Oh Deer, We’ve Got a Problem

“There are so many deer in my neighborhood because they have nowhere else to go.” This is a very common misconception. Duke Farms, The NJ Conservation Foundation, and others recently held a webinar where they presented nineteen years of deer management data. Although the data was specific for their study area at Duke Farms in Somerset County, NJ, it can be applied to most of Northern NJ and the East Coast. Their data proves what most of us know. There are too many deer.

It is obvious that our ecosystem is not balanced. When you look through a local forest, such as The Hilltop or Eagle Rock Reservation, you can see through the trees. This is a sign of an unhealthy ecosystem. The deer eat everything they can reach. No young trees are left to replace old ones. The destruction of the forest understory threatens the habitat of other wildlife. In a concept known as The Cascade Effect, when the deer population increases, the tree diversity decreases, then the caterpillar population decreases, and finally the bird population then decreases. Since new trees are not allowed to grow, invasive species are left behind and flourish, causing more havoc to an already stressed ecosystem. Further exacerbating the problem, homeowners and developers also plant invasive or non native species that result in a “food desert” for local wildlife. 

Controlling runoff and filtering water are a few of the many reasons why trees are known as effective agents of stormwater management. Without their natural replacement, the resulting runoff from overgrazing will increase.

Besides the economic loss to farm crops and homeowner gardens, deer carry ticks which cause Lyme Disease. Car collisions from deer are another negative result of overpopulation.

In Northern New Jersey, white tailed deer have no more natural predators. They have easy access to food. Building more homes and creating yards actually increases feeding opportunities for deer, as they are known as an edge species. This means that they thrive in areas where forests meet fields. A typical neighborhood in Verona is a perfect example of an edge habitat. Building more homes, such as in the developments on Fairview Avenue and The Hilltop, actually increases the feeding opportunities for deer.

These are some of the highlights from the Duke Farms (about 11 sq km) study:

•  In 1900 deer locally extirpated (gone)
• 1972 there were 4 deer/sq km (3-5 deer/sq km is recommended)
• 2004 there were 80 deer/sq km
• A heavy culling was done, then maintenance over 15 years
• 2019 about 15 deer/sq km
• 225 deer shot in 1 sq mi in 3 evenings in 2004

 Verona is 2.815 sq. mi = 7.29 sq km. Verona should have approximately 30 deer if we go by 4 deer/sq km. 

 Duke Farms was able to put up a fence (exclosure) as a study area. Data shows that native species increased dramatically inside the fenced area after deer culling. It even increased OUTSIDE the fence.  Invasive plants will get shaded out and die from lack of sun when native seedlings are allowed to grow after deer are shot.

In an urban area, the focus should be on deer removal as a public health/safety concern due to vehicle damage and lyme disease. At Duke Farms, aggressive hunting and exclosures were the MOST important tools. How to accomplish population control in densely populated areas such as Verona is still a conundrum. If deer are removed from one area and not in another, they will soon move into the empty area. This is what makes the deer population control issue so complex.

 What can we do in Verona in the meantime? Avoid supplemental feeding of deer with commercially bought food such as cracked corn which causes deer to congregate into unnaturally high densities. Choose to plant native species. Fence areas where possible. Protect young native saplings. Remove any invasive species growing on your property. Even at 30-40 deer/ sq km, the return of less preferred native species is possible. Let’s make our yards naturally balanced “Food Destinations” for all wildlife!