Deer
 White-tailed deer are commonly observed on roadsides, crossing the
firebreaks, and feeding on lawns and recreation fields. Due to the
relatively poor browse, the average body size of the deer in central Long
Island is generally smaller than that in other portions of New York. In the
spring of 1994 most does had twins, but one doe was observed with three
fawns. The diversity in habitat (lawns, mowed roadsides, open fields) as
well as protection from hunting has probably resulted in a greater density
of deer on the BNL site than would be expected in an unaltered Pine Barrens
habitat.
White-tailed Deer (Odocoileus virginianus)
White-tailed
deer typically have a home range of 2-3 square miles, depending on the
quality of the habitat (DeGraaf & Rudis, 1983). Preferred habitat consists
of forest edges, swamp borders, and areas interspersed with fields and
woodland openings. Young (one to two fawns) are typically produced in May
and June. Deer are adaptable in their food habits, feeding on grasses,
herbs, and aquatic plants in summer and buds, twigs, and some conifers in
winter. Deer have heavily browsed yew bushes, particularly those in the tree
plantations.
Causes of mortality for white-tailed deer on the site include roadkill,
domestic dogs, and illegal hunting. Several deer skeletons have been found
on the site with multiple broken bones indicative of automobile collisions.
In the past a doe with a healed, but previously broken, leg was observed on
several occasions near the sewage treatment plant. BNL employees have
related that domestic dogs from nearby developments often pursue and kill
deer on site. One deer skeleton with a broadhead (arrow point) embedded in
the shoulder blade was found in 1993 (several tree stands [hunting
platforms] were observed along the east property line and near Half Moon
Pond); and a pile of internal organs was found east of the east firebreak in
October 1994. It is unknown whether the deer was killed on-site or the
organs were from a deer taken elsewhere. Deer are periodically harvested by
BNL as part of ongoing environmental monitoring.
Concentration of Cesium-137 (Cs-137) in Deer Meat are monitored
Based on data collected since 1992, analysis of meat from white-tailed
deer (Odocoileus virginianus)
- Samples collected onsite have shown concentrations of Cs-137 that are
above background (1992-1997 Annual Site Environmental Reports). A recent
evaluation by NYSDEC Wildlife Branch and the NYS Department of Health
(NYSDOH)
concluded that the level of Cs-137 in meat does not pose a risk to human
health when such meat is consumed (Bureau of Environmental Radiation
Protection, NYSDOH March 1999). (Note: Hunting has never been allowed at the
BNL site, for security reasons. Although deer have a limited
range--approximately one mile, according to the NYSDEC—some do move
off-site).
- The NYSDOH study also concluded that the elevated levels should not impact deer
health.
- Monitoring of soil, vegetation, and deer meat from onsite locations over the
past several years indicates that the Cs-137 concentration levels have been
decreasing. This decrease is expected to continue with time due to natural
radioactive decay, as no new Cs-137 is being added to the environment from
BNL operations.
- Contaminated areas have been addressed, soil removed and disposed of, under the Environmental Restoration Program.
Population densities of deer are also monitored
The deer population onsite was estimated in 1992 (Thomlinson and Naidu) and
indicated the population exceeded 700. Since then, the onsite population has
apparently increased, in part probably due to land clearing in areas
adjacent to BNL. In 2000, the deer population reached an estimated high of
1000 individuals. The population declined quickly until 2003 where the
population soared again to 1000 individuals. Recently, the population has
been declining to the current estimate of 400 individuals in the spring of
2007. The change in population was most likely caused by lack of food
available and varies with the severity of the winter.
Since 2000, surveys have been completed twice a year, once in the spring
and once in the fall. An aerial infrared survey was conducted in 2004,
revealing the population to be around 450 deer. As a result of the aerial
survey, a new model was developed to estimate the population using the
Laboratory's vegetation map in the Geographic Information Systems (GIS).
This method accounts for the uneven distribution deer onsite due to habitat
differences.
Population Management
BNL also has programs to manage the
deer population to ensure that they are sustainable. BNL is in the process
of evaluating options for controlling deer populations onsite. Normally a
population density of 10 to 30 per square mile is considered an optimum
sustainable level for a given area. However, since the BNL site has a
population density between 80 and 200 per square mile, the need to initiate
population control at the BNL site must be considered. Overpopulation
affects animal health, results in increased property damage and traffic
accidents, as animals forage into developed areas for food. A number of
options are being evaluated for feasibility and effectiveness. All options
require a thorough evaluation prior to implementation, and community
involvement would be planned if measures such as population culling and hunting were
recommended.
References:
1.
December 1994; Sitewide Biological Inventory, Phase II.
2.
Naidu, J.R.; Brookhaven National Laboratory Wildlife Management Plan,
September 22, 1999.
Note: Text citation may be found in the above reference documents.
Last Modified: February 1, 2008
Please forward all questions about this site to:
Mary Daum
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