Human-Wildlife Conflict Management: Prevention and Problem Solving by Russell F. Reidinger Jr

Author:Russell F. Reidinger Jr.
Language: eng
Format: epub
Publisher: Johns Hopkins University Press
Published: 2022-01-15T00:00:00+00:00

Example

Assateague Island National Seashore (ASIS) is home to two herds of feral horses, one in Maryland and one in Virginia. The ancestors of today’s horses were most likely put on the island in the late 17th century by mainland horse owners to avoid fencing laws and taxation of livestock. To maintain a healthy ecosystem, the US Fish and Wildlife Service allows a grazing permit for a total population of about 150 horses. The herd in Virginia is managed by Chincoteague Volunteer Fire Company. The company holds annual pony pennings where excess ponies are sold, proceeds supporting the fire company.

The National Park Service is responsible for the Maryland horses and, to maintain their cultural and historical significance, manages the herd at a stable size. This population (fig. 11.4) has been the focus of the world’s longest running feral horse immunocontraception program. At the onset of the program, there were about 166 horses, enough to negatively impact the Assateague Island ecosystem. In 1995, Kirkpatrick and Turner (2008) began administering PZP contraceptives to all mares 2-years-old or older. The contraceptives were given using dart guns and biobullets. Subsequent treatments were based on the Park Service goals of maintaining genetic diversity of the herd (by allowing young mares to foal) and moving toward a reduced but stable population size. Conditions of the mares were monitored bimonthly by ASIS employees. Population growth was reduced to zero within 2 years, and the population size began declining in 8 years. The delay was due to improved longevity of vaccinated mares from 6.5 years to about 20 years. The increased longevity was due to improved health of the mares by reduced energy stress of pregnancy and lactation. The extent of treatment has varied depending on the population status. For example, the National Park Service suspended treatment temporarily in 2017 to facilitate an increase in herd size.

As pointed out by Hobbs and Hinds (2018), the Assateague Island situation is unique in that all mares were treated, the population was manageable, individuals were easily identifiable, the area was small, the population was isolated, and the animals were approachable by foot. Nonetheless, the program serves as an example of the potential for contraceptive technology as a management tool for free-ranging wildlife.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.