Female giraffes have a great Valentine’s Day gift for potential mates: urine.
A special anatomy helps male giraffes understand whether a female is ready to mate, reported January 19 in the journal Animals animal behaviorists Lynette and Benjamin Hart. Researchers have found that the pheromone detection organ in giraffes has a stronger connection with the mouth than the nose. This is why males choose which female to mate with by sticking their tongue into the stream of urine.
Animals such as male gazelles lick fresh urine on the ground to track if females are ready to mate. But giraffes’ long necks and heavy heads make bending down to examine urine on the ground an unstable and vulnerable position, says Lynette Hart of the University of California, Davis.
Researchers observed giraffes ( Giraffa giraffa angolensis ) in Etosha National Park in Namibia in 1994, 2002 and 2004. Bull giraffes pushed or shoved a female to ask her to urinate. If she was a willing participant, she peed for a few seconds while the male took a sip. The male then curls his lip and inhales through his mouth, a behavior called the flamenco response, to draw the female’s scent into the two holes in the roof of his mouth. From the mouth, the odor travels to the vomeronasal organ, or VNO, which detects pheromones.
The Garths say they have never seen a giraffe explore urine on the ground.
Unlike many other mammals, giraffes have a stronger oral connection — through a duct — with the VNO than the nasal one, examinations of preserved giraffe specimens have shown. One possible explanation for this difference could be that the VNO-nose connection helps animals that breed at certain times of the year to detect seasonal plants, says Benjamin Hart, a veterinarian also at the University of California, Davis. But giraffes can mate at any time of the year, so the nose connection may not matter much.
