Great Expectations
Elephant researchers believe they can boost captive-animal reproduction rates and reverse a potential population crash in zoos.
- By Kara Platoni
- Smithsonian magazine, June 2003, Subscribe
(Page 3 of 6)
For years, some zoos have facilitated elephant courtship by loading a female onto a truck, driving her to a breeding bull and hoping for the best. The hope was usually forlorn. Infertility is a problem. Females older than 30 who are conceiving for the first time have a high incidence of stillbirths, and about 15 percent of captive Asian females and 25 percent of captive Africans of calf-bearing age are known as flatliners, meaning their reproductive hormone cycle is inactive.
Artificial insemination, which has worked well on many other species, is a challenge with captive elephants. Designing a means of navigating an elephant’s eight-foot-long, curving reproductive tract and timing an elephant’s estrus are among the obstacles. (An elephant’s period of fertility—only two or three days out of every four-month estrus cycle—has been difficult to predict until recently.) In addition, facilities without a resident male must import bull sperm, which remains potent for only 24 to 48 hours. (Elephant sperm usually loses its viability when frozen, so establishing a sperm bank is not an option.) At the National Zoo, which doesn’t have a bull, veterinarians must obtain samples from several bulls at different locations across North America and must time inseminations precisely. “It’s like cooking a huge meal,” says Brown, adding, “It takes a lot of planning to make sure that all the different courses come out at the right time and it’s all hot when you go to serve it.”
In October 1995, the National Zoo attempted its first artificial insemination on an Asian elephant named Shanthi, using new technology designed by Berlin’s Institute for Zoo Biology and Wildlife Research. Along endoscope, which was equipped with fiber optics and contained a catheter that was guided by ultrasound, successfully delivered sperm. But Zoo scientists missed the elephant’s estrus by four days. In reviewing Shanthi’s case, however, Brown discovered a hormone that spikes three weeks before a female becomes fertile. This finding now allows researchers to pinpoint estrus with a simple blood test.
The first successful birth following artificial insemination took place in November 1999 at the Dickerson Park Zoo in Springfield, Missouri, when Moola, an Asian elephant, gave birth to a male named Haji. (He died from the herpes virus two and a half years later.) In 2001, Shanthi became the second artificially inseminated captive Asian elephant to deliver a calf. Despite the technical challenges and costs, ranging between $10,000 and $15,000 per event, artificial insemination offers the best way of increasing the birthrate in the short run, says Dennis Schmitt, an animal science professor at SouthwestMissouriStateUniversity, who, along with Brown, is one of the nation’s foremost experts on the procedure. “It’s not the answer, but a tool,” he says.
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