(e) = estimate; * = morbidity and mortality
Health Center(NW);Southeastern Cooperative Wildlife Disease Study
(SC); California Department of Fish and Game - Wildlife Investigations
Laboratory (CA); New York State Department of Environmental Conservation
compiled by Kathryn Converse, Kimberli Miller, Linda Glaser, Terry
Creekmore, and Audra Schrader, National Wildlife Health Center (NWHC).
To report mortality or if you would like specific information on
these mortalities, contact one of the following NWHC staff: Western
US Kathryn Converse; Eastern US--Kimberli Miller; Hawaiian Islands--Thierry
Work. Phone (608) 270-2400, FAX (608) 270-2415 or E-mail firstname.lastname@example.org.
National Wildlife Health Center, 6006 Schroeder Road, Madison, WI
Salton Sea in
southern California has been the site of multiple mortality events
this quarter involving several migratory species. Botulism type
C was again diagnosed and about 870 white and brown pelicans, herons,
egrets, terns, gulls, and other birds died from March through mid
July. Monitoring was increased this summer after over 14,000 birds
died of botulism type C last fall. In addition, over 2400 eared
grebes died after exhibiting excessive preening, leaving the water
to preen on shore and congregating at freshwater outlets to drink.
Despite extensive field and diagnostic evaluations the cause of
this mortality remains undetermined and appears to be simular to
previous mortality events that occurred in eared grebes over the
last five years. A cormorant colony on Mullet Island in southern
Salton Sea was found abandoned in mid May during routine surveillance
activities. An investigation was launched and over 1600 nestling
and fledgling cormorants were found dead. Many older juvenile cormorants
observed along the shores of Mullet Island, exhibited neurological
signs including wing or leg paralysis, generalized weakness or inability
to move. Histopathology showed a non-suppurative encephalitis and
NWHC isolated a Newcastle disease virus from cormorant tissues.
Strict biosecurity measures were initiated to minimize transmission
of this highly infectious virus to other birds. Meanwhile, the virus
was pathotyped by the USDA National Veterinary Services Laboratory
as a mesogenic Newcastle disease virus, moderate in terms of its
pathogenicity to domestic chickens.
was confirmed as the cause of death of muscovy ducks collected at
two sites in residential Virginia Beach, Virginia. There is a history
of duck plague outbreaks in this area. Duck plague was confirmed
in a third waterfowl die-off in a private aviculturalist's flock
in Poquoson, Virginia, near Chesapeake Bay. Approximately half of
60 penned ducks and geese (pinioned shoveler, pintail, wigeon, gadwall,
manduran, wood and black ducks and Canada geese) died over a 2 week
period. One pen was completely enclosed but free-flying waterfowl
frequently entered the other pen.
The New York
Department of Environmental Conservation (NYDEC) diagnosed hemorrhage
secondary to parasitism by Sphaeridiotrema globulus as the cause
of death for over 100 snow geese found along the Hudson River in
Schuylerville, New York. A similar event five years ago was diagnosed
as parasitism by S.globulus.
65 egrets, herons of five species, and a variety of other water
birds and passerines, washed up along a 10-15 mile stretch of beach
in Collier County, Florida. Mortality was attributed to a regional
storm a few days prior to the detection of dead birds. However,
cattle egrets and a sora rail submitted to NWHC and rails and cuckoos
submitted to Florida State Laboratory for necropsy were in good
body condition with empty stomachs and no evidence of trauma or
drowning. The cause of death remains open.
Over 500 nesting
adult common murres were collected along a 60 mile section of Oregon
and Washington coast from June through mid July. Mortality was estimated
to be much higher along the total coastline from Coos Co. Oregon
to Grays Harbor Co. Washington. Many of the murre nesting colonies
were abandoned or had poor production. Birds examined at NWHC were
emaciated with no evidence of infections or parasitic disease. Murre
mortality was preceded by several days of intense winds and high
sea surface temperatures. Similar environmental conditions were
noted during a 1996 mortality event.
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.