(e) = estimate; * = morbidity, not mortality

B.C. Ministry of Environment (BC), California Fish and Game Wildlife Investigations Lab (CFG),  Centers for Disease Control and Prevention (CDC),  Florida Fish and Wildlife Commission (FL),  Florida Fish and Wildlife Research Institute, St. Petersburg, FL (FMR), International Bird Rescue Research Center (IBR),  National Veterinary Services Laboratory, Ames, IA (NVL), National Marine Fisheries Service (NMF), Oil Spill Response Team, (OSR), Oregon Dept. of Fish and Wildlife (OR),  San Diego County Veterinary Diagnostic Laboratory (SDC),  Southeastern Cooperative Wildlife Disease Study, Athens, GA  (SCW), University of Florida (UFL),  US Army, Fort Meade (USA),  U.S. Fish and Wildlife Service (FWS), USGS National Wildlife Health Center (NW), Wisconsin Dept. of Natural Resources (WI), Washington Animal Disease Diagnostic Laboratory (WA),  and Wyoming Game and Fish (WY)

Written and compiled by Rex Sohn -Western US, Kathryn Converse- Central US, Grace McLaughlin/Kimberli Miller - 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

Common Redpoll Mortality in Alaska due to Escherichia albertii. From late December 2004 to February 2005, the Alaska Department of Fish and Game received reports of dead common redpolls at back-yard bird feeders in the Fairbanks area.  The period of highest mortality coincided with a period of prolonged minus 40 C temperatures in late January. The common redpoll population at the beginning of the outbreak was estimated at 8,000 birds, which was a historic high for the area. Approximately 100 deaths were documented, although it is assumed that the actual death toll was considerably higher. There were no consistent gross post-mortem lesions and histologic lesions consisted mainly of mild enteritis. Although there were no anatomic changes to indicate septicemia, Escherichia albertii was isolated in high numbers and in pure cultures from the intestines and tissues of five redpolls that died during the peak of the die-off. All E. albertii isolates were indistinguishable by pulsed-field gel electrophoresis. The identification of E. albertii was established by 16S rDNA gene sequence and by phenotypic similarity to previously reported E. albertii isolates. Other birds, including redpolls, a black-capped chickadee, a crossbill, and a boreal owl that were known to have died of other causes were cultured as controls and were negative for E. albertii.  Escherichia albertii is a recently described member of the Enterobacteriaceae that has been associated with diarrheal illness in humans, but has not been previously associated with disease or infection in animals. The E. albertii isolated from these redpolls was very similar to the description of an atypical E. coli previously reported from a finch mortality event in Scotland.

Unusual Moose Morbidity and Mortality in Alaska.  A wildlife veterinarian and wildlife biologists from the Alaska Department of Fish and Game investigated morbidity and mortality in 7-10 month old moose calves that began in late December 2004 and continued until early April 2005. Most of the 25 mortalities occurred during or shortly after a two week period of extremely cold weather (minus 40 degrees C or colder) with deep snow.  Some of the calves died suddenly, while others were observed to be lethargic for a period of time before becoming recumbent and eventually dying.  Closer visual examination of dead animals showed emaciation, conjunctival edema, and enlarged abdomens.  Specimens collected from necropsied animals were submitted to several diagnostic laboratories and a contract wildlife pathologist for laboratory tests and histopathology. Cooperative efforts by the diagnosticians resulted in a diagnosis of
bacterial peritonitis and septicemia.  Further studies are in progress to identify the various bacterial agents involved and to determine if pre-existing migrations of parasites (Setaria sp.) in the calves may have played a role in the onset of disease.

Marine Animal Mortality. In late January 2005, fish kills were reported in association with a red tide or harmful algal bloom (HAB), in Southwest Florida. There were daily reports of fish mortality in different locations during February.  Thousands of fish representing at least 20 species were affected, including several Goliath groupers weighing 200-300 lbs.  In early March, the Florida Fish and Wildlife Research Institute began getting calls about dead manatees primarily in Charlotte, Lee, and Sarasota counties.  By the end of March, 38 manatees (of the 65 found dead that month) were confirmed to have brevetoxin toxicity through necropsy findings and levels of toxins in stomach contents and tissues.  While manatee mortality from the HAB dropped precipitously in the following months, to 5 in April, 0 in May, and 7 in June, fish kills continued, with more than 100 events reported in the region through the end of June.  The effects of the HAB were reported in an area extending from Pinellas County to the Florida Keys, a straight-line distance of more than 320 km (225 miles) and extended for varying distances offshore

Tern mortality in Massachusetts. Common tern mortality was first noted early June 2005 on South Monomoy Island, Massachusetts.  Over the next 3 weeks, approximately 40 terns were found sick and dead.  Affected birds were wobbly, stumbling and had drooping wings.  On necropsy, the carcasses ranged from emaciated to good body condition, there were no significant gross lesions, and bacterial and viral cultures were negative.  The mortality coincided with a “red tide” which occurred along the coasts of Maine, New Hampshire and Massachusetts.  Reportedly, a storm on May 7-8 provided suitable conditions for a large algal bloom.  Shellfish beds were closed to harvesting as a result.  Dolphin mortality occurred during the same time period and was also thought to be associated with the algal bloom. Biotoxin assays on tern samples are in process.  Interestingly, there is a published report of tern and gull mortality on Monomoy in 1978 that was determined to be due to paralytic shellfish poisoning associated with saxotoxin in shellfish (The Condor 1983: 338-345).

Unknown cause of seabird mortality along the Atlantic Coast. Unusual seabird mortality, reported in early June 2005, involved shearwater, terns and gulls along the Atlantic Coast from Assateague Island, Maryland to Brevard County, Florida.  Approximately 700 birds, primarily shearwaters, were found dead or sick along these shorelines.  Many sick birds were admitted to wildlife rehabilitation facilities or veterinary hospitals for care.  About 50% of the reports were from Florida, primarily Volusia and Brevard counties.  Multiple state and federal agencies were involved in responding to this event.  On necropsy, the only common finding was emaciation.  Unfortunately, since many of the species affected live offshore, by the time the carcasses washed ashore they were often decomposed which made examination and analysis difficult.  Many tests are still underway at the end of June.

Thousands of wood frogs die in Rhode Island. In April 2005, a wetland ecologist at the University of Rhode Island recorded egg masses with approximately 4 million larvae in a large pond area in Washington County, Rhode Island.  In early June, the tadpoles appeared normal, however, on a return visit in mid June, the ecologist found hundreds, possibly thousands of sick and dead wood frog tadpoles.  Tadpoles were at a late development stage and had all four legs.  Many sick tadpoles were lethargic, rolled on their sides, had red spots on their skin and were easily collected. At a visit 10 days later, no living tadpoles were found in the main pond. There were three lethargic painted turtles, a few sick grey tree frog tadpoles and spotted salamanders found in a nearby area.  Ranavirus was isolated from the grey tree frog tadpoles and salamanders submitted to NWHC for diagnostic evaluation.  It is suspected that Ranavirus was also the cause of death in the wood frog tadpoles.