From the Field

Connecting YOU with Wildlife – Pennsylvania Game Commission


No. 1 – What is Chronic Wasting Disease?

Through the end of deer season, we will be posting a frequently asked question (FAQ) and answer related to chronic wasting disease (CWD) in Pennsylvania in an album on our Facebook page.

We know many of you – hunters, non-hunters, processors, taxidermists and more – have questions about CWD and the effects this disease can cause. We are here as a resource and want to help everyone understand the complexities and details related to CWD in our state.

If you have a specific question related to CWD, email pgccomments@pa.gov.

Here’s the question for week one:

CWD Fact 1

Answer:

Chronic wasting disease (CWD) is an always-fatal neurodegenerative disease of cervids including deer and elk. CWD is a type of Transmissible Spongiform Encephalopathy disease, other TSE diseases include mad cow disease, scrapie, and Cruetzfeldt-Jakob disease.

The causative agent of TSE diseases is an abnormally folded protein or prion. As these prions accumulate in the brain, they begin to cause tissue damage, eventually leading to holes in the brain.

CWD can be transmitted directly (through animal-to-animal contact) or indirectly (through a contaminated environment). CWD prions can be shed through bodily fluids such as saliva, urine, and feces. CWD was first detected in 1967 in a captive deer facility in Colorado. Since then, CWD has spread to 25 states and three Canadian provinces, including Pennsylvania.

Click here for more information.

As a reminder, if you have a specific question related to CWD email it to pgccomments@pa.gov.

 

Advertisements


Who’s Their Daddy?

FawnTwins.Dingel

Game Commission Photo: Jacob Dingel

Do only top-ranking bucks breed does?

For decades, people believed the white-tailed deer mating system was a dominance-based breeding hierarchy. In other words, most offspring were sired by a few dominant males. For white-tailed deer, this meant – or at least we presumed – the top-ranking buck (based on physical traits like age, body mass, and antler size) had breeding rights to any and all females he encountered. No questions asked.

Behavioral observations set the stage for this theory of the whitetail mating system. But what happens when we aren’t watching? Thanks to genetic technology, we now realize that we only read the first chapter on white-tailed deer breeding ecology.

Multiple Paternity in White-tailed Deer

In 2002, the next chapter was revealed. That’s when an article in the Journal of Mammalogy was published titled “Multiple Paternity in White-tailed Deer Revealed by DNA Microsatellites.” This paper documented multiple paternity in captive white-tailed deer. In litters of two or more fawns, 26 percent of them had different fathers.

This discovery raised the bigger question: does multiple paternity – and female promiscuity – occur in wild, free-ranging deer populations? The answer came two years later. In 2004, the first case of multiple paternity in free-ranging white-tailed deer was documented in Michigan (Journal of Mammalogy, “Paternity Assignment for White-tailed Deer: Mating Across Age Classes and Multiple Paternity”). Here, 22 percent of litters with two or more fawns had different fathers.

This research also showed the oldest males did not monopolize breeding; thus, shattering the belief that a few dominant males do all breeding. Since this initial finding, multiple paternity has been documented in every free-ranging white-tailed deer population that has been tested.

Twenty to twenty-five percent of all those twins out there are only that in the most basic sense of the word- two offspring produced from a single pregnancy.

Twins.Dingel

Game Commission Photo: Jacob Dingel

Interesting Fawn Data

Most does birth two fawns in the spring. Triplets have been documented but are far less common.

From past embryo counts in Pennsylvania:

Two-year-old does: 34% carried a single embryo, 64% carried twins, and 3% carried triplets

Adult does (> 3 years old): 22% carried a single embryo, 73% carried twins, and 5% carried triplets.

By: J.T. Fleegle

Wildlife Biologist, Deer & Elk Management Section

Pennsylvania Game Commission