 3%; availability: 58% ± 5%). Invertebrate biomass and numbers along exposed shoreline did not differ among reaches. Along the protected shoreline, invertebrate biomass and numbers were higher below a dam with an epilimnetic release and a relatively constant release rate (epilimnetic reach) than at the other two reaches. On the epilimnetic river reach, invertebrate biomass and numbers were higher along the protected shoreline than on the main channel shoreline. On a reach below a dam with a hypolimnetic release and diel flow pulse (hypolimnetic reach) and a cold water reservoir, invertebrate indices were similar on the protected and exposed shoreline. Invertebrate numbers were higher in saturated and moist habitats than in vegetated and dry habitats (P < 0.05). At the epilimnetic and hypolimnetic reaches, foraging Piping Plover chicks used saturated and moist habitats more than vegetated and dry habitats, based on availability. On the Missouri River, protected shorelines were important foraging sites for Piping Plovers during the breeding season, and sandbars with low-lying moist habitat were important to foraging chicks. Piping Plovers will benefit from increased availability of these habitats on managed or created sandbars on the Missouri River.

Populations of egrets and other waterbirds in the Murray-Darling Basin of eastern Australia are declining. River regulation and increasing frequency of droughts are considered to be mainly responsible by reducing the frequency and extent of flooding to temporary wetlands. However, other changes have occurred to wetlands, such as the introduction of non-native fish, widespread severe declines in the abundance of native fish, increased salinity, sediment and nutrient concentrations, and removal of aquatic vegetation by livestock grazing. Current knowledge of the diets of egrets is inadequate for an assessment of any ecological implications arising from these changes. In this study the breeding season diets of Eastern Great Egret Ardea modesta and Intermediate Egret A. intermedia were quantified at a colony in the Murray Basin. Eastern Great Egrets depended mainly on introduced Common Carp Cyprinus carpio (94% of diet biomass), a species regarded as a severe pest of river systems and wetlands within the Basin. Attempts to eliminate carp, without adequate restoration of native fish populations, could result in further long-term declines in egret breeding success and survival. Intermediate egrets depended mainly on adult and larval frogs (80% of diet biomass), species that are under threat from habitat degradation and predicted increases in the salinity of freshwater wetlands. A holistic approach to the restoration of wetlands, involving the integration of improved flooding regimes, pest fish management and reinstatement of native fish and amphibians, salinity control and restoration of aquatic vegetation will be needed to ensure the future of egrets and other fish-eating birds in the Murray-Darling Basin.

The emergence of highly pathogenic avian influenza (HPAI) H5N1 has elevated concerns about wild birds as virus hosts; however, little is known about the ecological and epidemiological factors of transmission by shorebirds. Here we summarize results for 2,773 shorebirds that were live-trapped on the Pacific coast of the United States during 2006-2007 and tested for avian influenza virus using real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and virus isolation. As was the case throughout North America, HPAI H5N1 was not detected in shorebirds during this interval. Contrary to other wild bird groups, most notably waterfowl, the prevalence of even low pathogenicity virus among shorebirds in our study areas in California, Washington, and Alaska was extremely low (0.5%). Virus was detected by RT-PCR from four different species, including, Dunlin (Calidris alpina; N = 3), Western Sandpiper (C. mauri; N = 8), Long-billed Dowitcher (Limnodromus scolopaceus; N = 1), and American Avocet (Recurvirostra americana; N = 1), with the detections in the latter three constituting the first published records for these birds. Based on studies in the eastern United States, we expected, but did not detect (H₁ = 1.6, P = 0.21) elevated avian influenza prevalence among shorebirds during spring migration. Diagnostic tests, which were designed to evaluate testing and sampling methods, indicated poor functioning of traditional virus isolation methods and no improvement in detection likelihood by collecting oropharyngeal swabs in addition to cloacal swab samples for low pathogenicity viruses (Z₁ = 0.7, P = 0.48).

