(e) = estimate; * = morbidity, not mortality

New York State Dept. of Environmental Conservation (NY), Southeastern Cooperative Wildlife Disease Study (SCW), USGS National Wildlife Health Center (NW), Colorado State University (CO), Florida Game and Fish (FL), Illinois Department of Natural Resources (IL), Maryland Diagnostic Laboratory (MD), Wyoming Game and Fish (WY), National Forensics Laboratory (NFL), Iowa State Diagnostic Laboratory (IA), Canadian Cooperative Wildlife Health Center (CCW), Environment Ministry Laboratory of Toronto (TOR), Center for Disease Control (CDC), various state laboratories (ST), Nevada Division of Wildlife (NV), Washington State Diagnostic Laboratory (WA), B.C. Ministry of Environment (BC).

Written and compiled by Christine Lemanski, Kathryn Converse/Rex Sohn - Western US, 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

Trematode-related Mortality Recurs at Upper Mississippi River National Wildlife Refuge.
For the third consecutive fall, an estimated 2,300 lesser scaup, American coots, and other waterfowl were reported dead by hunters and Upper Mississippi NWR personnel. Waterfowl and coots were found along the shoreline and on islands in the Mississippi River from the end of September until mid-December, with the majority of deaths recorded in early October and early November. Snails were collected by NWHC staff at the refuge from June through October. In some locations, over 50% of the snails were infected with stages of the trematodes, and the highest prevalence was detected in June. Infections by the trematodes Cyathocotyle bushiensis and Sphaeridiotrema globulus were identified in both chilled and frozen carcasses submitted to NWHC. These two trematodes species have been implicated in the death of over 10,900 water birds at Upper Mississippi NWR during the spring and fall migrations since 2002.

West Nile virus completes spread across continental U.S. in 2004.
Since it was first detected in 1999, West Nile virus (WNV) has quickly spread across the North American continent into Canada, Mexico and into several Caribbean areas. In 2005, the sixth WNV season, WNV arrived in Oregon and thus completed its spread into the 48 continental U.S. states. Interestingly, although 2 dead birds and 2 horses were found with WNV infection in 2002, the state of Washington has not since been detected WNV within their borders despite dead bird, mosquito, equine and human surveillance. In 2005, many areas again reported WNV activity, with southern California and Maricopa County, AZ reporting high activity. As of January 13, 2005, over 7300 avian, 1400 equine, and 2500 human cases have been reported to the CDC and on state websites. The list of species in which WNV has been detected continues to grow and currently has 289 wild and captive avian, 23 mammalian and 1 reptilian species. With the end of the 2004 WNV season, state and local surveillance programs have already begun planning their 2005 WNV surveillance programs.

Avian Cholera in Eared Grebe on the Great Salt Lake.
In late October 2004 Utah Division of Wildlife Resources (UDWR) personnel contacted the NWHC to report the observation of an estimated 30,000 sick (1%) and dead (99%) eared grebes on the main body of the Great Salt Lake. The total estimated population of eared grebes on the lake was 500,000. Chilled and frozen carcasses were submitted to the NWHC for diagnostic evaluation. All of the grebes examined had similar lesions - focal liver necrosis, mucoid intestinal content, and pulmonary congestion. Pasteurella multocida was isolated from tissues of all birds tested. Previous outbreaks of avian cholera on the Great Salt Lake were documented in 1994, 1995, 1998, and 2002 with estimated losses ranging from 1,000 to 44,000 birds, mostly eared grebes. Personnel of the UDWR and U.S. Fish and Wildlife Service continued to monitor the situation until early December when the die-off ended. Due to low lake levels and favorable wind conditions the majority of dead birds remained in high salinity, deep water areas of the lake away from freshwater wetlands on the south and east shores. Therefore, the extensive, labor-intensive carcass pickup and disposal efforts that were implemented during the severe 1998 die-off did not become necessary in this incident.

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.