Will Deer Truisms Hold True?

Mar 17, 2015
Survey asks hunters how weather and moonlight impact deer movements; research to test beliefs.

The moon is nearly full, will deer be moving only at night?

Is the cold front that's coming through the reason deer are out feeding?

In answering questions like these, deer hunters often rely on common wisdom. But are such truisms really true?

Well, researchers with the Pennsylvania Game Commission and in Penn State's College of Agricultural Sciences are going to find out.

But first, they are going to ask the public how they think deer respond to changes in weather and moonlight – and then test these ideas with data from movements of radio-collared deer.

"There are a lot of widely-held beliefs about what causes deer to move, how far, and when they move," said Duane Diefenbach, adjunct professor of wildlife ecology and leader of the Pennsylvania Cooperative Fish and Wildlife Research Unit at Penn State. "In our current research project, we are collecting hundreds of thousands of locations from GPS-collared white-tailed deer. We thought it would be fun to see what people think about how deer move and see if that's actually true."

Diefenbach doesn't think anyone has studied the validity of these common beliefs about how deer respond to weather and moonlight. "This is a great opportunity to find out." he added. "I'm certainly curious."

The Deer-Forest Study is a collaborative research project studying how deer, soils and vegetation interact to affect Pennsylvania forests. The Game Commission is partnering with Penn State and the state Bureau of Forestry in the efforts

The Deer-Forest Blog, where researchers share their findings with the public, is online athttp://ecosystems.psu.edu/deer. For the next several weeks anyone can answer a few questions posted there about how they think deer respond to different weather conditions, such as cold fronts, rain and wind, and how deer movements change with the moon's phases.

"We hear hunters say that deer become nocturnal following the early muzzleloader and rifle season in October," said Christopher Rosenberry, who supervises the Game Commission's Deer and Elk Section. "We now have access to technology to see if that is actually true."

Both adult male and female deer have been captured and fitted with GPS collars that transmit the deer's coordinates via satellite every three hours during October. Researchers are going to first investigate deer movements during this month because it is the archery and early muzzleloader and rifle hunting seasons, and it's before most of the breeding occurs.

"The last week of October is when the rut begins in Pennsylvania," noted Bret Wallingford, deer biologist with the Game Commission. However, compared to November, most deer still exhibit normal movements and likely are more influenced by weather conditions than breeding urges."

Anyone interested in taking the brief online survey can go tohttp://ecosystems.psu.edu/deer/, where the link will be prominently displayed.

After the survey is closed, the responses will be summarized and shared on the blog.

Two undergraduate students in the College of Agricultural Sciences, Kate Williams, a Wildlife and Fisheries Science major, and Leah Giralico, a Veterinary and Biomedical Sciences major, will be analyzing the data to see how deer actually respond to weather and other factors. In the research, they will analyze more than 13,000 deer locations for October 2013 and October 2014.