What do you do if you want more sex but your partner is about to leave? How about scaring her.
The male topi antelope keeps his mate around by snorting deceptively, a pretense that makes her think leaving him will bring her face-to-face with danger, scientists now reveal.
"It's like the folk tale, only the male topi cries 'Lion!' rather than 'Wolf!' " explained researcher Jakob Bro-Jørgensen, a behavioral ecologist at the University of Liverpool in England.
Bro-Jørgensen and behavioral ecologist Wiline Pangle at Michigan State University have been studying the topi (Damaliscus lunatus) in Kenya's Masai Mara National Reserve since 1998. When spying a lion, cheetah, leopard or other predator, both male and female topi typically give off a snort and gaze at the carnivore with ears pricked. This usually discourages stalkers from approaching close enough to launch a successful attack, as they are unable to outrun the antelopes over longer distances. (Watch the antelope in action.)
"A topi alarm snort might have saved me once by alerting me to two lionesses who had sneaked right up to my open car window while I was absorbed in observing the topi," Bro-Jørgensen recalled.
Each mature female is usually only sexually receptive for one day every year some time during the month-and-a-half-long mating season. On the day of ovulation, on average these females visit 10 male territories and have sex 11 times.
The researchers found that when a female who is in heat gets ready to leave a male's territory, the male often makes a false alarm call while looking intently where the female is headed at an imaginary predator in the distance. Rather than risking any danger ahead, the female typically lingers a while longer, giving the male more chances at sex.
"The lie is so blatant that it is quite amusing," Bro-Jørgensen told LiveScience.
Deceptive males typically copulated about another three times in the stint between snorting deceptively and the eventual departure of the females. In 10 percent of visits with false snorts, the male succeeded in mating only after he had begun snorting,
When playing back both true and false alarms from loudspeakers mounted on car windows and hidden from the antelopes, the researchers found that female topi were unable to distinguish between the two calls. In both cases, the females looked around for a predator and took a few steps back.
"In fact, males quite frequently pull the trick on females in heat and one may ask why females keep responding to alarms at all," Bro-Jørgensen said. "The answer seems to be that females are better off erring on the side of caution, because failing to react to a true alarm could easily mean death in a place like the Masai Mara, where it's literally crawling with large predators."
Although this kind of sexual deception might seem familiar to humans — say, when a man points out something spooky to get her to hold on more tightly — it has never been documented in other animals before, the researchers said.
A wide variety of deceptions are seen in the animal kingdom when it comes to sex — for instance, chimpanzees use false alarms to distract rivals and get close to mates, while male swallows use false alarms to disrupt their mates' adulterous liaisons.
"The study shows that animals may have higher cognitive abilities than we often think," Bro-Jørgensen said. "It highlights that much still remains to be uncovered about the complexity of animal minds."
Bro-Jørgensen and Wiline Pangle will detail their findings in the July issue of The American Naturalist.
