White tail migration and mortality
What researchers have learned so far about studying white-tailed deer.
While these studies are ongoing and it will be a while before they have a more complete picture of white-tailed deer ecology, researchers have already gained insights. For example, in 2019, researchers ran a pilot study in units 15 and 10A using the same GPS technology — doe collars, implants for pregnant does, and fawn collars — as they did this year. The pilot study provided valuable new information on white-tailed deer movements in 10A, which helped researchers refine their capture efforts in 2020 to better represent the overall white-tailed deer population in 10A.
“Especially in Unit 10A, we learned that there are some deer that are migratory, and some that are not,” Roberts said. “We changed our capture strategy this year to make sure our trap sites were in different levels of human interface. We have deer that are habituated to human interaction in Unit 10A. This year, we made sure the clover traps were spread out more to try to sample the entire variety of whitetails.”
“We captured deer in some areas where we thought animals would migrate more than they did. Most ended up on private land, which influences survival and vulnerability,” Hurley added. “This year will be the first year where we have a really good, unbiased dataset where we’ll be able to see how well those animals survive into the fall.”
Over the course of the pilot study, the GPS collars also gave researchers a glimpse into what percentage of newborn fawns typically survive, and what the most common causes of mortality are.
“What we’ve seen so far is that we’re usually losing half or more of them before they’re a year old, and most of the mortality is from bears or mountain lions — primarily bears,” Hurley said. “That’s kind of an interesting result, in that it’s a little different than what we see down in mule deer country.”
Although researchers are currently focusing a lot of their attention on white-tailed deer, the work they are doing with whitetails is the centerpiece of a holistic multi-species study. The goal is to understand how all populations of large predators and prey interact, and how best to manage each species within the framework of the larger picture.
