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Methylmercury biomagnifies in food chains and can lower reproductive success in many organisms, particularly in top predators such as Brown Pelicans (Pelecanus occidentalis). To determine and compare variability in mercury exposure in this species, chick feathers and egg membranes were collected from seven breeding sites located in the remote Pamlico Sound and the more human-impacted Cape Fear River in North Carolina, USA. The average concentration of total mercury in egg membrane was 0.20 ± 0.14 ppm dry weight, a level associated with slightly reduced reproductive success in some birds, while chick feather total mercury concentrations (1.13 ± 0.02 ppm fresh weight) were well below the lowest observable adverse effects level. Mercury exposure did not vary between the Cape Fear River and Pamlico Sound, but did vary significantly among three Cape Fear River colonies. Diet analysis using δ13C and δ15N revealed minimal differences in the trophic level and foraging location of prey between islands in close proximity, indicating that differences in mercury availability are not due to differences in diet composition. The source of mercury variation in Brown Pelicans remains unknown and in need of further study.

Nest and chick census data gathered from 1975–2005 at all known breeding colonies of Royal (Sterna maxima) and Sandwich (S. sandivicensis) Terns in three mid-Atlantic States are reported. Nest census data were gathered sporadically in North Carolina, Virginia, and Maryland throughout this period. Royal Tern chick counts based on annual banding efforts were obtained in Maryland since 1975 and North Carolina and Virginia since 1977, while Sandwich Tern chick counts date from 1977 in North Carolina and 1980 in Virginia. Royal Tern chick counts show significant annual variation by state, and are positively correlated between North Carolina and Virginia, but negatively correlated between Maryland and both North Carolina and Virginia. Sandwich Tern nest counts showed significant annual variation in North Carolina, as did chick counts in North Carolina and Virginia. These results suggest regional, rather than local, trends in Royal Tern numbers over time. While Royal Tern numbers indicate a gradual dec...

Royal Tern (Sterna maxima) chick diet at Fisherman Island National Wildlife Refuge, Virginia, was investigated in 2003 and 2004. Primary objectives were to document common prey species, annual and seasonal variation in prey selection, and seasonal variation in prey size based on average bill length in this species. Over 2200 Royal Terns bred on this island each year of the study. Single items of prey species carried in the bill by adult terns feeding their chicks were identified using 8 × 42 binoculars. A total of 11,566 and 33,646 prey items were identified during 44 and 87.5 h of systematic observations in 2003 and 2004, respectively. Terns foraged largely on anchovy (Anchoa spp.) early in the season, then switched to herrings (Clupeidae); average prey size also increased seasonally each year. Prey switching was similar to that of Royal Terns in North Carolina (but with drum as well as herring), indicating regional adaptations to forage fish availability by this species along the mid-Atlantic s...