Monitoring Deer Impacts on Natural Vegetation in Ann Arbor:
A Pilot Study of Red Oak Seedlings as Experimental Indicators of Deer Browse Intensity
Across 10 city parks
November 2015 – October 2016
Jacqueline Courteau, Ph.D.
Consulting Biologist/Ecologist, NatureWrite LLC
October 17, 2016
This pilot experimental study, in which red oak seedlings were planted and monitored in 10 city parks (and in a separate study at the Arboretum), found that deer are browsing 20–90% of tree seedlings, a level that exceeds the 15% recommended in existing scientific literature as allowing for sustainable tree regeneration (Blossey 2014). Overall, deer alone were responsible for 76% of the browse-damaged seedlings, with an additional 11% browsed by both deer and small mammals.
A total of 9% of seedlings were browsed by small mammals only; including seedlings also browsed by deer, 20% of seedlings showed evidence ofsmall mammal browse.