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Newsletter announcing elephant pregnancy, 2000
In 1991, Smithsonian Conservation Biology Institute physiologist Dr. Janine Brown made a discovery that improved how we breed elephants. Most mammals have one surge of a specific hormone, called a luteinizing hormone, that triggers the release of an egg for fertilization. But Brown showed that elephants have two surges of the hormone, about three weeks apart, before ovulation. The National Zoo adjusted the timing of its breeding efforts, which enabled Shanthi (pictured with Dr. Brown) to become pregnant in 2000. |