Drastic Deer Damage Requires Drastic Deer Reduction

"Deer now completely inhibit the establishment of new shoots... As shrubs die, alien invasive plants explode in density, gaining a strong foothold even under intact forest canopy."
"It is clear that the only way to give our forests a chance to recover from both overbrowsing by deer and alien plant invasions is... a drastic reduction in the deer herd (about 5 per square mile for a drastically damaged forest to begin to recover)." "No field research needs to be done before initiating drastic deer herd reduction. Until native plants are regenerating in abundance, there is absolutely no reason to undertake the expensive task of counting deer." Emile DeVito
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"Overabundant deer populations also negatively impact native plant communities and landscape plantings in residential areas. Because deer can eat 5-10 pounds of forage per day, overabundant deer herds can eliminate native plant species and change the structure and diversity of plant communities. Changes in the structure and diversity of plant communities affect the diversity and abundance of other wildlife species, such as small mammals and birds. Deer densities that exceed 20 deer per square mile can significantly impact ground and shrub nesting birds and change composition and abundance of plant species within forest ecosystems." (From CT DEP Booklet, page 4)

"Forests can heal themselves when they have a population of 5 to 10 deer per square mile, “but now 35 per square mile is common, it’s well over 50 in some places, and in a few places in New Jersey it can be 250 or even more,” Dr. DeVito said. “One overabundant species is sacrificing thousands of other species. We have to recognize that, and deal with it.”  Click here for Full Story.

The environmental evidence that over 10 deer per sq mile is destroying woodlands:

Loss of native tree species: Evidence from the Connecticut Agriculture Experiment Station (Departments of Forestry and Horticulture): "Overabundant deer herds can eliminate native plant species and this can adversely affect other wildlife such as small mammals and birds that nest in shrubs and on the ground. Deer are impacting oak, sugar maple, pine and cedar forests in many parts of Connecticut, preventing regeneration of young saplings."  “Managing the deer population is essential to maintaining the health of these preserves,” said Lise Hanners, Ph. D., state director of The Nature Conservancy in Connecticut.  “At high numbers we know that deer restrict the growth of new trees, shrubs and flowers.  Without some sort of management, the quality of the forests at these preserves will continue to suffer.”  

Loss of wildflower species: Nature Conservancy and Ct. Ag. Experiment Station studies reveal loss of the following wildflowers in areas with over 10 to 12 deer per square mile: trout lilies, red trillium, lady slipper orchids and Canada lilies.

Loss of bird species: Connecticut Audubon's 2007 State of the Birds report lists the following birds as reduced or endangered by excessively deer-browsed forests with over 10 deer per square mile: Wood thrush, hooded and other warblers, house wrens, song sparrows, eastern towhee, indigo buntings, yellow breasted chats and golden winged warblers.

CT Audubon State of the Birds Report 2007

Yellow-breasted Chat (CT Endangered) Golden-winged Warbler (CT Threatened)

Milan Bull, Senior Director of Science and Conservation of Connecticut Audobon, provided the following testimony on March 10 2008 to the Environment Committee of the Connecticut General Assembly is support of House Bill 5852: An Act To Control Lyme Disease:

"With the understory stripped by deer, shrubland birds are unable to find suitable nesting habitat and are severely impacted. Bird species such as Golden-winged Warbler, Brown Thrasher and Yellow-breasted Chat, currently listed as Threatened or Endangered in Connecticut are a few of our songbirds that are impacted by deer over browsing. Over browsed forests have also reduced the populations of Wood Thrush, Hooded Warbler, Eastern Wood Pewee and Eastern Towhee and many other species."

"Bluff Point Coastal Reserve in Groton, Connecticut, serves as a good example of how overabundant deer herds can impact plant communities. In 1975, the Connecticut General Assembly designated Bluff Point as a Coastal Reserve to protect its unique plant and animal communities for the benefit of present and future generations. Deer hunting was not permitted at Bluff Point. In the late 1980s, the DEP documented severe deer overbrowsing of vegetation, and in the mid-1990s, surveys estimated the deer population exceeded 200 deer per square mile. Deer exclosures (8-foot high fenced areas) were constructed in 1990 to visually document the impacts of overabundant deer populations on the plant ecosystem. After 5 years of no deer management (1995), vegetation outside the exclosure remained un- changed, while vegetation structure and diversity within the deer exclosure increased dramatically. In January 1996, a deer reduction program was initiated at Bluff Point. During the following 5-year period (1996-2001), the deer population was reduced from about 222 to 20 deer per square mile. The reduced deer population resulted in a significant increase in vegetation structure and diversity outside the deer exclosure.

In residential areas, overabundant deer herds can impact flower and vegetable gardens and defoliate landscape plantings. Some homeowners who enjoy observing deer occasionally feed deer during winter. Deer also will take advantage of bird feeders in residential areas as a source of food during winter.(33) Supplemental feed may enhance deer productivity and artificially congregate deer into small areas, which increases damage to natural vegetation(16) and the potential of bringing ticks into residential areas." (From CT DEP Booklet, page 5)

Nature Deficit Disorder

Fear of ticks keeps kids indoors in many northeastern states. Connecticut has the "No Child Left Inside" program to help get kids back outside, however nothing has been done to make the outdoors any less risky for kids exposed to Lyme infected ticks in their own backyards.

Nature Deficit Disorder: A National Concern
Environmentalists worry that the loss of contact with the natural world will weaken Americans' commitments to conservation and biodiversity.

By Froma Harrop
Published on 2/13/2008




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