(e) = estimate; * = morbidity and mortality

National Wildlife Health Center (NW); Southeastern Cooperative Wildlife Disease Study (SC); University of Nebraska - Lincoln, Veterinary Diagnostic Center (NE); California Department of Fish and Game - Wildlife Investigations Laboratory (CA).

Written and compiled by Gregory Kidd, 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, e-mail: kathy_converse@usgs.gov., or for Hawaiian Islands contact Thierry Work. Phone: (608) 270-2400, FAX: (608) 270-2415 or write USGS National Wildlife Health Center, 6006 Schroeder Road, Madison, WI 53711.

Quarterly Mortality Reports

The following highlights wildlife mortality reported to the National Wildlife Health Center (NWHC) from October through December, 1995. Twenty nine die-offs were reported to NWHC this quarter.

As is typical for this time of year, avian cholera epizootics accounted for the greatest losses. The largest die-off occurred at the Sacramento National Wildlife Refuge Complex in California and involved over 5,000 waterfowl. Mortality began at Butte Sink NWR in early November and later in the year occurred on the other Sacramento Complex refuges (Colusa, Delevan, Sutter, Sacramento River, and Sacramento). Mortality continued into early February. NWHC research personnel have been on site collecting environmental data as part of an avian cholera research project. Avian cholera also caused the death of an estimated 1,000 eared grebes and Canada geese using the Great Salt Lake in Utah. Avian cholera occurred for the first time on this area last year with losses estimated at 10,000 eared grebes and ruddy ducks. In Scotts Bluff County, Nebraska, approximately 800 waterfowl, primarily mallards, died on an open creek and a nearby ten acre pond. Low level mortality is ongoing. This site is within 1/2 mile of an area where avian cholera occurred in 1985. Avian cholera mortality has not been reported again until this year.

Conjunctivitis in house finches continued in several Eastern states this quarter. Sick birds were reported from a new location in Kenton County, Kentucky. At that site, approximately 50% of the birds visiting a backyard feeder were noted with red, crusty eyes. A single bird that was collected and necropsied, showed lesions typical of the conjunctivitis in house finches from previously documented sites. Mycoplasma cultures were positive, however, the fragile organism could not be maintained so typing was not possible.

Lead poisoning caused the death of an estimated 60 waterfowl in Lassen County, California. The area consists of flooded rice and alfalfa fields. It is speculated that the source of the lead was from lead shot spent in blackbird control operations.

An estimated 1000 Northern fulmars died along the Pacific coasts of Washington and Oregon. The mortality estimates were based on shoreline surveys and with much of the shoreline inaccessible in this area, the estimate is crude. The definitive cause of mortality is not yet known but diagnostic testing is ongoing. So far there is no evidence that infectious or toxic diseases played a role in the event. It is not uncommon to find groups of dead fulmars and other seabirds following storm events in the months of November and December, however, the magnitude of the mortality in fulmars this year is unusual.

Aspergillosis was determined to be the cause of death for an estimated 750 mallards found along a one mile stretch of Winters Creek in Scottsbluff, Nebraska. Mallards were found in a similar condition 2.5 miles away on Lake Minatare. As many as 27 bald eagles were seen feeding on the carcasses which, in conjunction with the poor ice conditions, hampered collection.

Renal coccidiosis was determined to be the cause of death for 136 double-crested cormorants in Runnells Bottoms, Marion County, Iowa. This is the first time this disease has been reported in Iowa and it has only been documented six times (1-NE; 1-MN; 5-KS) previously in double-crested cormorants. Since the 1992 Newcastle outbreak, cormorant mortality has been monitored closely.

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.