These three mountain hares tussling in the Scottish snow may look like two males fighting over a female. Not so fast.
“I don’t see testicles, so it’s hard to judge—but usually when you see behaviour like that, it’s females rejecting the sexual advances of a male,” says Dana Krempels, a biologist at Florida’s University of Miami. “And I’m suspecting that there are two males here competing for her attention.”
It’s important to note that the male hares, or jacks, don’t usually fight each other. Jacks normally spar only with female hares, or jills. This sparring is pretty gentle compared to the more aggressive behaviour of some of their rabbit relatives.
Krempels says that the jill in the above video, which was published on YouTube last week, might be fending off the jacks because she’s not ready—hares typically mate in the spring and summer. In the fall, jacks’ testicles recede and they lose interest in mating. But their testicles can drop soon after the winter solstice, sometimes leading them to pursue a mate well before spring.
On the other hand, the jill in this video might be game for mating; she just might be testing the males to see if they’re good reproductive partners, Krempels says. (Read “5 Gross and Amazing Ways Animals Deliver Sperm.”)
“Sometimes they’re not interested, but sometimes they actually are just testing the male’s mettle and seeing how strong they are,” she says. “So it’s not always an outright rejection.”
“It’s possible if this guy kept filming, that she eventually would have made it with one of those two males, but we don’t really know that,” Krempels says.
Testing jacks is a common behaviour for jills; they can get pregnant year-round. That’s because they’re induced ovulators—that is, they start ovulating when they have sex.
Consequently, “pregnancy is pretty much assured if they mate,” Krempels says. (“I’m really, really glad humans don’t do that,” she adds.)
“Not only that, the minute [a jill] starts to go into labour, the males … immediately start hanging around and waiting for her to pop out the babies,” she adds.
“And I’m not kidding you, one minute after she has babies, they are on her again and she’s receptive and she’s pregnant again.
“It’s a brutal life.”