Disease, Climate Change, and Predators Threaten Breeding Populations of American White Pelicans

Marsha Sovada PhD

Wildlife Research Biologist,

Northern Prairie Wildlife Research Center,

US Geological Survey, Jamestown, North Dakota

 3:00 pm Wednesday, March 18, 2009

404A Shepherd Union Building

 

For information contact - John Cavitt or Amy Douangdara (801.626.8541)

American White Pelicans nest colonially at only a few sites throughout North America, making the species particularly vulnerable to disease, disturbance, predation and weather events.  Nearly half of the population breeds at four colonies in the northern plains; thus, sustained productivity at these colonies is crucial.  Beginning in 2002, unusually high mortality of pelican chicks was noted at the four northern plains colonies. During 2004-2008, we monitored three of these four colonies to assess mortality of chicks. Weather events and West Nile virus (WNv) were documented as major causes of mortality. Weather-related mortality might be a more important factor now than in the past because pelicans are arriving at breeding sites almost 2 weeks earlier than 40 years ago.  In addition, complete abandonment of a colony in 2004 which contained approximately 7000 nests was attributed to coyotes.  Persistent low productivity at white pelican colonies in the northern plains likely is reducing the adult breeding population in the region.

Sovada et al. 2008. Biological Conservation 141:1021-1031.

For information contact - John Cavitt or Amy Douangdara (801.626.8541)