City survey shows deer population increase despite cull

Tuesday, February 23, 2016 - 3:44pm

According to the city’s latest annual aerial survey, Ann Arbor’s deer population has grown by 20.2 percent over the past year. This increase comes as the city’s deer cull, which aimed to reduce the population by 100 dear, moves into its final weeks.

The results of the survey showed 202 deer were counted by a 3-person team from a helicopter — an increase from the 168 deer reported in March 2015. However,  Ann Arbor Communications Director Lisa Wondrash noted that flyover surveys are not to meant to serve as a comprehensive census.

“(Flyovers) give insight into the minimum deer population in certain areas of the city at one point in time,” Wondrash wrote in a press release. “Deer count numbers are useful as data points that can track trends over time.”

Wondrash also wrote the city’s deer cull is ongoing, with 51 deer already killed by marksmen from the United States Department of Agriculture since early January, and that 1,050 pounds of venison from the culled deer has been distributed to a local food bank.  The cull is expected to kill 100 deer and is slated to end on March 1 this year.

Christopher Dick,  a professor of ecology at the University of Michigan and public supporter of the cull, wrote in an e-mail interview that aerial counts typically need to be doubled to arrive at an accurate population and making the actual Ann Arbor deer population is at least 400.

Dick also wrote that a combination of sampling error and exponential population growth likely contributed to the increased despite the ongoing cull.

“Many of those 168 deer (counted last year) were pregnant and gave birth, and there is low mortality in urban deer populations; deer grow exponentially and we really could be seeing a population explosion,” Dick wrote.

Ann Arbor resident Bernie Banet, a member of Washtenaw Citizens for Ecological Balance — a local advocacy group supporting the cull — pointed to the latest count as evidence that a more comprehensive deer management strategy needs to be undertaken.

“We’re not surprised at all that that the population (of deer) is larger now,” Banet said, adding that his group had originally advocated for an annual cull target of 300 deer and estimated the local population of deer could be as high as 1,000. As further evidence that the Ann Arbor deer population is still growing, Banet noted that the number of deer-vehicle crashes in Ann Arbor had increased from 51 to 88 in from 2014 to 2015.

Because that number is much larger than what has been proposed in the last few years, Banet acknowledged there was no reliable method to verify this.

“We always thought 100 (deer to be culled) was low, and now it looks like we aren’t going to approach the total,” Banet said.  

When asked if he felt the latest count was evidence that the cull should be expanded, Banet replied that further analysis should be done.

“It’s a sign that serious discussion has to be made and one thing to consider is whether the size of the cull this should be larger,” Banet added.