(e) = estimate; * = morbidity and mortality

National Wildlife Health Center (NW); Southeastern Cooperative Wildlife Disease Study (SC); California Department of Fish and Game - Wildlife Investigations Laboratory (CA); Florida Marine Research Institute (FL); New York State Department of Environmental Conservation (NY).

Written and compiled by Gregory Kidd, NWHC. The Quarterly Wildlife Mortality Report is available at http://www.nwhc.usgs.gov. To report mortality or receive information about this report, contact the above NWHC staff, e-mail: kathy_converse@usgs.gov., or for Hawaiian Islands contact Thierry Work. Phone: (608) 270-2400, FAX: (608) 270-2415 or write USGS National Wildlife Health Center, 6006 Schroeder Road, Madison, WI 53711.

Quarterly Mortality Reports

The following highlights wildlife mortality and morbidity events reported to the National Wildlife Health Research Center (NWHC) from January through March, 1996. For ease of agency reporting, the table will be ordered by state rather than flyway or region.

Avian cholera was the predominant disease again this winter, accounting for all six die-offs in California. Salton Sea National Wildlife Refuge (NWR), a past site of avian cholera die-offs, reported that mortality was primarily in ruddy ducks using an area north of the Alamo River. Humbolt Bay NWR, on the coast of northern California, reported that at least 930 of 1,500 coots on the refuge died of avian cholera. Fortunately, only a few of the estimated 10,000 ducks present were affected. There were two distinct peaks of avian cholera mortality at the Lower Klamath NWR in northern California. In early December, avian cholera mortality occurred at low levels throughout the refuge in several species of ducks. As duck mortality subsided in early January, mortality began in swans. Necropsy examination of tundra swans and a few trumpeter swans that were initially suspected to have died from lead poisoning, confirmed avian cholera as the cause of death. Based on past history, refuge staff suspect that some of the swans did die of lead poisoning.

Near Kearney, Nebraska, in the Rainwater Basin, 6,170 snow geese, 1,096 northern pintails and 1,561 other ducks and geese were collected on two areas where avian cholera has occurred in the past. At this site, an estimated one million snow geese were crowded into limited open water creating ideal conditions for the transmission of avian cholera.

Scientists from several agencies, headed up by the Florida Marine Research Institute in the Florida Department of Environmental Protection, are seeking clues to the cause of death for 155 manatees found between Englewood and Marco Island, Florida. Their investigation includes evaluation for a biotoxin associated with red tide occurring in the mortality area, infectious disease agents or other toxins.

Storm related trauma was reported in several species following a blizzard that struck the midwest in late March. A rainstorm that quickly changed into a snowstorm with winds in excess of 60 mph contributed to the death of 2,000 sandhill cranes in Nebraska's Rainwater Basin, 7,000 coots and ducks in northern Iowa and 9 Canada geese in Hustisford, Wisconsin. It is speculated that high winds and poor visibility may have caused birds to fly into powerlines, trees and other objects causing their death. There were also unconfirmed reports of storm related mortality of waterbirds and migrating passerines in surrounding states.

The New York State Department of Environmental Conservation (NYDEC) reported several cases of diazinon poisoning that occurred last year. All avian mortality was thought to be inadvertent and associated with the approved application of pesticides. The NYDEC also reported a suspected intentional misuse of carbofuran at a cattle feedlot that resulted in the death of three species of passerines.

The J.B. Hansen NWR, on the Oregon-Washington border, reported mortality in one of four subpopulations of endangered Columbian white-tailed deer. Higher than expected mortality occurred on Tenasillahee Island where deer populations have been increasing. Necropsies performed in the field revealed that most deer were emaciated with no body fat reserves and reduced muscle mass and light to moderate parasite loads. One contributing factor to this emaciation is increasing demands on food resources on the island caused by increasing numbers of migrating waterfowl during winter and an increasing nutria population.

Conjunctivitis, assumed to be caused by a mycoplasmal organism, continues to cause illness in house finches. New observations of conjunctivitis in house finches in Indiana, Illinois, Michigan, Wisconsin and Missouri indicate the disease is slowly spreading westward. In addition to house finches, Maryland and Virginia have reported conjunctivitis in goldfinches and purple finches. Investigation continues into the spread of this disease and the impact on bird populations.

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.