(e) = estimate

New York State Dept. of Environmental Conservation (NYS), Southeastern Cooperative Wildlife Disease Study (SCW), USGS National Wildlife Health Center (NW), Wisconsin Dept. of Natural Resources (WI), University of Maine (UME), National Veterinary Services Laboratory (NVL), University of Florida Veterinary Medical Veterinary Medical Teaching Hospital (UFL), Center for Disease Control (CDC), Canadian Cooperative Wildlife Health Center (CCW), Nebraska Veterinary Diagnostic Laboratory (NEB), New York City Dept. of Health (NYC), Arkansas Livestock and Poultry (AR), Florida Fish and Wildlife Resources (KY), Montana Fish, Wildlife and Parks (MT), Oregon Dept. of Fish and Wildlife (OR), Virginia Dept. of Game and Inland Fisheries (VA), State Diagnostic Laboratories (ST).

Written and compiled by Kathryn Converse/Rex Sohn = Western US, Kimberli Miller/Grace McLaughlin - Eastern US, 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, or for Hawaiian Islands contact Thierry Work. Phone: (608) 270-2400, FAX:(608) 270-2415 or e-mail: kathy_converse@usgs.gov. USGS National Wildlife Health Center, 6006 Schroeder Road, Madison, WI 53711.

Quarterly Mortality Reports

Black-bellied Tree Duck Mortality in Texas. For the second consecutive year, mortality of newly hatched Black-bellied tree duck chicks was observed at La Sal Vieja in Willacy County, Texas. During daily observations, USFWS biologists recorded twenty broods containing 217 chicks leaving two nesting islands on this hyper saline inland lake; one hundred forty five (67%) of the 18-24 hour old ducklings died before reaching the mainland. A search of the nesting islands identified 40 additional dead chicks. Clinical signs observed in ducklings included convulsions and salt accumulation on feathers and around the eyes. Freshly dead carcasses were submitted to the NWHC for diagnostic evaluation. The brains from the ducklings had sodium concentrations of >2,000 ppm, wet weight, that are indicative of sodium toxicity.

Cormorant Newcastle Disease in Wisconsin, New York, Vermont. Cormorant Newcastle virus (CNV), also known as cormorant paramyxovirus-1, was isolated from several double-crested cormorants collected in Green Bay, Wisconsin; Lake Oneida, New York; and Lake Champlain in New York and Vermont. Morbidity and mortality were first noted among hatch-year cormorants in July 2003. Newcastle disease virus was isolated in Wisconsin cormorants by NWHC and in New York and Vermont cormorants by the USDA National Veterinary Services Lab (NVSL). NVSL provided molecular characterization of CNV in birds from all three states. In addition of cormorant Newcastle virus, trauma and Salmonella, Aspergillis and helminth infections were causes of death in cormorants from these colonies. Morbidity and mortality were low, with less than one percent of these young cormorants affected.

Trematode-related Mortality in Upper Mississippi River waterbirds. Since mid-September, over 3,000 American coots and ducks have died from infection by the trematodes Sphaeridiotrema globulus (snail host Bithynia) and Cyathocotyle bushiensis (host snail Planorbella). the mortality is concentrated in Pool 7 (Lake Onalaska) of the Upper Mississippi River National Wildlife Refuge. No Bithynia snails have been found in sampling at this site and the source for the birds is unknown. Sphaeridiotrema globulus was the most prevalent organism in birds necropsied at NWHC with levels as high as 1,500 trematodes per bird. Similar mortality caused by the same species of trematodes occurred at this site during the fall 2002 and spring 2003 migrations.

Tularemia in Wyoming rabbits. Mortality was reported in 15 cottontail and jack rabbits on the Seedskadee NWR in southwestern Wyoming from June through September. Tularemia was confirmed in two rabbits submitted to the NWHC in september. Wyoming Department of Health officials have been in contact with refuge staff. No human cases were reported. Similar mortality of about 15 rabbits also occurred during the summer of 2002.

West Nile virus in White pelicans. West Nile virus was the suspected cause of death of over 5,000 white pelicans during the summer of 2003 in the north central states of Montana, North and South Dakota, Minnesota, and Kansas. West Nile virus was confirmed in adult and immature birds but the greatest losses occurred in pre-fledgling pelicans still on the nesting colonies. Pelican chicks were observed to be in the areas with high densities of mosquitoes. The loss of young pelicans ranged as high as 68% at some colonies. During this same time period, West Nile virus was confirmed in 3,000 gulls in North and South Dakota and Minnesota; and low numbers of cormorants in Minnesota and Canada geese in North Dakota.