Assateague Island Suspends Contraception Program With Hopes To Boost Horse Population

ASSATEAGUE — Following the birth of five foals on the Maryland side this year, National Park Service officials announced this week the trend could continue with none of the island’s mares slated for the contraception program in the coming year.

The popular horses on Assateague are wild animals and generally left to the whims of nature. However, in the interest of maintaining a healthy population size, the National Park Service many years ago began a contraceptive program for the mares. In almost each year since, selected mares have been darted with a non-invasive contraceptive called PZP in an effort to maintain the size of the herd on the Maryland side in its manageable threshold.

As recently as just a few years ago, the size of the wild horse population on Assateague had swelled to 140, or well north of the target range of 80 to 100. However, with some losses due to old age, illness or other man-made and natural causes, the number of horses in the herd now stands at 88, or right in the middle of the target range. Currently, there are 66 mares and 22 stallions.

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