As deer season begins across the Northeast, regulars stopping by their country store for a cup of coffee, the daily newspaper, and the latest local gossip may also notice wildlife biologists collecting data from hunters and the deer they bring in. These “check stations” are important to state fish and wildlife departments’ efforts to measure deer population numbers and overall health.
“The main thing we’re looking at is maintaining a healthy population that is in sync with the habitat,” said David Sausville, wildlife management program manager for the Vermont Fish & Wildlife Department.
To do that, biologists gather a variety of data. This includes a deer’s weight, sex, and age. For the latter, biologists give an initial estimate, based on the number of teeth and how worn they are. They also remove a front incisor from each harvested deer, which is sent to a lab and cross-sectioned to determine a more exact age – a process Sausville likens to counting the rings on a tree.
For antlered bucks, biologists also note the number of points on each rack, the inside spread of the antlers, and the beam diameter – measured one inch above the base of the antler. If that beam diameter is more than 16.5 millimeters, Sausville said, it indicates the animal was able to glean the nutrition it needed to remain healthy, which suggests the deer population is in balance with the food available in its habitat.
“The physical condition metrics we obtain at reporting stations provide a more objective measure of whether deer numbers have exceeded what the habitat can support,” said Nick Fortin, Deer & Moose Project leader for Vermont. “When there are too many deer, body weight and antler size will be lower.”
The Department’s objectives include managing for the number of deer that biologists believe is sustainable and maintaining minimum physical condition thresholds. Wildlife biologists note that the data collected varies from year to year, but provide an overall picture of the health of the state’s deer herd – and help to inform long-term management decisions.
“These population estimates are calculated every year, but because of the complex nature of estimating wildlife population metrics, and also because most wildlife management decisions are based on trends and not on any one number in a particular year, we tend to focus on trends over time,” said Katherina Gieder, biometrician and research manager for Vermont Fish & Wildlife. “We compare yearly [measurements] to standardized measurements within a certain range for similar geographic regions, and we compare these across Vermont, with different WMUs (Wildlife Management Units) having slightly different standards we measure against depending on the amount and quality of available habitat and winter severity.”
Check stations are located throughout the state, most often at general stores and outdoor sporting retailers. Collecting data from deer in the 21 WMUs throughout Vermont provides a broader picture of how deer are faring in various habitats and weather conditions. While hunters are required to register the animals they harvest throughout the season, biologists are typically present at the stations only during opening weekend of the regular season (this year, November 12 and 13) and youth weekend (October 22 and 23).
Attendants at the stores where check stations are located will also help with collecting and recording data when biologists are not able to be there. “It’s a type of citizen science,” Sausville said. “Hunters like to have their animals looked at. They’re giving us data that we wouldn’t be able to go out and collect on our own. All of this data helps inform the models that we develop to estimate the deer population and health in the state.”
That population is now around 130,000 deer, said Fortin. He noted the deer population has fluctuated historically, but has been relatively stable for the past 15 years. The Department sets population objectives for each WMU – rather than for the entire state – and Fortin said the majority of the WMUs “have populations close to their respective objectives.” A handful, mainly in the Champlain Valley, will likely be “above objective” in 2022, meaning these areas have a higher deer population than the habitat can support in the long term.
The Department also collaborates with the University of Vermont and other colleges to collect and analyze genetic samples, which can indicate whether there are distinct populations separated from others. And biologists collect blood samples to look for various parasites and diseases – including the Covid-19 virus.
Beyond data collection, Sausville notes the biological check stations are culturally important, too. “These stations become an epicenter for some of these towns. People like to see the animals coming in, and they like to have conversations with us. It can become kind of a family event, especially on Youth Weekend, when you have the siblings and cousins and grandparents. Everybody’s excited, and they’re celebrating,” he said. “Sometimes people who are not hunters will come up and ask questions, and it’s good for them to know what we’re doing.”