Birth Control Approach Tweaked With Recent Horse Deaths

Birth Control Approach Tweaked With Recent Horse Deaths
new foal naming auction with mare

ASSATEAGUE — With a survey recently completed in November, the current population of wild horses in the Maryland section of the Assateague Island National Seashore has dipped to 88 after at least four more have perished recently.

The Assateague Island Alliance (AIA), the friends group of the Assateague Island National Seashore that provides support for the famed wild horses on the barrier island, completed a population survey in November and learned the size of the herd had diminished, causing the National Parks Service to consider adjusting the ongoing contraceptive program for the mares on the island.

The November survey determined “Taffy,” the oldest mare on record on Assateague at 34, along with an unnamed mare known simply as N6G, who was 33, were classified as missing or presumed dead. In addition, another mare known as “Sarah,” or N6EH, was found on the marsh around kilometer marking 21 and was unable to get back up and was humanely euthanized. Recently, a 23-year-old stallion known as N9BQ was found dead, and in October, “Sham,” the oldest known stallion ever on Assateague had to be euthanized due to rapidly deteriorating health.

With the recent losses, the size of the herd in the Maryland section now stands at 88, or well within the ideal range of 80 to 100, causing NPS officials to readjust the complex contraceptive program administered on the wild horses on Assateague put in place several years ago to effectively manage or reduce the size of the herd. In the interest of managing the herd size, which, if left unchecked, would overtake the barrier island and gobble up the very natural resources the animals need to survive, the NPS began the contraceptive program for mares in the herd several years ago.

Selected mares are injected with a non-invasive contraceptive called PZP in an effort to prevent multiple births by the same mare as part of the effort to maintain and shrink the size of the herd to its manageable threshold. Assateague’s contraceptive program has become a model for wild horse and other animal management programs around the country.

As recently as just a few years ago, the size of the wild horse population on Assateague had swelled to around 140, or well north of the target range of 80-100. NPS officials until just recently had been in a “reduction” phase with the contraceptive program, which achieved the desired results. However, with some attrition with the oldest horses in the herd and the contraceptive program resulting in fewer births- just two new foals were added in 2014 and one this year- NPS Resource Management is moving from the reduction phase to now an “adaptive management” phase. From this point on, the results of the year-end pregnancy testing along with the estimated population will determine which, if any, mares will be darted with the contraceptive program.

Essentially, there is no way to predict how many horses will die and how many foals will be born in any given year. For example, if a large number of foals were due next year, the NPS officials would likely dart several of those pregnant mares. The contraceptive does not harm the unborn foal and will prevent the mares from becoming pregnant again.

On the other hand, if only a few foals are due next year, NPS officials would likely only dart any two-year-old mares at the time, allowing them to mature a little more before having a first foal. According to the AIA, around 12 percent of the current horse population is in their late 20s to early 30s, so the NPS will be allowing more foaling over the next few years to balance out the anticipated mortality in the older horses.

Meanwhile, the AIA is currently holding a “Name that Foal” auction for the only foal born to the Maryland herd this year. Born in mid-May, the bay pinto filly known now only as N6BMT-FM, was born to the sorrel mare “JoJo”, or N6BMS. In the 1970s, NPS officials began assigning an alpha-numeric code to new foals to trace their lineage and ancestry, and to better identify to which sub-herd they belonged and the areas they frequent on the island.

The new foal’s suspected sire is Llama Boy and the band lives in the back country of the Maryland section near the Over-Sand Vehicle (OSV) zone. Each year, the Assateague Island Alliance auctions the naming rights to a foal born in the Assateague Island National Seashore and the proceeds support the organization’s management efforts for the herd of wild horses on the barrier island.

The auction for the only foal born to the Maryland herd is currently underway on eBay. The successful bidder will earn the naming rights to the new foal, a bay pinto filly born in May. The 10-day eBay auction ends at 3 a.m. on Tuesday. As of late Thursday, the top bid for the naming rights for the new foal had topped out at $1,650 about halfway through the process.

About The Author: Shawn Soper

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Shawn Soper has been with The Dispatch since 2000. He began as a staff writer covering various local government beats and general stories. His current positions include managing editor and sports editor. Growing up in Baltimore before moving to Ocean City full time three decades ago, Soper graduated from Loch Raven High School in 1981 and from Towson University in 1985 with degrees in mass communications with a journalism concentration and history.