October 30, 2013
Why Deer Killing Programs don’t Solve Conflicts with Deer
No correlation between deer densities and deer conflicts
The HSUS receives calls from people all around the country who are outraged by the prospect of deer kills in their communities.
Deer kills may involve inhumane methods, result in orphaned fawns, and usually do not achieve the intended management goals.
Often, a more comprehensive approach using non-lethal methods would better achieve those same goals while teaching people to peacefully coexist with deer.
Common arguments made to support killing deer
Proponents of killing deer may argue incorrectly that killing is necessary to:
- Reduce deer overpopulation
- Protect ornamental trees, shrubs, and gardens
- Prevent deer/car collisions
- Protect parks and wooded areas from "over browsing" and biodiversity loss
- Reduce Lyme disease
Deer are highly prolific, and their high reproductive rate can quickly compensate for declines in their population. When deer numbers are reduced after killing programs, the remaining female deer will often respond to greater food abundance by giving birth to twins or triplets. Fawns also have higher survival rates and earlier onset of sexual maturity. The end result is a quick "bounce-back" in numbers.
To be successful, a killing program must not only significantly reduce the deer herd, it must sustain enough pressure to prevent this bounce-back effect, while also preventing deer from the surrounding area from wandering in. All of this usually poses an insurmountable challenge in most urban and suburban communities.
In addition, safety-mandated restrictions often limit where and how hunters can shoot. It isn't safe to hunt in most suburban areas where deer are causing conflicts, because there are too many people and too much human activity. It's no surprise that many suburban deer kills—no matter what target level is set—end up killing very few deer, after which the population quickly recovers and bounces back to its previous level.
Killing deer will not resolve people's conflicts with deer in their gardens. Certain plants like tulips and hostas are irresistible to deer. Even if the deer population could be brought to a very low level, these top-choice flowers would still be eaten by any remaining deer. That's why effective solutions focus on deterring deer and protecting flowers and ornamentals rather than trying to shoot every deer that may come along and eat them.
The key to success is for residents to understand that deer are here to stay. Once homeowners overcome their initial resistance and take steps to protect valued plants, "deer-proofing" will quickly become a normal part of life in deer country.
One of the most distressing results of human encroachment into deer habitat is the frequency of deer/auto collisions. Killing deer will not solve the underlying problem, which is that we have trapped these animals within a network of highways crisscrossing their territory and have failed to construct wildlife underpasses or overpasses that allow safe crossings.
Studies have shown that reducing the deer population does not necessarily reduce the number of collisions between cars and deer. In some cases, collision numbers are actually lower in areas with more deer. Many factors contribute to deer-vehicle collisions, such as traffic volume, speed limits, the extent to which roads bisect habits and migration routes, and the use of visual barriers. This is why reducing the number of deer alone does not work to reduce vehicle collisions with deer.
It is easy to point the finger at deer and blame them for our forest regeneration woes, yet the reality is that our ecosystem issues are fraught with complexity and subject to human aesthetic preferences which are often not grounded in any sort of biological reality.
Nature is not static. A forest floor once carpeted with wild flowers can rapidly transition into another state as a result of forest succession. Certain plant species are shaded out as trees mature and the forest canopy closes. Later succession stages are, by their very nature, less diverse.
Forest are subject to many influences that affect their growth, some less visible than others. Arbitrarily killing deer isn't likely to bring back the type of forest people may want to see.
Scientific studies and health authorities have demonstrated that killing deer won't reduce people's risk of contracting Lyme disease.
The tick that spreads the disease, the black-legged tick (or deer tick), feeds on many different hosts—almost all mammals, most songbirds, and even lizards.
Killing deer does not reduce the risk of contracting Lyme disease because deer kills do not significantly reduce the tick population. In a study from Great Island, Mass., where up to 70 percent of the deer were removed, there was no marked reduction in the tick abundance.
The black-legged tick is very adaptable. Where deer are scarce, the ticks switch to other hosts or congregate in higher numbers on the remaining deer. Deer killing programs have little effect on the tick population—and don't reduce human disease risk. Better alternatives include using products like 4-Posters and Damminix Tick Tubes to lower the tick population as well as taking proper precautions to avoid contact with ticks.
What does work?
Communities should first do objective public surveys to define and assess the nature, scope, and location of the particular deer problem so solutions can be tailored to particular sites. Then a community should develop a comprehensive plan using applicable non-lethal methods, along with setting up a robust data collection and evaluation system to monitor if deer damage mitigation strategies are achieving set goals, and adapt the programs accordingly.