Asian bull elephants: Flehmen-like responses to extractable components in female elephant estrous urine.

Flehmen-like responses (urine tests) are one of the characteristic behavioral reactions of male Asian elephants (Elephants maximus) to cow elephants in estrus. Components of the urine of estrous cow elephants were extracted with organic solvents and partially purified by chromatography and shown to evoke Flehmen-like responses when they were presented to adult bulls.