Since 2000, HSI and The Humane Society of the United States have been working with scientists to develop a non-hormonal birth control method—called “immunocontraception”— to control breeding in confined wild animal populations. So far, the method has been used to successfully control populations of deer and horses in North America, as well as African elephants in South Africa.

In many parts of the world, free-ranging large, wild mammals are, unfortunately, a thing of the past. Instead, humans have confined many populations to large areas—such as reserves—with fences or other barriers. If allowed to breed normally, these confined populations tend to eventually outgrow their designated land. The inability to migrate elsewhere can lead to competition for resources, environmental degradation, and loss of biodiversity. To prevent this, managers are faced with reducing the population through culling, translocation or other means. Such reactive methods are often cruel and do not address the root cause of the problem—animals will reproduce.

HSI continues to fund life-saving, cutting-edge research into immunocontraception as a humane alternative.