(e) = estimate; * = morbidity and mortality
National Wildlife Health Center (NW); University of Illinois (UIL); Illinois Department of Conservation (IL); Rose Lake Wildlife Disease Center - Michigan (RL); Minnesota
Department of Natural Resources (MN); Tri-State Bird Rescue & Research Inc. - Newark, Delaware (TS); Wisconsin Department of Natural Resources (WI); Southeastern
Cooperative Wildlife Disease Study (SC); Alberta Natural Resources Service (ALB); California Department of Fish and Game - Wildlife Investigations Laboratory (CFG); Idaho
Department of Fish and Game - Wildlife Health Laboratory (ID).
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.
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The following
highlights wildlife mortality reported to the National Wildlife
Health Center (NWHC) from July to September 1995. Seventy two epizootics
were reported this quarter; botulism accounted for 63% with losses
of more than 249,000 birds.
The Canadian
Province of Alberta's Natural Resource Service reported that an
estimated 200,000 ducks, shorebirds, raptors, herons and gulls,
died from botulism type C on Pakowki Lake (native for "bad water")
in southeast Alberta. Botulism caused the death of 31,000 waterfowl
on this shallow lake in 1994. This is the largest reported loss
of waterfowl in Alberta. It is speculated that blue-green algae
poisoning may have been a contributing factor. Despite regular carcass
pickup, mortality remained very high (5,000 birds/day) throughout
August. A task force is being set up to examine options for management
to attempt to deter such losses in future years.
In late July,
NWHC received a report of gull mortality on Lake Sakakawea in North
Dakota along the shore of a recreational area. Over 200 sick or
dead gulls were collected around a boat ramp, fish cleaning station
and picnic area. Clinical signs included lethargy, hunched stance,
droopy wings and crusty eyes. Chlamydiosis was suspected in the
gulls because an outbreak of chlamydiosis occurred in 1986 in gulls
nesting on islands in this lake. Two of thirteen carcasses necropsied
at NWHC had gross lesions suggestive of chlamydiosis, however, Chlamydia
was not isolated by the USDA, National Veterinary Services Laboratory.
Salmonellosis and botulism type C were diagnosed in two gulls. Approximately
280 carcasses were collected and incinerated using precautions to
reduce the potential of exposure to chlamydia, a human pathogen.
The California
Department of Fish and Game, Wildlife Investigation Laboratory reported
mortality in desert bighorn sheep in the Old Dad Mountains, San
Bernardino County, California. Twenty five sheep were found dead
in the vicinity of a guzzler (a water catchment system for the sheep)
and thirteen decomposing lambs were found inside the water tank.
Type C botulism toxin was detected in the heart blood of the one
sheep suitable for necropsy. Type C toxin was also detected in fly
larvae collected from dead lambs inside the tank, although all water
samples were negative. Investigators speculate that Clostridium
botulinum toxin was produced in the lambs that drowned. Toxin present
in either the water or fly larvae was then consumed by adult sheep
using the guzzler. This is the largest documented mortality event
in desert bighorn sheep and the first report of type C botulism
in this species.
Steatitis was
confirmed in immature great blue and black-crowned night herons
that died between April and September, 1995 in Los Angeles and Orange
Counties, California. Despite extensive field investigations by
the US Fish and Wildlife Environmental Contaminants personnel and
personnel from the Long Beach Naval Station, the etiology of this
disease remains unknown. The cause of steatitis diagnosed in herons
submitted from Point Loma, California in 1993 and 1994 also remains
a mystery.
In mid-July
1995, a research scientist from NWHC traveled to Banks Island, Northwest
Territories, Canada as part of an ongoing avian cholera project.
Collaborating Saskatchewan graduate students on site reported that
an estimated 15,000 snow geese and a few jaegars, cranes and gulls
died between June 15 and July 5. Research personnel submitted bones
of decomposed geese to NWHC. Pasteurella multocida, serotype 1,
was isolated from 12/40 bone marrow samples.
Tri-State Bird
Rescue and Research reported mortality associated with a spill of
approximately 500 barrels of a relatively light, highly paraffinic
crude oil, at a dock in Westville, New Jersey. Of the 65 oiled birds
collected and treated, only five died from oil exposure. Successful
treatment of oiled birds was due to the type of oil spilled and
rapid response by Tri-state, the owners of the dock, the US Fish
and Wildlife Service and concerned citizens.
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.
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