From the December 2013 Conservationist
Wildlife Health Corner
DEC's Pathology Center
By Dr. Krysten Schuler
Each year, concerned New Yorkers come across sick, injured, or dead wildlife and wonder what, if anything, they should do. In some mortality cases, animals are sent to DEC's Wildlife Health Unit in Delmar to determine the cause of death. Using the latest laboratory and diagnostic techniques, biologists begin to unfurl the mysteries of what happened to these animals, how and why, and what can be done about it.
DEC wildlife biologist Kevin Hynes
demonstrates proper necropsy tech-
niques to DEC field staff.
New York State has long been involved in wildlife disease investigation. In fact, DEC was one of the earliest state agencies to study wildlife health, beginning in the late 1930s. Since the outset, this work has been headquartered at DEC's Wildlife Resource Center in Delmar. Staff there have made important contributions to our knowledge of infectious and parasitic wildlife diseases, and have been in the forefront nationwide in identifying threats to wildlife posed by pesticides, lead and environmental pollution.
Due in large part to the region's important role in global trade, New York is recognized as an epicenter for the emergence of wildlife diseases. During the last two decades, New York State was "ground zero" for North American outbreaks of both West Nile virus in birds, and white-nose syndrome in bats. In addition, New York has experienced an invasion of a raccoon-adapted strain of rabies, dealt with a detection of chronic wasting disease in deer, and seen the re-emergence of type E botulism in the Great Lakes with the subsequent death of thousands of diving waterbirds along Lake Erie and Lake Ontario shorelines. (See June, 2002 Conservationist.)
Kevin Hynes performs a necropsy on an
American crow, a known carrier of West
Nile Disease. Tissue samples are
collected and sent to labs for analysis.
As you can see, there's plenty to monitor and study when it comes to wildlife diseases and health! And some diseases are transmittable to humans as well. This is the case with the West Nile virus, a blood-borne disease carried by mosquitoes that commonly affects crows and jays, that can also affect horses and threaten human health. West Nile is an excellent example of a disease that intertwines wildlife, domestic animal and human health issues.
Biologists in DEC's Wildlife Health Program (WHP) examine sick and dead wildlife from around the state to identify a disease or determine the cause of death. WHP handles only free-ranging wildlife (not farm animals or pets), and attempts to reduce the effects of wildlife diseases on people and domestic animals. The goals are to identify and monitor infectious and non-infectious wildlife diseases, to use that information in making wildlife management decisions, and to intervene when necessary to ensure healthy wildlife populations for generations to come.
Additional testing for investigations on dead wildlife are completed at Cornell's Animal Health Diagnostic Center in Ithaca. This may include looking for bacterial infections, viruses, fungal infections, or the effects of poisoning. Cornell staff will also perform necropsies on wildlife specimens to support the WHP. DEC analytical laboratories in Gloversville and Rensselaer can test for organochlorine pesticides like DDT and anticoagulant rodenticides in wildlife.
This coyote was submitted to DEC's WHP
for examination. It was found to have an
infestation of lice.
Last year, WHP handled more than 800 cases, which ranged from tiny tadpoles to bears and moose. Most of these cases began with an observation or report from the public. Notable findings included a resurgence of West Nile virus (WNV) in birds, late winter outbreaks of salmonellosis in redpolls at bird feeders, eagles killing other eagles, several cases of rabies in deer, and multiple poisonings of red-tailed hawks with anticoagulant rodenticides in New York City.
This year we have identified winter starvation in barred owls, an unusual outbreak of salmonellosis in Long Island wading birds, more rabid deer, collisions between trains and bald eagles, mange in red foxes on Long Island, and unsolved raccoon and bird poisonings in New York City.
In addition to analyzing dead or dying animals, WHP staff participate in ongoing research projects, like examining a tumor-producing virus in wild turkeys, the prevalence of Salmonella in backyard feeder birds, and snake fungal disease.
While disease and death are part of a balanced ecosystem, stressors like the introduction of invasive species, new and emerging diseases, climate change, habitat destruction and human development can alter that balance. Through New York's surveillance program, wildlife diseases can be identified early, before they impact the wildlife population or become a danger to other animals or humans.
Dr. Krysten Schuler is a wildlife disease ecologist at Cornell's Animal Health Diagnostic Center in Ithaca.