Myths And Facts About Deer Management

Increasing awareness of the overpopulation of deer in Connecticut has given rise to many misconceptions and "urban myths" about deer, their role in the spread of Lyme disease, and in the destruction of native woodlands. As a member community of the Fairfield County Municipal Deer Management Alliance, Newtown benefits from the expertise of its members and has hosted talks on the subject of Lyme disease and deer management through local organizations including the Rotary and Kevin's Community Center.

QUESTION: Isn't Lyme disease spread by white footed mice, not deer?

ANSWER: Lyme disease is caused by a bacterium that is carried by the deer tick. While it is true that the bacteria is introduced into the tick by the white footed mouse, it is the white-tailed deer that is responsible for the increasing number of deer ticks. Without deer the tick cannot reproduce as it requires a large blood meal from a white tail deer. The deer is the host of choice for the adult tick. Each deer can carry about 500 ticks. Each adult female tick can lay 3,000 eggs. Programs carried out in Maine and Connecticut show conclusively that when deer numbers are reduced sufficiently, Lyme disease is reduced dramatically. Other animals do not substitute for the deer. (Kilpatrick and LaBonte 2003)

QUESTION: Why don't we use contraception to control deer populations?

ANSWER: A $5 million experimental program funded by the New Jersey League of Municipalities has recently been dropped due to failure. The contraceptive tested, at a cost of $1,000 per doe, did not work. There is no contraceptive available.

For now and for the foreseeable future there is no tested contraceptive that actually works on wild deer. If and when it becomes available the drugs will only keep the herd from growing; they will not reduce the size of an existing herd.

QUESTION: Are there more deer-car accidents during the hunting season because hunters scare deer onto the roads?

ANSWER: No. Most deer-vehicle accidents happen after dark or before daybreak when there are no hunters out. There are more deer-vehicle accidents on Sundays (when there is no hunting at all) than Saturdays. Hunting season and the annual deer rut (mating season) coincide in late fall. During the rut, deer are energized by the mating instinct and often cross roads while pursuing does or being pursued by bucks. Also the shorter days during fall and winter mean that high traffic occurs at dawn and dusk when more deer are moving around.

No scientific data supports the claim that hunting activity increases the rate of deer-vehicle accidents. Instead, a review of data provided by the Department of Transportation supports the fact that vehicular traffic patterns influence deer vehicle accidents. Removing deer through hunting or other deer management techniques is an effective method to reduce deer populations, which will result in fewer deer-vehicle accidents.

QUESTION: If you start culling deer, is it true that the remaining deer will just start giving birth to more fawns than usual?

No, this only occurs if the deer population is so stressed by starvation that their birth rates are depressed prior to culling. Following a cull of the population, birth rates would return to normal causing population recovery. This does not apply in the case of our deer control programs since the deer populations are still healthy and increasing. Deer reproduction in our region remains a constant 1.77 fawns per doe per year according to deer biologists.

QUESTION: Which is more dangerous, hunting or Lyme disease?

ANSWER: Hunting is one of the safest outdoor activities. All hunters must pass many hours of safety instruction before they can obtain a license. There have been no nonhunter injuries in the history of controlled deer management hunts in Connecticut. There were more than 40,000 new cases of physician confirmed Lyme disease in Connecticut alone in 2002. There are also untold numbers of undiagnosed cases of Lyme that go on to develop serious cardiac, neurological, and arthritic complications. The number increases every year. There are also an average of 100 deer-vehicle accidents per town in Fairfield County each year adding to the dangers of excess deer.

QUESTION: Isn't the understory of the forest being destroyed by the canopy of mature trees and not by the deer?

ANSWER: No, the natural cycle of the forest is for mature trees to drop seeds to reseed the forest. This new growth is protected by the forest canopy from the drying sun during their early growth period. The deer, however, are selectively eating these young seedlings and wildflowers. We cannot blame this lack of understory on the "maturing forest" and "natural succession" as some would have us believe. According to forestry experts at Yale, these Fairfield County woods are not mature woodlands; they are intermediate in their development and would require at least another 50 years of growth to reach the stage of maturity that might cause loss of diversity due to dense shading of the forest floor. There is also evidence from forest and wildlife experts at the Connecticut Agriculture Experiment Station that deer are helping in the spread of invasive plants such as Japanese Barberry.

QUESTION: Is there any risk of reducing deer so low that they become endangered?

ANSWER: It is not the goal of Connecticut deer management programs to reduce the deer to critically low numbers. Further, it has become so difficult now to reduce deer numbers in Fairfield County because of lack of access to land and lack of local hunters that it may be hard to achieve adequate reduction of deer numbers, let alone go too far. Population reduction would obviously stop if numbers reached the ideal level of 10 to 12 deer per square mile. A maintenance plan would then be implemented that might include contraception if an effective one became available.

QUESTION: Why not just spray the yard for ticks or kill ticks on deer using the "4-poster device"?

ANSWER: The tick killing chemicals used are toxic to children, the environment, and water supply unless used very carefully. The 4-poster device (used to spread tick killing chemicals onto the heads of feeding deer) is at risk of spreading chronic wasting disease (CWD) through the deer herd by attracting groups of deer to feed at the corn feeder. CWD is a fatal slow virus disease similar to mad cow disease and has recently been shown (Science: October 6, 2006) to be spread through deer saliva, which is an obvious risk at communal feeding stations such as the 4-poster device. Furthermore, the deer are causing more problems than Lyme disease alone. Killing ticks will not stop destruction of the forest nor deer-vehicle accidents.

This information is provided as a service by the municipally appointed volunteer members of the 16-town Fairfield County Municipal Deer Management Alliance, which aims to promote regional approaches to the multiple problems of deer overpopulation. For more details on these topics, sources and graphs, and for more FAQs on deer management go to www.deeralliance.com.