Minutes of Ridgefield Deer Committee Meeting
October 25, 2004
Copper Beech Room
Ridgefield Rec. Center, Danbury Road
Pat Sesto, Co-Chair
Tom Belote, Co-Chair
Peter L. Keeler
The Committee heard two speakers, Howard Kilpatrick, Senior Biologist Connecticut Department of Environmental Protection, and Georgina Scholl M.D., Assistant Chairman of the Fairfield County Municipal Deer Alliance.
Mr. Kilpatrick presented and narrated a slide show entitled “Deer and Deer Management in Connecticut”. Mr. Kilpatrick began his presentation noting that White tailed deer are herbivores that consume between 5-10 lbs. of vegetation each day. The life span of a white tailed deer is 18 years and, on average, a healthy adult doe produces 2 fawns annually. The deer population can double in size every 2-3 years. Based on aerial surveys the deer population in Connecticut has quadrupled since 1974 and was estimated to be approximately 150,000 in 2001. A DEP study showed that Fairfield County and the shoreline areas of New Haven County New London Counties demonstrated an increasing deer population between 1996 and 2001. The rest of the state had a stable deer population and two northern DEP zones, 1 and 4, had a decreasing population Mr. Kilpatrick described the white tail deer as prolific breeders who benefited from the “fragmentation and edge areas” in Fairfield County. The deer are not only extremely adaptable but also benefit from the improved habitat created by vegetation in the edge areas that are created by suburban development. Mr. Kilpatrick stated that the relative absence of predation and the beneficial habitat created by fragmentation was a significant impediment to controlling the deer population particularly in areas like Ridgefield and the rest of DEP Zone 11. Mr. Kilpatrick advised that hunters were the only serious predator and that coyotes or other animals posed no serious predation to the deer.
To demonstrate the impact of the deer population on the habitat Mr. Kilpatrick presented slides showing a controlled exclosure, an area in an open field area that had been fenced-in in 1990 to prevent deer from consuming the vegetation within. After five years the fenced-in area showed heavy vegetation compared to the unprotected surrounding area where the deer continued to consume and destroy vegetation. After ten years the growth in the exclosure was extremely dense and high while the unprotected area surrounding the experimental station continued to be devoured by deer. Mr. Kilpatrick said that the deer had impacted upon the environment casing a loss in plant and animal bio-diversity. As an example he presented the study conducted by McShea & Rappole (2000) in which an exclosure was used to study the impact of the deer population on songbird habitat. In that study the population of ovenbirds was shown to be significantly higher in the protected exclosure compared to the unprotected control area.
Mr. Kilpatrick presented figures on the public safety impact of the overpopulation of the deer including deer/vehicle accidents and the increase in Lyme disease. Ridgefield ranked #1 in the number of deer/vehicle accidents in the state with a Department of Transportation rated of 89 per year. Because of under-reporting and the fact that DOT records only reflect the collisions on state roads and those incidents where the dead or injured deer are located on the roads, the DEP believes the actual rate to be significantly higher than that reflected in the DOT records. Consequently, the DEP believes the actual number of deer/vehicle accidents to be 5 times higher than the number reflected in the DOT reports. Mr. Kilpatrick discussed the white tail deer’s role in the increased rate of Lyme disease in our area and critical role as a host to the mature tick.
Mr. Kilpatrick estimated that the deer population in Ridgefield was in the 100+ deer per square mile range and could be as much as 120 deer per square mile. He advised that he did not know exactly what the “carrying capacity”, the maximum sustainable population based on a square mile of land, for white tailed deer would be in Ridgefield but he believed Ridgefield is far from “capping out” and advised that the deer population will continue to grow in town. Mr. Kilpatrick advised that a population of less than 20 deer per square mile was required for forestation and a population of 10-15 was desired to protect herbaceous cover.
Mr. Kilpatrick said that deer management options included: 1) do nothing; 2) use fencing and repellents but that that option was only practicable for small enclosed areas; 3) relocation which is no longer a viable option because no other state or area would accept the deer and that studies have demonstrated that over 50 % of relocated deer die of injuries sustained in the process; 4) fertility control which is not practicable in a free ranging environment such as Ridgefield; 5) hunting which is the principal management tool used on free ranging herds; 6) sharp-shooting which is new to Connecticut. Connecticut adopted sharp-shooting regulations this year. The sharp-shooting regulations are outside the normal hunting regulations and required special permitting from the DEP. Only municipalities, not-for-profit organizations and landowner associations can apply for sharp-shooting permits.
Following Mr. Kilpatrick’s presentation the committee heard from Dr. Georgina Scholl, Assistant Chairman of the Fairfield County Municipal Deer Management Alliance. Dr. Scholl has been in charge of the Fairfield County group’s investigation into deer contraception and an alternative deer management methodology. Dr. Scholl advised that deer management through contraception remains experimental. Advances in delivery systems, coupled with improvement in the efficacy of anti-fertility agents, may improve the prospect for limited applications of deer contraception in the future but the cost of manpower and materials, and the practicality of treating and adequate number of deer, will likely limit the use of immunocontraceptives to small insular herds. Managing free ranging white-tailed deer populations over large landscapes present problems not found with more isolated herds. Dr. Scholl advised that deer contraception experts believe that isolated populations, such as those found on islands or in large fenced-in areas, have the greatest potential for success. Unless contraception agents can be developed that work through the animal’s digestive system and can be added to foods, the cost of administering the contraceptive agent to each female deer is prohibitively costly. Because fertility control has no short-term effect on population size, pre-treatment culling would be an essential part of the timely resolution of deer problems with fertility control. Research on birth control is ongoing but the United States Food and Drug Administration have approved no contraceptive vaccine for wildlife. FDA approval is necessary as there is the potential for any drug used on wildlife to get into the food chain and our food supply. To date this type of contraceptive agent is non-species specific and therefore can effect other wildlife species other than the white-tailed deer for which it is targeted. Contraception is a reversible process therefore any program of contraception must continue indefinitely. It is estimated that 90% of the doe population would have to be treated to control the deer population. Existing estimates for the cost of administering contraception range from $1,100 per deer and higher.
The meeting was adjourned at 8:40 P.M.
The next nesting was scheduled for November 9, 2004 in the Copper Beach Room of the Red Center.
On December 14, 2004 a speaker from the Fund For Animals will address the committee.