SIDNEY, Maine — On a recent Monday morning, Keel Kemper got into his state-issued pickup truck and prepared to embark on a November ritual shared by him and other wildlife biologists who work for the Maine Department of Inland Fisheries and Wildlife.
Over the course of a few hours, he visited local butchers and gathered data on the deer they had hanging in their shops. The goal: Provide as much data as possible, which will be used to craft future deer management strategies.
Among the most important pieces of data are antler beam diameters and average weights of yearling bucks, which help biologists decide if the available habitat is adequately supporting the number of deer on the landscape.
State deer biologist Kyle Ravana calls these regular trips to local meat cutters “meat locker” visits.
Kemper loves this time of year, during which he’s often on the road, canvassing shops across some of the state’s most productive deer territory. But he said his daughter has another way of describing the often gory work he does.
“This is a special time for [wildlife biologists]. We don’t take vacations in November, because it’s deer season,” Kemper said. “We go out, and as my daughter says, ‘Check those yucky heads.’ It’s fun. I’ve known these [meat cutters] for a long time now.”
Checking those “yucky heads” isn’t for everybody. But Ravana and Kemper are among those who consider this seasonal chore essential to their mission.
“Deer science is rocket science. It’s that complicated,” Kemper said. “That’s why you have to have someone like [Ravana], who is bright, and works with it all the time.”
In November, providing Ravana the data he’ll crunch the rest of the year is job No. 1.
And you can only gather that data one “yucky head” at a time.
“What kind of data?” you may ask.
You might be surprised.
Science on the hoof
When Kemper arrived at his first stop — G & G Custom Deer Cutting in Winslow — co-owner Joseph “Rocky” Gravel was ready for him.
Tucked off to the side of a deer that was hanging from a meat hook were an assortment of, well, yucky heads. Each had been saved for Kemper to check.
Attached to one antler was a tag with some vital information written on it. From that tag, Kemper was able to determine where the deer was shot, when the hunter filled the tag, and the identity of the hunter.
On a clipboard, he itemized the data as he went. Weight. Points on the antlers. Age class.
Across the state, biologists gather similar information at meat lockers, aiming to sample 15 percent of the deer harvested each year, according to Ravana. But the DIF&W regularly surpass that goal.
“Across the season, we end up getting 25 to 30 percent of the harvest,” Ravana said. “So we’re sampling 4,000 to 6,000 deer a year. We’re actually getting our hands on these animals and measuring physical characteristics to help us identify how our population is doing. And that information that we collect goes directly into helping with the decision process when it comes to [any-deer] allocations each year.”
Some of those deer are found on house-by-house visits after a biologist checks the tagging records at a local station, and a few other methods. The bulk of those animals are checked at meat lockers.
Kemper said that when he’s checking animals, there are really only three kinds of deer in terms of the data gathered.
“For our purposes here, they’re either a fawn, a yearling or an adult,” Kemper said.
And believe it or not, the yearlings are the most valuable of all.
“Big, wall-hanging rocking-chair bucks are nice, but I’m not going after those,” Kemper said. “But I’ll drive a long way for a little yearling, an 18-month-old deer.”
Yearlings are important for a pretty simple reason, Kemper said.
“The deer has only been through one winter,” he said. “The more winters they go through, the more [statistical] noise it becomes. So what you’re going to see is a reflection of the previous winter in that yearling crop.”
Simply put: If you look at thousands of deer that have only been alive through one winter, the average condition of that age class can be attributed to things that have taken place over a very short period of time. After a deer’s been alive for eight years, for instance, it’s more difficult to pinpoint habitat or overpopulation concerns by making simple measurements and collecting data.
“You’re going to see some other things as well,” Kemper said. “For example, if you’re nearing carrying capacity, [the maximum number of animals that the habitat can support], you’ll begin to see smaller racks.”
Ravana said that biologists record the antler beam diameter from a spot an inch above the antler’s burr. Comparing the averages of those measurements over time, and in different parts of the state, can help indicate the herd’s health.
“A yearling deer’s main concern is to put on body mass. That’s going to allow them to be successful in terms of breeding,” Ravana said. “If they are healthy and there’s a lot of forage on the landscape, they not only have enough to meet their energetic demands and put a lot of growth into their muscle mass, they’ve also got a lot of extra energy to put into the growth of their antlers.”
And the opposite is true: If the average antler beam diameter is lower than expected, it can indicate that there’s not enough food available for the number of deer in a particular area.
Biologists also take a tooth from each adult deer — those older than 1½ years — and send it away to a lab. The tooth is then cut, and the deer’s age can be determined by counting rings, just like you’d do with a tree.
Yearlings are more simple: Kemper opened the mouth of one of the deer in Winslow and pointed out that it still had some of its baby teeth — a clear indication that the deer was a yearling.
A similarly sized deer in the Winslow shop had adult teeth that were stained; that tooth was sent to the lab.
Ravana said the various data points that are collected help form a more complete picture of the state’s deer herd.
“[Recording antler points, antler beam diameter and dressed weight of an animal] allows us to look at the health of the population,” Ravana said. “If antler points are decreasing on average, over time, there’s something going on. The deer are probably nutritionally stressed, and they’re not able to grow antlers like they were previously. It’s the same thing with antler beam diameters.”
And in some areas where commercial deer farms are nearby, biologists take a lymph node sample, which is later tested for chronic wasting disease. No cases of the deadly disease have been found in Maine, but Kemper said biologists remain vigilant in their testing, which they suspect is more likely to show up on deer farms than through transmission from native deer on the landscape.
“If it gets here, it’s not going to be good,” Kemper said.