More deer are killed on Pennsylvania highways than most other states take during the regular hunting season. About 45,000 deer are reported killed on the keystone state highways every year, but this is probably only a fraction of the actual number of deer/auto collisions. Many deer run off to die in the woods or live the rest of their lives crippled in some manner. One insurance firm reported processing over 50 claims a day during the month of November. This is during the period of the rut when deer are less cautious about crossing highways.
Erie Insurance Company says the average deer/auto collision claim cost is about $2000. This included 2533 deer/auto collisions reported in 2001 that required the car to be towed. Auto body shops are the only business enterprises benefiting from an out of balance deer herd.
Deer carcasses left on the highway are hazards to safe driving and hazards to health during the warm season. Removal of dead deer is expensive. Someone must be hired to do the job. Gasoline is consumed picking up the deer and driving it to a landfill or a pit excavated on gamelands. Some 35,000 deer carcasses were removed last year at an average cost of about $100 per deer. That's three and a half million dollars and the reason why the Game Commission allows people to pick up a deer they've hit to take home and butcher. Since this is normally illegal, you are required to call the Game Commission first to get permission.
Some measures have been taken to reduce the number of deer/auto collisions. These take the form of signs, reflectors, vegetation control, deer underpasses, and electronic alert systems. The latter costs $100,000 to install and consists of a flashing sign alerting drivers that a large animal has passed an electronic eye and is crossing the road ahead of them. Reflectors direct headlight beams into the woods alerting deer to passing traffic. Underpasses consist of high fencing that guide deer to a tunnel beneath the highway. Slides of two interesting signs were shown at the Deer Conference in Harrisburg. One read, "Adopt a Dead Deer Control Area." Another read "Aggressive Deer High Crash Area." They got our attention.
Auto insurance costs are not the only liability of an abundant deer herd. Pennsylvania has a 4-billion dollar forestry industry, but few of the trees are regenerating because of over-browsing by deer. The forestry service spends 10 million a year or more on deer fencing to keep the animals out of clearcuts so the trees can regenerate. The difference in the vegetation on the inside and outside of these fences is astonishing. Many foresters say without the fencing, tree regeneration in many areas would be nil.
The Department of Agriculture estimates the average annual deer damage to Pennsylvania farmers is $9,000. Remember that agriculture is still the number 1 industry in the state.
There are no figures available, but damage to landscaping shrubs and trees in suburban areas is also significant.
When you add up the costs from insurance, forestry and farming the liability of an over abundant deer herd runs into millions, perhaps billions of dollars - negating much of the money gained in the state from sport hunting.
Ecological damage is much harder to put a dollar sign on. There is ecological damage beyond the inability of the forest to regenerate trees. What is the value of the birds, mammals and insects that are deprived of the forest understory cover? Whip-poor-wills decreased as the deer herd increased. I don't know if deer were the main cause of the whip-poor-will decline or not. Correlation by itself does not prove cause and effect, but whip-poor-wills feed exclusively on nocturnal insects, particularly moths whose caterpillar stages are tree defoliators. Ovenbirds and at least a dozen other ground-nesting songbirds are deprived of nesting cover because of deer herbivory.
McShea and Schwede reporting in the Journal of Mammalogy in 1993, found that high populations of deer in a localized area were capable of removing a huge percentage of the total acorn crop in a short span of time. Such efficient removal may limit other wildlife populations in years of low acorn production such as turkey, ruffed grouse, squirrels and white-footed mice.
When trees are blown down by the wind, they are not replaced in deer over-browsed forests. More air currents can circulate through the woods removing bark from trees thus reducing the habitat of bark dwelling invertebrates and the thereby the food of woodpeckers.
Wildflowers disappear along with their pollinating insects. Lyme disease spread and increased as the deer population grew. Unfortunately, reducing the deer population will probably not reduce Lyme disease risk. Once the bacterium is in the area it can be carried by ticks on deer mice, which are everywhere. In general, biodiversity drops dramatically where deer get out of balance with the carrying capacity. Placing dollar signs on all these accumulating ecological effects is next to impossible.
The suburbs present a special problem since the only deer predators are dogs and cars, combined with a sympathetic public that does not understand that natural controls must be replaced with artificial controls. The next essay will look at how Fox Chapel and Murrysville are addressing the deer problem.
