(e) = estimate, ** Mortality subject to change pending transect data, *** Mortality estimate not available at this time.
(s) = suspect, Diagnosis not finalized, but field signs and historic patterns indicate the disease

Canadian Cooperative Wildlife Health Center (CCW), Cornell University (COR), Houston Zoo (HZ), Hubbs Sea World Research Institute (HSW), Michigan Department of Natural Resources (MI), Minnesota Department of Natural Resources (MNS), New York State, DEC, Division of Fish, Wildlife & Marine Resources (NY), No Diagnostics pursued (NON), Other (OT), Pennsylvania State University Animal Diagnostics Lab (PSU), Southeastern Cooperative Wildlife Disease Study (SCW), Texas A&M Veterinary Diagnostic Laboratory (TVD), UC Davis (UCD), University of Pennsylvania (UPA), USDA National Animal Health Laboratory (AHL), USGS National Wildlife Health Laboratory (NW), Various state lab sites (ST), Wisconsin Department of Natural Resources Wildlife Health Lab (WI).

Written and compiled by: Mark Jankowski - Eastern US, Krysten Schuler - Western US, and Jennifer Bradsby - Technician.

To report mortality or receive information about this report, please contact the USGS National Wildlife Health Center, 6006 Schroeder Road, Madison, WI 53711:

Quarterly Mortality Reports

Avian cholera outbreaks in throughout California (CA)
Several counties in California have reported outbreaks of avian cholera in a variety of waterfowl beginning in mid-December and continuing presently. The most commonly afflicted species is American coot, but ruddy ducks, green-winged teal, widgeon, mallard, snow geese, and white-fronted geese have been affected. Aleutian Canada geese, removed from the endangered species list in 2001, were involved at the avian cholera outbreak at San Joaquin National Wildlife Refuge in Stanislaus County. Other refuges with avian cholera outbreaks include Butte Sink NWR in Sutter county, Colusa NWR in Colusa county, Sacramento NWR in Glenn county, and Salton Sea NWR in Imperial county. California Department of Fish and Game investigated mortality in Del Norte, Humboldt, and Sutter counties. Current mortality estimates are over 5000 birds. Many of these outbreaks are ongoing so final mortality numbers are not available.

Great Salt Lake mortality in eared grebes and northern shovelers (UT)
Avian cholera outbreaks at the Great Salt Lake gained national attention this year. There were two events, the first occurred in eared grebes near Promontory Point in November. Surveys conducted by Utah Division of Wildlife Resources estimated 15,000 eared grebes died out of a population of 1.5 million. Previous significant outbreaks occurred in 1994 where 15,000 grebes died; 44,000 in 1998; 30,000 in 2002; and 30,000 in 2004. This event appeared to subside around the beginning of December. A second event started mid-December about 15 miles away near the town of Saltair, Utah. The second event primarily involved northern shovelers with some California gulls and green-winged teal. An estimated 1,500 northern shovelers succumbed to avian cholera. The majority of mortality seemed to be over by the end of the year. Several media sources picked up the story, including the New York Times and Salt Lake Tribune. More information on avian cholera and links to news stories are available here.

Type E botulism claims thousands of birds in 4 of 5 Great Lakes during 2007
As in recent years, botulism type E was responsible for the mortality of waterbirds resident to and migrating across the Great Lakes during the summer and fall of 2007. Botulism type E was detected in a small sample of the *6982 dead birds collected on the shores of Lakes Ontario (June – December; *1753 carcasses), Erie (July – December, 1694 carcasses), Huron (September – December, 44 carcasses), and Michigan (June – December, 3491 carcasses). The top 5 affected species were the ring-billed gull (2362), common loon (1458), double-crested cormorant (743), long-tailed duck (676), and horned grebe (354). Peak mortality occurred during October through December as fish-eating birds migrated southward, but there were avian botulism type E mortalities during the entire June to December period, including the death of 4 endangered piping plovers at Sleeping Bear Dunes National Lakeshore. The characteristics of the 2007 event were similar to botulism type E outbreaks that have occurred annually in at least one of the Great Lakes since 1998. Estimating total avian mortality, the event’s time-course in a lake, as well as the spatial extent the disease is difficult because efforts to detect and tally beached carcasses vary across the entire Great Lakes region. A systematic approach that is coordinated across many organizations is needed in order to track mortality. This would help to better understand the cumulative impact on bird populations, as well as the circumstances leading to the exposure of these varied avian species to botulinum type E toxin.

*This estimate is low because the New York Department of Environmental Conservation continues to analyze their transect data.

Range expansion of epizootic hemorrhagic disease in the eastern USA
Twenty-two states and the District of Columbia detected epizootic hemorrhagic disease (EHD) in white-tailed deer during the summer and fall of 2007. New York State’s first ever recorded case of EHD occurred October 2007 in white-tailed deer that were collected from Albany County; several more white-tailed deer from other NY counties were found positive into November 2007. It is not possible to determine total EHD-associated mortality because detection is generally opportunistic rather than through systematic surveillance. However, the extensive 2007 EHD outbreak resulted in a high number (approximately 300) of EHD-virus isolations at SCWDS and was found in multiple counties within the following states: AL, CO, DE, DC, GA, IL, IN, KS, KY, MD, MI, MO, NJ, NY, NC, OH, PA, SC, TN, TX, VA, WV, and WI. Cattle were affected in some of these states as well. Epizootic hemorrhagic disease virus presents similarly to bluetongue virus in the field, but these are distinct viruses. Therefore, in order to characterize the spatiotemporal progression of a particular virus outbreak, the serotype must be identified, rather than assuming that EHDV is present upon the observation of deer with a hemorrhagic disease. Information concerning this 2007 outbreak in the context of historical EHD patterns, as well as on EHD and bluetongue viruses is available in SCWDS BRIEFS, Vol. 23, Nos. 3 and 4.