(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), Wisconsin Dept. of Natural Resources (WI), Centers for Disease Control and Prevention (CDC), Various states labsites (ST), Alabama Veterinary Diagnostic Laboratory - Auburn (AL), Environment Ministry Laboratory of Toronto (TOR), Florida Game and Fish (FL), San Diego County Veterinary Diagnostic Laboratory (CDL), Sea World of San Diego (SWD), Iowa Department of Natural Resources (IA), Illinois Department of Natural Resources (IL), Louisiana Department of Wildlife and Fisheries, Maryland Department of Natural Resources (MD).

Written and compiled by Rex Sohn -Western US, Kathryn Converse- Central 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

Avian Botulism at Lower Klamath National Wildlife Refuge.
In late July 2004, U.S. Fish and Wildlife Service (FWS) personnel reported the mortality of 5,000 birds at Lower Klamath NWR within the previous 10 days. Primarily dabbling ducks were affected, but some coots, grebes and ibis also died. Sick birds showed signs consistent with botulism (resting head on back, lying at water's edge on mudflats or vegetative mats, sick and fresh dead birds clustered around maggot covered carcasses). Botulinum type C toxin was confirmed by mouse inoculation tests in ducks submitted to NWHC for diagnostic evaluation. There were approximately 200,000 resident and migrant waterfowl and 20,000 shorebirds at risk at the onset of the die-off and the number of birds increased as migratory birds arrived from the North over the next two months. Many of those birds were concentrated on a few wetlands where water was maintained despite an ongoing drought. Avian botulism has been a recurring problem at Refuges in the Klamath Basin NWR Complex for many years. Refuge staff carry out aggressive surveillance and carcass pickup during the expected botulism season. Botulism has been confirmed or suspected at Lower Klamath NWR every year since 1980 with the exception of 1982, 1983, 1993, and 2002. Reported losses of birds during botulism outbreaks during that time period ranged from 300 to 14,000 birds.

Marine Bird Mortality in the Eastern Aleutian Islands.
A die-off of marine birds including puffins, gulls, kittiwakes, common eiders, and pelagic cormorants and flat fish (flounder) was first observed in early July by residents of False Pass, Alaska on the extreme east end of the Aleutian Island chain. The weather at the time of the die-off was unusually warm (60 - 70 degrees F.) and sunny with light wind. The location is in a strait connecting the Bering Sea with the Pacific Ocean and there is a strong tidal current which carried the birds ashore. Specimens of dead birds were collected and frozen by Tribal government personnel then transferred to U.S Fish and Wildlife Service biologists at Izembek NWR who arranged shipment of the specimens to the NWHC for diagnostic evaluation. Dead carcasses continued to appear on the local beaches for two weeks with an estimated total mortality reaching 1,000 birds. Diagnostic evaluation of tufted puffins, a pelagic cormorant, and a black-legged kittiwake showed birds were in fair body condition with some lung edema but had no other significant gross or microscopic lesions. Bacterial cultures of lungs yielded no pathogenic bacteria and viral cultures of brains, lungs, and intestines were negative. No significant parasite infections were observed in GI tracts. Upper GI contents and tissue samples were submitted to the Center for Marine Science at the University of North Carolina-Wilmington for marine biotoxin analysis, which determined the levels were within normal levels for marine birds. The NWHC has only three reported mortality events in tufted puffins since 1975. One event was in the Gulf of Alaska in 1989 and the other two events were on the Washington coast in 1991. The primary diagnosis in the Alaska and one Washington die-off was emaciation while the primary diagnosis in the second Washington die-off was suspect petroleum toxicosis.

Pelican and gull mortality in North Central nesting colonies.
For the third consecutive year, there were higher than expected losses of pelican chicks in three nesting colonies in South Dakota, Montana and Minnesota. Losses ranged from 100's to 1000's. More than half of the North American white pelicans are produced in these colonies. A high number of pelicans necropsied from each site were positive for West Nile virus and some birds were also positive for Salmonella sp. or botulism type C. Histopathologic examinations are in progress to determine if West Nile virus was the cause of death in these pelicans. A two year research study is in progress in two of these states to determine the possible impact of West Nile virus on the nesting pelican colonies. Mortality was also reported in two gull nesting colonies in North Dakota. Salmonellosis was confirmed in some of the gulls submitted for necropsy from one colony. Similar gull mortality occurred in North Dakota nesting colonies for the past three years.

Terns in New England.
In July and August 2004, staff and researchers at Seal Island National Wildlife Refuge (NWR) in Maine and staff at Monomoy NWR and Cape Cod National Seashore (NS) in Massachusetts reported sick and dead fledgling common terns. Seal Island terns were unable to raise or extend one wing, while those in Massachusetts were unable to fly and were circling, star-gazing, and unable to maintain their balance. At necropsy, the primary consistent finding was atrophy of immune system organs (thymus, bursa of Fabricius, spleen) in birds from all three sites. No viruses were isolated in multiple systems, and investigations are continuing to determine the cause of the immune organ atrophy. Many specimens from Massachusetts tested positive for Salmonella typhimurium (Copenhagen); these bacterial infections may be opportunistic due to immune system impairment. Mortality estimated from collected or buried tern carcasses was 1,700 in Massachusetts, making this the largest tern mortality event in the NWHC epizootic database.

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.