The Deer Problem

BACKGROUND FACTS AND CONCEPTS

  • In the early 1900s, deer were so scarce in much of the Northeast that sightings were often reported in local newspapers.
  • Now there are more white-tailed deer than there were when Europeans first colonized our continent.
  • Each deer consumes about 1 ton of “browse” (tender shoots, twigs and leaves from trees and shrubs) a year.
  • Deer are well-suited to edge habitat, which abounds in suburbs and agricultural areas.
  • Deer can double their population in two years when foraging conditions are good.
  • Deer have evolved under intense predation and hunting pressure (from Native Americans). The high reproductive capability of present day herds likely reflects an adaptation to intense predation and hunting in the past. As a consequence, it would be inaccurate to describe a deer herd in today’s environment, with few or any predators and no hunters, as “natural.”
  • The deer population in many areas is greater than the BiologicalCarrying Capacity (BCC)- the density of deer that can be sustained by a tract of land.
  • Cultural Carrying Capacity (CCC) is the maximum number of deer that can coexist compatibly with local human populations. It’s a function of the sensitivity of local human populations to the presence of deer, and can be considerably lower than BCC. Even very low numbers of deer can exceed the CCC.
  • Hunters take no more than 15% of the overall herd each year.
  • There are ways homeowners can deal with a deer problem (fences, urine, deer-resistant plants etc.) but this doesn’t address the larger environmental issue.
  • As the problem continues to grow throughout the East Coast, more and more preserves, parks, botanic gardens and even towns are wrestling with this issue and discussing appropriate options for deer reduction in their locales.

PROBLEMS ASSOCIATED WITH LARGE DEER POPULATIONS:

Related to native plants and biodiversity

  • Damage to natural areas: create a browse line, puts pressure on already-stressed wildflowers and other native plants. For example, in the Allegheny National Forest in northwestern Pennsylvania, plant species diversity has been reduced by 67%.
  • Deer browsing changes the ecology of forests by preventing normal plant succession; eat seedling trees, preventing forest regeneration when the current mature trees are gone,
  • Forests that are over-browsed by deer are more susceptible to invasive by non-native invasive plants, which deer often don’t eat as readily.
  • Damage to home landscapes – discourages people from planting any non-deer-resistant plant.
  • Damage to nursery stock (which may or may not be native plants) E.g. PA nurseries lose an average of $20,000 a year
  • Destroys habitat for other creatures:
  • E.g. for the Karner Blue butterfly and the Baltimore checkerspot.
  • The loss of understory greatly reduces the number of insects, which are food for birds, amphibians, reptiles, and small mammals
  • Destroys the shrub layer where many birds nest. Where there are more than 20 deer/sq mile, songbird populations have declined. According to Audubon, the second-largest threat to bird habitat in PA after urban sprawl.For example, in the Allegheny National Forest in northwestern Pennsylvania some nesting birds such as the Eastern Wood Pewee have entirely disappeared from study sites.
  • According to Audubon PA - The most profound negative impact of overabundant white- tail populations is that people may alter their view and become less supportive of open space and land preservation efforts.

Other problems

  • Fatalities and injuries in addition to property damage associated with deer-car collisions
  • According to the Insurance Institute for Highway Safety there are an estimated 1.5 million deer-vehicle collisions annually in the US, causing more than 150 fatalities and $1.1 billion in property damage.
  • Deer tick-borne diseases
  • Damage to forest products – e.g. $75 million in PA alone
  • Damage to crops – e.g. $90 million in crop loss in PA alone
  • Loss to taxpayers – e.g. PA taxpayers alone lose $18 million / yr in deferred and lost timber stumpage sales.
  • Deer population can reach a point where they will starve or be malnourished by the end of winter
  • High population densities increase the incidence of diseases, such as bovine tuberculosis, in the deer themselves.

SOLUTIONS PROPOSED

From: Northeast Deer Technical Committee

Option 1: Allow nature to take its course – has led to the current problems. (Can provide lists of deer-resistant plants -though none are deer-proof if deer are hungry enough)

Option 2: Use fencing and repellents to manage conflicts with deer populations – only works temporarily and for individual properties; (Bowman’s Hills Wildflower Preserve fenced 100 acres with a 10-ft fence.)

Option 3: Use of nonlethal techniques to reduce deer - vehicle collisions - addresses only one issue

Option 4: Provide supplemental food - hasn’t been effective

Option 5: Trap and transfer excess deer to other locations – complex, expensive, liability issues, survival rates low

Option 6: Use fertility control agents to regulate deer populations - expensive and complex

Option 7: Reintroduce predators to control deer populations – not a lot of public support for the

Option 8: Control deer herds with sharpshooters - less efficient method of deer removal than controlled hunting, and it can be controversial in situations where regulated hunting could occur, because it denies citizens access to a renewable public resource. Local economies may also experience a loss of income from hunters.

