Exotic Deer
Zoo Animals in the Wilderness
Of the four species of wild ungulates seen at Point Reyes National Seashore, only two are native to the California coastal ecosystem, tule elk and black-tailed deer. The other two species, fallow deer and axis deer, were purchased from the San Francisco Zoo in the 1940s and released by a local landowner prior to the establishment of the Seashore. Axis deer are native to India and Sri Lanka. Fallow deer, natives of the Mediterranean and Asia Minor, are the most widely introduced deer species throughout the world. Descendants of these released animals, upwards of 650 animals, can be seen throughout the pastoral lands and the wilderness areas of the park.
Hidden Impacts
Axis deer and fallow deer are known to cause detrimental impacts to native deer in other parts of the U.S. where they occur. The California coastal ecosystem has a limited supply of resources (food, water and cover) for large herbivores. Exotic deer consume some of the same vegetation as native deer and may out compete them during times of drought and low forage availability. They are also known to harbor the organism which cause paratuberculosis, a chronic, incurable disease of wild and domestic hoofstock.
A Historic Re-Introduction
In 1999, two dozen tule elk were re-introduced to the Limantour wilderness area of the Seashore. These animals are the founders of the first free-ranging elk population in the Point Reyes area since their local extirpation in the 19th century. Elk, historically the dominant herbivore in the coastal ecosystem, were hunted to near-extinction by early settlers to California. Because the new herd's range is used by both axis and fallow deer, Seashore managers are concerned that competition for forage, risks of disease transmission and direct behavioral interference may all impact the long-term survival of the elk population.
Expanding Threats
Since 1994 when control of exotic deer populations was discontinued, numbers of both species have returned to pre-controlled levels, approximately 250 axis deer and over 475 fallow deer. Axis deer populations, in particular, can increase very rapidly because of year-round breeding and early sexual maturity in fawns. Fallow deer, once limited to the central portion of the Seashore, are now found throughout all wilderness areas. Fallow deer range has even expanded beyond the borders of the park into nearby private property and state parklands.
The National Park Service and Exotic Ungulates
NPS policy on non-native animals requires their control or elimination when they pose a significant threat to park values, i.e. when the species: "threaten to alter natural ecosystems; seriously restrict, prey on, or compete with native populations..." (National Park Service, 1991). A 1999 Presidential Executive Order mandated that each Federal agency: "...detect and respond rapidly to and control populations of (invasive species) in a cost-effective and environmentally sound manner..." Point Reyes National Seashore is currently drafting a management plan for exotic deer that will address the need to restore viable populations of native ungulates to the coastal ecosystem. Monitoring of exotic deer numbers and range will continue.