Originally, when I applied for a position to trap deer this winter, I thought that I would be working on the other half of the Deer-Forest Study. If you recall, I spent two seasons sampling herbs and woody species as a Forest Field Technician. The supervisor for the deer and elk section had other plans for me, however. During my job offer, he asked if I was interested in working on the Chronic Wasting Disease (CWD) study in South Central Pennsylvania. He added that I would make a good fit to the crew that he was assembling. I still don’t know what that means but I could not pass the opportunity to assist a new study. After all, wildlife disease is fascinating! I accepted a position on the Blair County CWD deer trapping crew. That is why I am here in Martinsburg this winter.
Let’s begin with some background.
Chronic Wasting Disease was first discovered in Colorado in 1967. Although in small numbers, it has been found in captive and free-ranging white-tail deer in Pennsylvania since 2012. CWD is a contagious and progressive disease that always results in death. It affects cervids — deer and elk. The disease is caused by a prion, an abnormal form of a protein that is commonly found in the central nervous system. In the infected animal, prions are concentrated in the brain, nervous system, and lymphoid tissues. The disease causes brain cell death that results in microscopic holes in brain tissue. A year may pass before an animal exhibits symptoms of infection. Symptoms of CWD are shared with other wildlife diseases and include: extreme weight loss, excessive drinking, urination, salivation, and behavioral and neurological changes. Infected animals often lose their fear of humans and predators. CWD is transmitted both directly (animal to animal) and indirectly (food and soil) primarily through bodily secretions. It can also be spread by contaminated carcasses and high risk animal parts. The prions can remain viable in soil for many decades and is closely related to Mad Cow Disease in cattle and Scrapie in sheep and goats. At this time, there is no evidence than CWD can be transmitted to humans or traditional cattle. However, the consumption of infected meat is not advised. There is no known cure for CWD.
Long story short, the CWD study evolved from the initial detection of the disease and the agency’s mission “to manage Pennsylvania’s wild birds, wild mammals, and their habitats for current and future generations.” A protocol is in place to survey, manage, and respond to wildlife disease. Under this direction, the CWD study was created to collect information needed to make management decisions.
Along with my crew, my role in the study is to trap deer this winter. Our activities take place on both state game lands and private property of cooperative land owners. First, we bait suitable areas to attract deer. Once we understand the deer activity, we use drop nets to capture the animals. Certain deer are fitted with a GPS/telemetry collar that will allow individuals to be tracked. Reward tags are attached to each ear in an inconspicuous manner to identify the individual and persuade hunters to report the harvest. Hunters who call into the number printed on the tags receive a monetary reward in exchange for information on the deer.
We are doing this for several reasons. Among those, we are hoping to get information on: survival and harvest rates, a population estimates, dispersal of yearlings, home ranges, and habitat use. By collecting this data, biologists will gain a better understanding of the impact and spread of CWD. Hopefully, this information will be used to make informed management decisions of Pennsylvania’s white-tailed deer.