(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); New York State Department of Environmental Conservation (NY).

Written and compiled by Kathryn Converse, Kimberli Miller, Linda Glaser, Terry Creekmore, and Audra Schrader, 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 53711.

Quarterly Mortality Reports

Salton Sea in southern California has been the site of multiple mortality events this quarter involving several migratory species. Botulism type C was again diagnosed and about 870 white and brown pelicans, herons, egrets, terns, gulls, and other birds died from March through mid July. Monitoring was increased this summer after over 14,000 birds died of botulism type C last fall. In addition, over 2400 eared grebes died after exhibiting excessive preening, leaving the water to preen on shore and congregating at freshwater outlets to drink. Despite extensive field and diagnostic evaluations the cause of this mortality remains undetermined and appears to be simular to previous mortality events that occurred in eared grebes over the last five years. A cormorant colony on Mullet Island in southern Salton Sea was found abandoned in mid May during routine surveillance activities. An investigation was launched and over 1600 nestling and fledgling cormorants were found dead. Many older juvenile cormorants observed along the shores of Mullet Island, exhibited neurological signs including wing or leg paralysis, generalized weakness or inability to move. Histopathology showed a non-suppurative encephalitis and NWHC isolated a Newcastle disease virus from cormorant tissues. Strict biosecurity measures were initiated to minimize transmission of this highly infectious virus to other birds. Meanwhile, the virus was pathotyped by the USDA National Veterinary Services Laboratory as a mesogenic Newcastle disease virus, moderate in terms of its pathogenicity to domestic chickens.

Duck plague was confirmed as the cause of death of muscovy ducks collected at two sites in residential Virginia Beach, Virginia. There is a history of duck plague outbreaks in this area. Duck plague was confirmed in a third waterfowl die-off in a private aviculturalist's flock in Poquoson, Virginia, near Chesapeake Bay. Approximately half of 60 penned ducks and geese (pinioned shoveler, pintail, wigeon, gadwall, manduran, wood and black ducks and Canada geese) died over a 2 week period. One pen was completely enclosed but free-flying waterfowl frequently entered the other pen.

The New York Department of Environmental Conservation (NYDEC) diagnosed hemorrhage secondary to parasitism by Sphaeridiotrema globulus as the cause of death for over 100 snow geese found along the Hudson River in Schuylerville, New York. A similar event five years ago was diagnosed as parasitism by S.globulus.

Approximately 65 egrets, herons of five species, and a variety of other water birds and passerines, washed up along a 10-15 mile stretch of beach in Collier County, Florida. Mortality was attributed to a regional storm a few days prior to the detection of dead birds. However, cattle egrets and a sora rail submitted to NWHC and rails and cuckoos submitted to Florida State Laboratory for necropsy were in good body condition with empty stomachs and no evidence of trauma or drowning. The cause of death remains open.

Over 500 nesting adult common murres were collected along a 60 mile section of Oregon and Washington coast from June through mid July. Mortality was estimated to be much higher along the total coastline from Coos Co. Oregon to Grays Harbor Co. Washington. Many of the murre nesting colonies were abandoned or had poor production. Birds examined at NWHC were emaciated with no evidence of infections or parasitic disease. Murre mortality was preceded by several days of intense winds and high sea surface temperatures. Similar environmental conditions were noted during a 1996 mortality event.

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.