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August 31, 2010

HSI Announces New Elephant Immunocontraceptive Method

HSI/The HSUS announce proven new method to control the rate of reproduction in African elephants

Humane Society International

Humane Society International and The Humane Society of the United States are announcing the results of a 10-year research project that demonstrates that contraception can be used to humanely and effectively control reproduction in African elephants in small to medium private game reserves. HSI/The HSUS have been funding the research in the Makalali Game Reserve for 10 years, as well as the vaccine production in veterinarian Henk Bertschinger’s laboratory at the University of Pretoria for the last seven years.

The contraceptive method provides reserve managers with a proven alternative to culling or other inhumane or invasive procedures. The findings, obtained from a field project supported by HSI/The HSUS since 2000 at the Makalali Conservancy in South Africa, will be announced at a symposium on Compassionate Conservation: Animal Welfare in Conservation Practice, to be held in Oxford, England, Sept. 2-3.

“We are delighted with the results of our research which demonstrate that it is possible to control small to medium-sized African elephant populations through immunocontraception,” said Bertschinger, one of the project’s leaders. “The method, which is reversible and has minimal side effects at the injection site, is already very popular for the contraception of wild elephants in small to medium-sized game reserves in South Africa. Failure to control the reproduction of this species in reserves like this soon leads to a population that exceeds the carrying capacity of the reserve and to habitat degradation.”

Immunocontraception is a birth control method that uses the body’s immune response to prevent fertilisation and thus pregnancy. Further information on this approach is available here. The method does not require capture of the animals for treatment. It is a non-hormonal method that is safe within the food chain and poses no environmental threats. The vaccine is delivered by a dart fired from a vehicle or a helicopter. Treated cows develop antibodies that prevent sperm from penetrating and thus fertilizing the egg. To develop sufficient antibodies cows need to be vaccinated three times during the first year of treatment and to maintain the effect an annual booster is given. Reversal is achieved by stopping vaccination of individual cows.

“Remotely delivered wildlife contraception has already proved to be humane and cost-effective (when one considers all the costs) for ungulates in the United States and we are confident it will become the method of choice for small and large elephant populations in Africa and Asia,” said Andrew Rowan, Ph.D. and CEO of HSI. 

Research is under way to produce a “one-shot” vaccine that will mean that females will only have to be darted once during the first year and then every alternate year. This will reduce cost by at least half, increase the practicality and allow the treatment of much larger numbers of elephant cows in any one area.


Humane Society International and its partner organizations together constitute one of the world's largest animal protection organizations — backed by 11 million people. For nearly 20 years, HSI has been fighting for the protection of all animals through advocacy, education, and hands-on programs. Celebrating animals and confronting cruelty worldwide — On the Web at hsi.org.

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The Humane Society of the United States is the nation's largest animal protection organization — backed by 11 million Americans, or one of every 28. For more than a half-century, The HSUS has been fighting for the protection of all animals through advocacy, education and hands-on programs. Celebrating animals and confronting cruelty — On the Web at humanesociety.org.

Follow The HSUS on Twitter

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