Deer Overabundance

Deer Overabundance Hudson Valley

White-tailed deer (Odocoileus virginianus) are an important component of our forests. However, a lack of natural predators and the ability to thrive in man-made suburban habitats have caused deer populations to outstrip their natural food supply over the last few decades. Forest ecosystems can generally sustain native plant regeneration as long as deer densities remain under 4 deer per square kilometer [1]. Unfortunately, deer population densities have reached over 27 deer per square kilometer in many areas of the region. Under these conditions, tree seedlings that would typically replace older and dying trees are rarely able to grow to maturity. The impact can be severe- some forest ecosystems subject to deer overbrowse may not recover the ability to regenerate for at least forty years [2]. Forests serve as habitat for birds, mammals, insects, and all kinds of other wildlife, and deer overbrowse poses a threat to all of these animals.

When deer herbivory creates light gaps in the forest, it makes it easy for invasive plants like the light-seeking oriental bittersweet to recruit and outcompete native species. Deer overabundance can also have adverse effects on local economies. Farmers in New York have reported significant profit losses due to deer browse specifically. Deer may play a role in the spread of Lyme disease-bearing ticks. In New York, vehicle collisions with deer may account for as many as 70,000 accidents per year [3].

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