Option 9: Use regulated hunting as a deer management tool. Wildlife management agencies recognize deer hunting as the most effective, practical and flexible method available for regional deer population management, and therefore rely on it as their primary management tool. Through the use of regulated hunting, biologists strive to maintain deer populations at desirable levels or to adjust them in accordance with local biological and /or social needs. They do this by manipulating the size and sex composition of the harvest through hunter bag limits and the issuance of antlerless permits, season type, season timing, season length, number of permits issued, and land-access policies.

  • Can harvest the meat for food pantries
  • Deer could be viewed as a source of green protein - more humane to hunt and eat deer who live their lives in nature and are killed quickly (and thus humanely) than to dine on fat, factory farmed animals.

RECOMMENDATIONS AND APPROACHES

NEWFS: New England Wildflower Society has formulated a plan for managing deer that includes deer fencing, deer repellants, controlled hunting and recreational hunting.

Audubon Pennsylvania recommends:

  • Restoration and maintenance of fully functional forest ecosystems, containing a full component of native biological diversity at all levels.
  • Focusing on the indicators of forest health, rather than the number of deer people are seeing, to assess whether forests are recovering.
  • Delaying restrictions on hunting through shorter seasons and smaller antlerless allocations.
  • The General Assembly, Governor's Office and the Game Commission should identify a funding base that is more stable and equitable than funding derived almost exclusively from sources such as license dollars and timber sales on game lands in order to facilitate the shift from single-species management to ecosystem management.

Some approaches by various agencies, governments etc.:

"A healthy forest can sustain deer, as well as a variety of plant and animal life, and replace its losses," pointed out Rosenberry. "So, we decided one way to gauge a forest's well-being would be to measure its ability to replace itself. In other words, are there enough young trees in a forest to replace older trees when they die, are harvested for timber, or are damaged by natural causes, such as windstorms."

"Stop thinking about numbers," says commission spokesman Jerry Feaser. "We have the right amount of deer in each unit when the habitat regenerates to healthy levels, when we have a balanced buck-to-doe ratio, when we stop hearing from hunters that there's not enough deer, and when we stop hearing from farmers and municipalities about negative deer-human contacts."

Under the guidelines of the new measures, forest habitat health would be gauged as good when at least 70% of sampled plots had adequate regeneration to replace the current forest canopy.

Last year Pound Ridge became one of the first towns in Westchester County, New York, to allow deer hunting on town-owned property. In doing so, town officials hope to address reports that five times as many deer as the environment could sustain were roaming the land.

Bull Run Regional Park (VA): In 1998 a deer density survey indicated 419 deer per square mile in the park, when 15-20 deer per square mile was the optimal number. Over-browsing was evident throughout.A program to cull select does and monitor deer herd populations was put into effect. Now, after years of monitoring and culling, spring ephemerals and other wildflowers are putting on a show for visitors again. "It's not just a one-time fix," cautions Hodnett. "It's an ongoing battle. We constantly are monitoring the deer population and culling when it begins to get out of hand."

River Bend Park:There is a conservation program with a deer-control component in place and wildflowers are abundant.

BACKLASH

Some people don’t want to reduce deer populations:

  • Hunters want to have as high a deer population as possible, so often protest efforts to reduce the population to sustainable levels.
  • People want deer in natural areas and parks. That’s what they come to see.
  • Some homeowners like the natural ambience that deer lends to their suburban landscapes.

Some people don’t want large populations, but object to killing them:

  • People generally favor only predation (though not packs of wolves or wild dogs), natural causes, or contraceptives as ways of eliminating deer. The public is often against even extending the hunting season.
  • People view hunters as wanting a chance to use a variety of weapons, not all of which kill deer humanely; just as recreation.
  • People view hunting near populated areas as unsafe.
  • There has been backlash against organizations (such as a local Audubon chapter in Calif.) that advocate killing deer even for environmental reasons.
  • When the developer of an affluent community proposed thinning the deer population by allowing bow-hunting, pro-thinning and pro-deer factions sprang up overnight, each side branding the other. It became a contest between "Barbarians" and "the Petting Zoo Crowd."
  • When the mayor of Princeton, N.J., hired sharpshooters to kill the town's burgeoning deer population, a group of protesters armed with camcorders set out to track down the gunmen.