Office of Fish and Wildlife Health and Forensics - May 2001 Report
Douglas E. Roscoe, Ph.D., Research Scientist
The Office of Fish and Wildlife Health and Forensics (OFWHF) conducts investigations and research on diseases of captive and free-ranging fish and wildlife. It also performs tests and analyses of biological samples for law enforcement cases. Diagnostic services and treatments of the fish stocks at the Hackettstown and Pequest hatcheries are a continuing function of this office.
No Contamination of Water with Lead from Black River Trap Range
Concerns over possible movement of lead deposited by trap range operations at the Black River Wildlife Management Area hunter education range prompted studies by OFWHF scientists. Lead from the shot in the shot-fall zone is not moving in the soil column and is not moving in runoff into surface or ground waters at or adjacent to the Black River Wildlife Management Area hunter education range.
West Nile Virus Surveillance 2001
West Nile Virus (WNV) surveillance for 2001 will focus on crows submitted to the NJ State Department of Health and Senior Services Laboratory, since they preceded human cases last year and represent a good sentinel species for virus activity. Over 45% of the crows tested were positive for WNV. The 20% prevalence of West Nile Virus in Red-tailed hawks in last year's submissions suggests these birds may be contracting the disease from eating crows. Laboratory tests at the Centers for Disease Control and the National Wildlife Health Center have demonstrated the transmission of WNV among birds through eating the virus. The Cooper's hawk had only a 3% prevalence among those submitted for testing. This hawk feeds on smaller birds, which relative to crows are rarely infected with the virus. Funding from the Department will be used to expand the testing of falcons and hawks this spring, summer and fall. Last year's results suggest hawks will begin being infected in late August with most being infected in September and diminishing in October.
Survey of Falcons and Hawks for Chlordane Poisoning
Brain samples from 85 birds of prey were analyzed for chlordane and other chlorinated pesticides. Chlordane poisoning was diagnosed in American kestrels, a broad-winged hawk, Cooper's hawks, a great horned owl, a merlin, red-tailed hawks and sharp-shinned hawks. This persistent pesticide in the soil accumulates in the tissues of resistant Japanese and oriental beetles and in starlings and grackles which eat them. The hawks and falcons eat the contaminated birds or the beetles themselves. A 39% prevalence of chlordane poisoning was recorded for 36 Cooper's hawks examined at the OFHWF pathology and toxicology labs.
Atlantic Brant Die-off Update
A USGS National Wildlife Health Laboratory pathologist reports the finding of a reo-like virus in an Atlantic brant which had been shot in Maryland. Lesions in that brant were similar to those in the NJ die-off. Reo-viruses are difficult to culture. If future die-offs occur the initial focus will be to collect specimens suitable for isolation of that bird virus.
Foot and Mouth Disease
Over 1 million livestock have been slaughtered in England to control the spread of the animal virus responsible for foot and mouth disease. The virus infects cattle, sheep, goats, pigs, water buffalo, Cape buffalo and white-tailed deer. The foot and mouth disease (FMD) free status of the US livestock industry is threatened by introduction of this disease. Ten white-tailed deer have been experimentally exposed to FMD. Four died, those that survived shed virus for 4 weeks and one shed virus for 11 weeks. Therefore, whitetails figure prominently in the maintenance of this disease if it were to be introduced into free-ranging deer. Keeping it out is part of the planning activity of the NJ Foot and Mouth Disease Task Force which is led by the NJ Department of Agriculture, Division of Animal Health and is comprised of veterinarians, scientists and personnel from various state and federal agencies (NJDOA, USDA, NJDEP, NJDOT, NJ Nat. Guard, NJSP, Rutgers University). The OFWHF supervisor, Dr. Douglas Roscoe, is representing the Division of Fish and Wildlife on that task force. The USDA web site www.aphis.usda.gov/oa/fmd/index.html gives current information on the status of FMD.
