Population Dynamics of Waterfowl Wintering in the Mid-Atlantic Region, USA

• Main Authors: Harris, Abigail, Hoke, Thomas
• Format: Text
• Language: unknown
• Published: Digital Commons @ Longwood University 2020
• Subjects: Environmental Sciences; Biology; Canada; Canada Goose
• Online Access: https://digitalcommons.longwood.edu/rci_fall/42; https://digitalcommons.longwood.edu/cgi/viewcontent.cgi?article=1041&context=rci_fall

A recent study (Rosenberg et al. 2019) has shown that bird populations in North America are experiencing major declines except for a few groups including waterfowl. However, this study focused only on the summer breeding populations and did not focus on regional dynamics. We utilized data from 62 Christmas Bird Count (CBC) count circles to evaluate population dynamics of common wintering waterfowl in the coastal Mid-Atlantic region (Delaware=7, Maryland=16, Virginia=18, North Carolina=21) since 1950. We found a 36% decline of wintering waterfowl relative abundance compared to 1950s. American wigeon and Canada goose had major population decreases while Snow goose had a major population increase. Species wintering in marsh habitats decreased while cavity nesters had an increase. Additionally, omnivore and granivore species had significant declines with no apparent effects on other feeding guilds. Our work suggests significant population declines of many wintering waterfowl species in the Mid-Atlantic region (N = 11; 38% of species studied) despite the continental-scale recovery of waterfowl.