Study: Mortality Rate High for WI Big-Woods Fawns
Only 2 out of every 10 newborn whitetails will survive a year in northern Wisconsin, if one year of research...
Only 2 out of every 10 newborn whitetails will survive a year in northern Wisconsin, if one year of research done by Badger State scientists proves a trend. DNR researchers captured and radio-collared 30 fawns in the spring of 2011; by April of this year only 6 were still alive.
Predation was the leading cause of mortality, accounting for 15 dead fawns (bears killed 5, “unknown predators” took another five, bobcats nailed 4 fawns, coyotes got one, and “unidentified canid” took another). Hunters, poachers, vehicle collisions and another “unknown” rounded out the list.
This 80% fawn mortality rate is only the beginning of data the WDNR is gleaning from a multi-year mortality study. In the winter of 2010, researchers began capturing adult deer in two study areas; one located in the heavily-forested northern part of the state, the other in central Wisconsin, where agriculture is more prevalent. Fawns were captured and collared beginning in the spring of 2011. According to the Milwaukee Journal-Sentinel, the $2 million study is being funded by the Federal Aid in Wildlife Restoration Fund.
The tough life of a north woods fawn stands in contrast to those collared in the central Wisconsin study area, where 27 of 48 fawns collared in 2011 had survived to this spring, for a survival rate of 56%. There, a fawn was as likely to be killed by a vehicle (six deaths) as eaten by a predator (six deaths, four attributed to coyotes). Natural causes accounted for the rest of fawn mortality sources.
WDNR researchers are also examining mortality factors for adult deer, and I look forward to seeing more data on that as it’s accumulated. I also applaud the agency for taking on this study. It will not only provide much-needed information, but it has also involved citizen input and cooperation. I know two landowners who have allowed deer to be captured on their land in the central study area, and another pair of young women who assisted researchers with fawn captures in the north woods this spring. Wisconsin residents love their whitetails, and it’s great to see the DNR engaging them in this important research project.