Prey consumed by breeding Pacific Gulls (Larus pacificus) were identified and quantified on seven islands in the Furneaux Group, Bass Strait, Australia, over the 2003/04 austral summer to examine temporal and spatial variation in dietary preference. Non-invasive dietary sampling involved collection of non-consumed parts of prey (large particles) and regurgitated pellets of prey remains (pellets) from feeding platforms every two weeks. Of the128 prey items identified, 17 of these items were prominent in the diet of Pacific Gulls. Of these, seven were identified by both large particles and pellets of prey remains, three only as large particles and the remaining seven only in pellets. PRIMER multidimensional scaling revealed differences between stages of breeding and between sites in the abundance of each type of prey found as large particles, but only between sites for prey found in pellets. Based on the relationship between body mass and dietary requirements a breeding adult Pacific Gull requires, on average, 600 kJ/d over the breeding season. This study identified prey corresponding to only 193 ± 35 kJ/d which equates to a total biomass of approximately 1,000 kg of prey being consumed by the 108 breeding Pacific Gulls, or 19 kg per breeding pair. Results were biased toward hard-bodied prey, and hence, this research failed to identify 90% of the food consumed by the Pacific Gull population. Caution is advised against one-off sampling in time and space, and using simple techniques, to examine dietary preference in gulls.

Unlike conspecifics in the subantarctic region, which typically begin breeding in mid-spring to summer, Common Diving-petrels Pelecanoides urinatrix urinatrix in southeastern Australia (towards the northern limit of the species' distribution) commence breeding mid winter. Knowledge of the foraging ecology of this species is crucial to understanding the factors that influence its timing of breeding in the region, yet there is currently little information available. Analysis of 43 stomachs of breeding adults, collected opportunistically after they were killed in a fire which burned through their colony, indicated that their diet was dominated by two taxa: a euphausiid Nyctiphanes australis which comprised 87% of the diet by number; and a hyperiid amphipod Themisto australis which constituted a further 12.5%. Mean lengths (±SE) of N. australis (n = 39) and T. australis (n = 41) were 12 mm (±0.3) and 5.2 mm (±0.2), respectively. The importance of N. australis in the diet of Common Diving-petrels is discussed in relation to their timing of breeding and the euphausiid's potential role in the Bass Strait pelagic ecosystem.

Data on population size and some aspects of the breeding biology of Gentoo Penguins (Pygocelis papua) have been studied as part of a long-term monitoring program at Martillo Island in the Beagle Channel, Tierra del Fuego. The colony of Gentoo Penguin on Martillo Island is the only one reported in Argentina and has been monitored regularly since 2000. Timing and hatching success were similar to those reported at other colonies in the South Atlantic Ocean/Antarctic Peninsula region. A maximum of twelve nests were recorded during the 2006/2007 season, with an average breeding success of 1.0 chicks/nest. The Gentoo Penguin colony at Martillo Island increased by 19% in the past 13 y, while other colonies in the south Atlantic region and the Antarctic Peninsula have been decreasing or stable.

We provide first evidence of cannibalism in fledglings of the Australian White Ibis (Threskiornis molucca) and Australian Pelican (Pelecanus conspicillatus). The ibis only fed on carcasses of dead conspecifics (indirect cannibalism); the pelican consumed live pelican (heterocannibalism) and ibis nestlings.

Many Neartic shorebirds migrate to South America for the non-breeding season, and use several key stopover and wintering sites along the Atlantic coast. However, there is little information about annual shorebird use along the northeast coast of Brazil. This year-long study examined the seasonal occurrence and abundance of shorebirds at Atalaia Nova beach in Sergipe State, Brazil. Of the 13 species recorded, the most abundant were Semipalmated Plovers (Charadrius semipalmatus), Semipalmated Sandpipers (Calidris pusilla), and Sanderlings (Calidris alba). Highest numbers occurred between September and March, and the lowest numbers occurred between April and August. Some species were present throughout the year. Atalaia Nova beach is an important migration stopover and wintering site for shorebirds in northeastern Brazil.

