Are there too many deer?
Deer herds throughout the eastern United States were heavily exploited after the arrival of Europeans around 1600. In the early 1900's, deer populations began to increase due to a lack of predators and an increased availability of food and habitat. When Catoctin Mountain Park was established in 1936, much of the land was considered sub-marginal. The forest was decimated due to the removal of trees for charcoal and lumber, and the white-tailed deer was few and far between. The protection that national park status brought to the land and the early efforts of the Civilian Conservation Corps to plant trees in the new park at a time when deer numbers were low allowed for a healthy forest to grow. As the forest grew healthier, food became more plentiful and the deer found refuge in the park since hunting was, and is, prohibited by law.
The forest of Catoctin Mountain Park has that become strained under the demands of a large deer herd, which eat nearly all of the young trees. Other wildlife species such as turkeys and squirrels are also affected as they compete for limited food.
Deer Management Plan
Catoctin Mountain Park developed a Deer Management Plan/Environmental Impact Statement (EIS) that supports forest regeneration and provides for long-term protection, conservation, and restoration of native species and cultural landscapes. The selected alternative in the EIS calls for continuing current park deer and vegetation monitoring and research. In addition, it includes using qualified federal employees to conduct lethal removal to reduce the deer population to the initial goal of 15-20 deer per square mile. This goal is based on recent research conducted in eastern deciduous forests similar to Catoctin's forest. The park held three public meetings from 2004-2007 to gather comments on alternatives that were being considered and the draft plan. The final EIS was signed by the NPS National Capital Regional Director in April 2009.
Deer Management Begins
Park staff implemented the first season of deer management operations in February 2010. Extensive safety measures were put in place to protect park visitors and neighbors during the operations. Operations were conducted mostly at night, when the park was closed to visitors. During daytime operations, roads and trails were intermittently closed and clearly marked and bait was used to attract deer to safe shooting locations.
Park managers worked with highly trained biologists from the Wildlife Services branch of the United States Department of Agriculture, Animal and Plant Health Inspection Service. This agency has a long history of conducting safe and effective actions to reduce wildlife populations, including the reduction of deer populations at multiple locations in the region. Since 2009, more than 36,000 pounds of venison from Catoctin have been donated to local nonprofits to serve those in need.
The deer density goal (15 –20 deer per square mile) set forth in the deer management plan/EIS was achieved in 2016 after seven seasons of reductions. Catoctin Mountain Park's deer population was roughly 123 deer per square mile in the fall of 2009, before the first season of deer management.
After seven years of deer management, there has been a 10-fold increase in tree seedling density in the park, which demonstrates that deer management can be an effective tool in promoting seedling regeneration. Other native plants have benefited from the smaller number of deer. For example, the state threatened purple-fringed orchid was more plentiful in a 2016 census than it was in 2008, and the downy rattlesnake plantain orchid was more than ten times as plentiful as it was in 2008. Park staff began using fencing in the late 1980's to protect the purple fringed orchids from disappearing. Fencing is no longer needed today.