The running of the quolls
Little mammals need speed for marathon mate-finding sessions
By Susan Milius
Male Northern quolls live fast and die young in a romantic frenzy of long-distance travel. And that’s only part of the reason why animal athletics specialist Robbie Wilson of the University of Queensland in Australia chases quolls with a plastic block.
Boldly polka-dotted marsupials a bit bigger than a squirrel, Northern quolls (Dasyurus hallucatus) are among the very few mammals that practice the lifestyle called semelparity, living for only a single, albeit intense, breeding season. They’re the furry, four-legged equivalent of salmon or petunias. Among Northern quolls, males are the one-season wonders. Females live for two or three.
Male quolls grow up in about 11 months. “Then obviously something switches in their brains, and they go, ‘Oh my gosh, I need to find as many females as possible and mate with them,’ ” Wilson says. “They run extraordinarily long distances to find the females. They pretty much stop thinking about finding food.”
All that running is hard on the fellas. “You get these beautiful big males that two weeks later have lost their hair, lost their muscle mass,” he says. “They can hardly walk. They’ve got puffy sores all over them, and they keel over and die.”
Just how far and fast these binge marathoners travel should become clearer as Wilson and his colleagues collect data from quoll-tracking instruments. The researchers can already say how maneuverable the species is, which could be an overlooked but important feature of how the imperiled animals cope, or don’t, with introduced predators such as cats and foxes.
Quolls can race around sharp corners, averaging 1.5 meters per second in a 135-degree turn, Wilson and his colleagues report in the Feb. 1 Journal of Experimental Biology. That’s on a quoll speedway (with protective rubber in the potential marsupial crash zone) custom built with an adjustable bend. The track sits on the remote Groote Eylandt, an island where Northern quolls are abundant. Scientists chased quolls through the track with a soft plastic block on a pole. “The animals were much faster than we were,” Wilson says.
Wilson takes pains to explain the big issues behind his work to bystanders at the track. But despite the broader importance, even he acknowledges, “When it’s all set up, it looks completely ridiculous.”