East China is a very important wintering region for many migratory waterbirds, but many species have suffered large population declines over recent decades. However, the limited information available on the current and historical abundances of waterbirds in the region seriously limits our ability to assess the magnitude of these declines. The first comprehensive count of the complete Fujian coastline, conducted over a three-week period in February 2006, provided the opportunity to compare data from this count with historical information on waterbird abundances along the Fujian coast obtained during the second half of the 1800s and early-1990s. Our count total of nearly 110,000 birds of 65 species shows that the Fujian coast is still very important for waterbirds during the wintering period. We obtained abundance comparisons for 28 species of which 19 had declined greatly in the last 100-150 years; four of these are globally threatened. The Anatidae group, in particular, has suffered seriously in diversity and numbers during the last century and this finding is consistent with observed decreases in breeding numbers. Given population declines and the great importance of east China as a wintering area for waterbirds (including some globally threatened species), an important priority should be to determine the current status of the different species throughout the region. This information will be useful in proposing effective conservation measures including monitoring in east China.

Risk factors for predation attempts by Peregrine Falcons (Falco peregrinus) were examined in Semipalmated Sandpipers (Calidris pusilla) during fall staging in the Bay of Fundy, Canada. Odds of attacks may be expected to vary with a host of factors such as time of day, time of year, spacing within groups and weather conditions. During the ebbing tide, 65 surprise attacks by falcons were recorded over 596 observation periods. Two factors emerged as risk factors for predation attempts by Peregrine Falcons on Semipalmated Sandpiper flocks during four consecutive fall staging periods. Falcons initiated attacks more often on denser flocks and later during the migratory stopover. Year, time of day and weather factors did not influence attack rate. These findings may reflect lower anti-predator vigilance in denser groups and the greater numbers of sandpipers available in the later stages of stopover. Fitness consequences of these attacks remain to be established.

Twelve colonies where the Red-legged Cormorant (Phalacrocorax gaimardi) breeds in Argentina were visited. Physical and biological characteristics were recorded at 29 nesting cliffs and at different sectors within cliffs. Forty-five percent of the cliffs were located on continental shores, the rest were on islands. Cliff height and length varied (mean height = 14 ± 5 m, length range = 12 to 3,000 m) but their slope was commonly 80 to 90°. Most cliffs had more than 50% of the total available area with apparent suitable breeding sites. Cliff length and available area was positively correlated with the number of nests. Forty-nine different sectors used by Red-legged Cormorant on the cliffs were identified. In those sectors, number of active nests was positively correlated and nest density negatively correlated with area. Highest median density of nests was NE in orientation, protected from predominant winds. Minimum average distance from the tide line to the closest nest group was positively correlated with both wave effect exposure (fetch in front of the sector) and cliff slope. Probability of occurrence of active Red-legged Cormorant nests in a sector increased with cliff slope. Forty-one percent of cliffs also had nests of the Rock Shag (Phalacrocorax magellanicus). For Red-legged Cormorant, cliff slope, orientation, available area and exposure to waves seemed important for nesting.

Various types of copulatory behavior of individually marked and molecularly sexed Dovekies (Alle alle) were studied in the breeding colony in Hornsund (South Spitsbergen) in 2005-2006. Female-male (reverse) mounting (females mounting males) was recorded in 5% of all 851 observed copulations and copulation attempts. All reverse mountings were observed in one pair of 37 studied during the prelaying period. Female-male mountings made up half of all recorded copulations and copulation attempts in this particular pair. We discuss possible function of female-male mountings. We also describe homosexual male-male, mountings and redirected mountings which made up 0.3% and 1.5% respectively of all observed types of copulatory behavior.

Kleptoparasitism is a common behavior in birds, and seems to be widespread among Ciconiiforms, both intra and interspecifically. Between 20 - 23July 2005, two observations were made of a Great Kiskadee (Pitangus sulphuratus) stealing prey from a Little Blue Heron (Egretta caerulea) in a feeding aggregation on a mudflat in Cananéia, southwestern Brazil. On the two occasions, a Great Kiskadee left a perch to take decapod prey from the heron's bill during a brief hover.