(e) = estimate; * = morbidity and mortality

Southeastern Cooperative Wildlife Disease Study (SC); California Department of Fish and Game - Wildlife Investigations Laboratory (CA); National Wildlife Health Center (NW); Colorado State University Veterinary Diagnostic Laboratory (CO); Illinois Department of Conservation (IL); Kentucky Department of Fish and Wildlife Resources (KY); Murray State University Breathitt Veterinary Center (MS); New York State Department of Environmental Conservation (NY).

Written and compiled by Gregory Kidd, National Wildlife Health Center (NWHC). To report mortality or if you would like specific information on these mortalities, contact one of the following NWHC staff: Western US Kathryn Converse; Eastern US--Kimberli Miller; Hawaiian Islands--Thierry Work. Phone (608) 270-2400, FAX (608) 270-2415 or E-mail kathy_converse@usgs.gov. National Wildlife Health Center, 6006 Schroeder Road, Madison, WI

Quarterly Mortality Reports

NOTE:
Effective October 1, 1996, the National Wildlife Health Center ceased differentiating its mortality reports by geographic region. The mortality table accompanying this report, therefore, lists all events by state in alphabetical order.

There were 36 reports this quarter. Avian cholera was the cause of mortality at multiple sites in Nebraska and California. Waterfowl populations migrating through Nebraska's Rainwater Basin this spring peaked at 3-4 million birds. Mortality was first observed in the beginning of March, and state wildlife and U.S. Fish and Wildlife personnel collected 3,428 birds, primarily snow geese with other goose and dabbling duck species. Merced NWR, California also reported high mortality due to avian cholera this quarter. Over 4,000 waterfowl, primarily coots, died with a peak of 300-400 birds collected per day.

Salton Sea in north-central California reported low level mortality in three groups of migratory birds. About 25 white pelicans and other fish-eating birds found sick or dead on the south end of the Sea the second week of March were confirmed with botulism type C. There was concern that botulism could cause major losses of pelicans similar to the large botulism mortality event last fall. About 2,100 dead and affected eared grebes were found at the northwest end of the Sea exhibiting the same abnormal behaviors that grebes have shown in past die-offs at Salton Sea; preening excessively, coming out of the water to preen on land, and congregating at freshwater outlets to drink. The cause of this mortality and unusual behavior remains undetermined. A small group of about 20 snow and Ross' geese, were found dead in fields and on freshwater areas in February on the south end of the Sea. Avian cholera was suspected as the cause of mortality but diagnostic evaluation showed no evidence of the disease.

Southern Utah reported the deaths of 1,900 eared grebes due to trauma. Apparently, the grebes became disoriented during a snowstorm and mistook snow covered fields and streets as water and attempted to land. Over 2,700 grebes were rescued and returned to a nearby refuge. Similar events have been documented several times in the last 20 years, the most recent during the winter of 1991.

A lightning strike was diagnosed as the cause of death for 52 snow geese near Columbus, Kentucky. All of the birds examined had fractured vertebrae and extensive internal hemorrhage with no evidence of an infectious process or gunshot wounds. Murray State University reports that broken back syndrome has been documented in geese in previous lightning strike events.

Over a period of four months, four bald eagles died and five became sick after feeding on euthanized carcasses deposited in landfills in Polk and Volusia County, Florida. Analysis of stomach contents and blood samples revealed pentobarbital as the cause of the morbidity/mortality. Surviving eagles were placed under the care of the Florida Audubon Society. The responsible parties were informed on proper disposal of euthanized animals.

Over three hundred passerines died in the area of Zion National Park, Utah. Homeowners reported an estimated mortality of 3-4 birds per day at bird feeders. Salmonella sp. was isolated from several of the birds submitted for diagnostic evaluation. This marks the first documented report of significant passerine mortality due to salmonellosis in Utah. Large-scale events occurred east of the Rocky Mountains in 1993/94 and west along the Northern Pacific Coast in 1992/93.

For additional information please contact Dr. Scott Wright, USGS National Wildlife Health Center - Disease Investigations Branch Chief, at 608-270-2460 or Paul Slota, USGS National Wildlife Health Center - Support Services Branch Chief at 608-270-2420.