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The Mountain-Prairie Region


U.S. Fish and Wildlife Service
134 Union Boulevard
Lakewood, Colorado 80228


Chase Lake National Wildlife Refuge

March 31, 2005
Contact: Ken Torkelson, (701) 355-8528


The U.S. Fish and Wildlife Service and its partners are preparing for the return of up to 30,000 American white pelicans to Chase Lake National Wildlife Refuge, near Medina, N.D. 

The Refuge is home to North America’s largest nesting colony of white pelicans. Last spring, the large white birds suddenly and for no immediately apparent reason abandoned their nests, eggs and newly- hatched chicks.  Satellite tracking of four adult pelicans from Chase Lake indicated one bird moved to western South Dakota, another went to eastern South Dakota, a third to northern Minnesota, and the fourth to north-central North Dakota. 

Plans are in place at Chase Lake NWR to monitor and protect the pelicans during the 2005 breeding season.  In order to reduce the risk of disturbance to the pelican colony during nesting, the Service will restrict visitor access to the nesting areas.  The entire refuge is normally closed to visitors, and an access permit from the refuge is required.   

In addition, the Service will construct a barrier fence to exclude mammalian predators, such as coyotes and foxes, from the peninsula colony where abandonment was first observed last year. 

Scientists from the U.S. Geological Survey’s Northern Prairie Wildlife Research Center will be at Chase Lake to conduct a companion study to a West Nile virus assessment that began in 2004.  To minimize human disturbance, researchers will use surveillance cameras, binoculars and spotting scopes to observe the colony from a distance.  After pelican eggs have hatched, biologists will place satellite transmitters on ten adult pelicans.  These transmitters will provide data for the next three years to help determine nest attendance, proportion of time spent away from the colony, distances traveled to foraging sites, and locations and characteristics of the foraging sites.  Similar observations will be made at pelican colonies in northeastern South Dakota and northwestern Montana

Other partners in the 2005 protection and monitoring efforts at Chase Lake include the ND Game and Fish Department, USDA Animal and Plant Health Inspection Service, and the ND Chapter of The Wildlife Society.  

During an 8-day period in late May and early June 2004, biologists observed a rapid decline in the pelican population at Chase Lake, from an estimated 27,000 birds to total abandonment at two of the three nesting sites on the refuge.  Adult pelicans left behind thousands of unhatched eggs.  The third nesting site, located on a large island, contained about 2,500 nests, and nesting activity there appeared to be progressing normally.  However, a check of this island in late June revealed that those nests, most with hatched young, had also been abandoned.  None of the chicks survived. 

The cause or causes of this mass abandonment have not been determined.  Some possibilities include disturbance by predators, human disturbance, severe weather, food shortages, and disease.  However, investigations into each of these possibilities have resulted in few if any answers. 

The Service and its partners may never completely understand the causes of the 2004 abandonment of the Chase Lake pelican colony.  However, all of the agencies and organizations studying the pelicans at Chase Lake believe data from the observers, cameras, transmitters and the West Nile virus evaluation will contribute valuable information about pelican biology and provide a basis for effective management and conservation of American white pelicans. 

Chase Lake NWR was established by President Teddy Roosevelt in 1908 as the 15th refuge in a system that has since grown to 545 units.  A large portion of the refuge was designated as a Wilderness Area in 1975.  The refuge and surrounding prairie grasslands and wetlands support a rich diversity and abundance of migratory waterfowl, shorebirds, colonial water birds, raptors and other wildlife.  Chase Lake NWR is internationally recognized for hosting the largest breeding colony of American white pelicans in North America. 

The U.S. Fish and Wildlife Service is the principal Federal agency responsible for conserving, protecting and enhancing fish, wildlife and plants and their habitats for the continuing benefit of the American people. The Service manages the 95-million- acre National Wildlife Refuge System, which encompasses national wildlife refuges, as well as thousands of small wetlands and other special management areas. It also operates 69 national fish hatcheries, 64 fishery resources offices, and 81 ecological services field stations. The agency enforces Federal wildlife laws, administers the Endangered Species Act, manages migratory bird populations, restores nationally significant fisheries, conserves and restores wildlife habitat such as wetlands, and helps foreign and Native American Tribal governments with their conservation efforts. It also oversees the Federal Assistance program, which distributes hundreds of millions of dollars in excise taxes on fishing and hunting equipment to State fish and wildlife agencies. 

 - FWS - 

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