North American Brant: effects of changes in habitat and climate on population dynamics

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2005
• Subjects: brant; Branta bernicla hrota; Branta bernicla nigricans; breeding; climate change; migration; molting; North America; winter; Arctic; Brant; Pacific; Branta bernicla; Climate change
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.465.5488; http://www.humboldt.edu/wildlife/faculty/black/pdf/Ward et al. 2005 GlobChBio.pdf

We describe the importance of key habitats used by four nesting populations of nearctic brant (Branta bernicla) and discuss the potential relationship between changes in these habitats and population dynamics of brant. Nearctic brant, in contrast to most geese, rely on marine habitats and native intertidal plants during the non-breeding season, parti-cularly the seagrass, Zostera, and the macroalgae, Ulva. Atlantic and Eastern High Arctic brant have experienced the greatest degradation of their winter habitats (northeastern United States and Ireland, respectively) and have also shown the most plasticity in feeding behavior. Black and Western High Arctic brant of the Pacific Flyway are the most dependent on Zostera, and are undergoing a shift in winter distribution that is likely related to climate change and its associated effects on Zostera dynamics. Variation in breeding propensity of Black Brant associated with winter location and climate strongly suggests that food abundance on the wintering grounds directly affects reproductive performance in these geese. In summer, salt marshes, especially those containing Carex and Puccinellia, are key habitats for raising young, while lake shorelines with fine