Local in Ann Arbor

The last three years have been the Early Period for Ann Arbor’s deer debate.  Now there is a coherent plan for deer management and a page containing historical documents on the Ann Arbor City website – quite a long story.  We posted extensively about this issue through 2015. 2017 will be busy. In a special session on November 14, 2016, Council approved several resolutions to make the management plan operable.   According to the Ann Arbor News, officials are still awaiting permit approvals by the Michigan Department of Natural Resources (DNR).  Maps showing where a sterilization program will be conducted have also been published.

For several decades, the white-tailed deer have been appearing around the edges of the city. But as of early 2014, they became numerous enough to be real pests.  As the numbers of the animals began to intrude on more and more human lives, there was an organized effort to limit their effects on gardens, natural area vegetation and automobile crash incidents.  Their impact on parks and natural areas in Washtenaw County was recognized by the WC Parks & Recreation Commission in early 2014. In May 2014, Ann Arbor’s City Council directed the City Administrator to prepare a report on deer management in partnership with other entities.

Numbers of DVCs in Ann Arbor City between 2005 and 2015. Source: Michigan Traffic Crash Facts.

As the account in the Ann Arbor Chronicle about that Council meeting indicates, one impetus to raising the problem of the increasing deer population was the slow increase in the number of deer-vehicle crash incidents.  These are reported in Michigan via a website, “Michigan Traffic Crash Facts“, whose data is from safety (law enforcement) personnel.  (There is always a delay after the end of a calendar year in publishing the totals for the previous year, so as of today’s writing we must wait for a couple of months before we know the totals for 2016.)  By 2014, DVCs in Ann Arbor had increased by 30% from the previous decade.  Last year, there was a major jump in numbers of crashes.  We’ll be watching to see if 2016’s number indicates a trend or that this was an aberration.

A single doe and her offspring over 5 years. Males are not shown.

So why do we need a deer management program?  Because of their explosive reproductive capability.  As we explained in detail in our post, Deer and the Numbers Explosion, deer will increase their numbers exponentially if left unchecked.  In the early years, one only notices that there are more deer around than in the past.  Suddenly 10 deer are camping out in your backyard.  This increase in numbers has many effects on the immediate territory.

The common white trillium is used as an indicator of deer herbivory. Photo by B. Ball, courtesy of the UM Herbarium.

1. Plant herbivory: Most plants (or at least their edible parts) are consumed.  This causes damage to gardens and landscapes, and natural areas where native plant communities are being maintained are severely altered. As we explained in Deer and the Flowers of the Earth, wildflowers are beautiful and a source of delight for visitors, but they are also extremely important in the survival of the entire wild community.   Plants are “foundational” in a wild ecosystem and without them, nothing lives, even the deer.  Fifth Ward councilmember Chuck Warpehoski has expressed this beautifully in his recently updated post.
2. Deer-vehicle crashes: As we have already noted, DVCs increase with increasing population.  To date, we have not had any crashes locally where a human has been killed, but there has been considerable dollar damage to automobiles and the potential for human injury is certainly there.
3. Lyme Disease:  Deer have a complex relationship with this disease.  They provide a blood meal for black-legged ticks, the vector for this bacterial disease, and help carry the tick into new territory.  Also, their plant herbivory often favors an understory full of Japanese barberry.  Deer don’t eat this thorny shrub and it provides an ideal habitat for the white-footed mouse, the main host for the tick.  Mice multiply under the canopy of the low shrub and help carry the tick and its bacterial rider into new territory.

Lyme disease is known as an “emerging disease” in Michigan.  It has been moving into new areas of the state. When the deer problem was first highlighted in 2014, it was thought to be a couple of counties west of Washtenaw.  Now there are recognized cases in our county.  We are all at risk.   I hope that our governments provide adequate education so that people can recognize the disease and seek immediate treatment.   Here is a good place to start.

UPDATE:   The City of Ann Arbor has now posted an explanation of the 2017 deer management program.  A somewhat more easily accessed account was published by MLive. 

Here is the deer management map.  Note that some residential areas are targeted for participation in the nonlethal program. Also note that without fanfare, some UM properties have been included in the lethal culling program.

SECOND UPDATE: The University of Michigan made some of its properties available for the cull for the first time this year, eliciting some cries of anguish from the opposition.  Here is an explanation from the University Record of the program from the UM perspective.

THIRD UPDATE: On March 8, 2017, there will be a lecture program addressing the problem of deer herbivory from an experimental and data-oriented viewpoint. The two presenters are both experienced with direct testing of deer-wild flora interactions.  Jacqueline Courteau is a wildlife biologist and consultant, and Paul Muelle has been the manager of natural resources at a major park (Huron-Clinton Metroparks) through a time that culling and vegetation assessment have been practiced to maintain the parks’ resources.  Here is the full announcement about the talk.  It will be at the Matthei Botanical Gardens, 6:45 p.m. on March 8.

This entry was posted on December 30, 2016 at 5:15 pm and is filed under Neighborhoods, politics, Sustainability. You can subscribe via RSS 2.0 feed to this post's comments. You can comment below, or link to this permanent URL from your own site.