Grad Student Researches Deer Predators
Cody Norton, an NMU graduate student in biology, still has the elementary school journal in which he first expressed his desire to become a DNR officer. The Marquette native and avid outdoorsman knew he wanted to work with wildlife. He gained a preview of his dream career by participating in an Upper Peninsula study on how predators impact the survival of white-tailed deer, particularly vulnerable fawns in the spring/summer, and how predation is influenced by other factors such as winter weather and habitat food supply/cover. All of this is critical to proper deer herd management.
“Coyotes kill more adult does and fawns than wolves, bear or bobcats,” Norton said. “That may be surprising to most people in the U.P., but when you break it down, it makes sense. An individual wolf is capable of eating more deer than an individual coyote, but there are way more coyotes on the landscape. This makes them account for the greatest mortality of deer. Bear are the second-largest killer of fawns and wolves are second for adult does. It’s awesome to be part of this because it’s the largest study of its kind and I wouldn’t have been able to complete it on my own. The findings will be used to help guide policy decisions and supply a basis for further research.”
The 12-year study by Mississippi State University and the Michigan DNR is being conducted over three phases in U.P. snowfall zones ranging from low to high: Escanaba, Crystal Falls and Ontonagon. It includes wildlife population estimates, vegetation surveys and a winter severity index based on snowfall, wind speed and. Norton helped to “live capture” deer and predators and equip them with GPS collars that monitor their whereabouts and behavior.
“When we live trap carnivores, we put on collars that record their location more frequently—every 15 minutes,” Norton said. “That’s huge so we can find clusters of animals, go where they’ve spent time and figure out what they were doing there. We may find predation sites with dead deer and have to determine whether the animal killed it or was scavenging an earlier kill. We might find other prey sources like snowshoe hare and ruffed grouse. With bear, it might be evidence of vegetation they’ve eaten. Even though the focus is on deer survival, we’re getting to look at carnivore resource use, which is really cool. The GPS aspect has been the most fun and the biggest component of the study.”
According to the study’s website, white-tailed deer provide food, sport, income and viewing opportunities to U.P. residents and visitors. The index of deer abundance in the Upper Peninsula has steadily declined since 1990, while predator abundance has increased. But in some areas, deer overabundance results in damage to farm crops, deer-vehicle accidents, and suppression of forest vegetation. For these reasons, it is important to monitor the deer population and understand the reasons why it fluctuates in either direction.
Norton’s thesis focuses on black bears, specifically the effects of the timber harvest and infanticide risk on their population. He won the Truman Award for best poster presentation at the International Conference on Bear Research and Management in Thessaloniki, Greece. He also presented at the Wildlife Society national conference in Pittsburgh. He will complete his thesis over the summer before graduating in August.
On April 27, Norton will officially fulfill the childhood wish expressed in his elementary school journal. That is the day he begins his new job as the Shingleton wildlife biologist with the Michigan DNR. The position may limit his involvement in the deer-predator study, but he said there should be many opportunities to incorporate his research findings into the management of wildlife populations in the Shingleton area.