Historical and Current Population Trends of Herring Gulls (\u3ci\u3eLarus argentatus\u3c/i\u3e) and Great Black-backed Gulls (\u3ci\u3eLarus marinus\u3c/i\u3e) in the New York Bight, USA

During the 20th century, gull populations in North America experienced considerable changes in abundance and geographic ranges. The objective of this study was to describe population trends of Herring Gulls (Larus argentatus) and Great Black-backed Gulls (L. marinus) in the New York Bight, USA, over a 40-year period (1974-2013). A variety of data sources using different survey methods provided estimates of the number of breeding pairs for both species. In the Long Island portion of the New York Bight, overall Herring and Great Black-backed gull nesting populations appear to have fluctuated considerably in size during this time period, and the largest numbers of breeding individuals of these two species occurred in the 1980s. In coastal New Jersey, the Herring Gull nesting population has remained relatively constant, whereas the Great Black-backed Gull nesting population has increased. Individual nesting colonies are dynamic and can vary in size considerably during even short time periods. Several factors, including sea-level changes and the availability of anthropogenic food sources (i.e., at landfills and fisheries by-catch), likely have strongly influenced individual colonies and the overall Herring and Great Blackbacked gull breeding populations in the New York Bight

Project Safe Flight: Making New York Safe for Migratory Birds

More than 100 species of migratory birds pass through New York City during spring and fall migrations. Located at the nexus of several migratory routes, New York City’s tall buildings and reflective glass pose a serious threat to over 100 species of migratory birds. Since 1997, NYC Audubon has led Project Safe Flight (PSF), a volunteer-based citizen-science project, with the goal of monitoring and mitigating bird collisions. We examined 16 years of PSF data, during which volunteers collected over 6,000 birds of 126 different species. The top two species, White-throated Sparrow and Common Yellowthroat, make up 23% of all collisions. The fall migration has a higher average number of collisions than spring. Distinct phenological trends in species composition are apparent, with American Woodcock making up the majority of early spring collisions and Dark-eyed Junco being the most common in late fall. Because birds may be overlooked by volunteers or be taken by scavengers or maintenance crews after collisions, we performed a persistence study and found that the recovery of bird carcasses was highly variable between sites. This ongoing study is important in developing a database of bird collisions to help elucidate and reduce the causes of urban bird collisions

Historical and Current Population Trends of Herring Gulls (\u3ci\u3eLarus argentatus\u3c/i\u3e) and Great Black-backed Gulls (\u3ci\u3eLarus marinus\u3c/i\u3e) in the New York Bight, USA

During the 20th century, gull populations in North America experienced considerable changes in abundance and geographic ranges. The objective of this study was to describe population trends of Herring Gulls (Larus argentatus) and Great Black-backed Gulls (L. marinus) in the New York Bight, USA, over a 40-year period (1974-2013). A variety of data sources using different survey methods provided estimates of the number of breeding pairs for both species. In the Long Island portion of the New York Bight, overall Herring and Great Black-backed gull nesting populations appear to have fluctuated considerably in size during this time period, and the largest numbers of breeding individuals of these two species occurred in the 1980s. In coastal New Jersey, the Herring Gull nesting population has remained relatively constant, whereas the Great Black-backed Gull nesting population has increased. Individual nesting colonies are dynamic and can vary in size considerably during even short time periods. Several factors, including sea-level changes and the availability of anthropogenic food sources (i.e., at landfills and fisheries by-catch), likely have strongly influenced individual colonies and the overall Herring and Great Blackbacked gull breeding populations in the New York Bight