Does make the best mums

A new study by Canadian researchers from the University of Lethbridges Department of Psychology has revealed that mule deer females go to extra lengths to protect their fawn from danger.

Washington, May 12 : A new study by Canadian researchers from the University of Lethbridge's Department of Psychology has revealed that mule deer females go to extra lengths to protect their fawn from danger.

The vigilant deer mothers run to the rescue, even from valleys as far as 1,640 feet away, standing guard and risking their own lives until the predator leaves. "Mule deer females confront coyotes, and defend fawns and even other adults throughout the year," said lead author of the study Susan Lingle.

Lingle and her team observed deer interacting with predators on a large cattle ranch in southern Alberta.

At first they noticed that female mule deer cooperated to form nurseries in which they raised their fawns. While sometimes the juveniles strayed, or at other times, the females left the nursery for food, drink or other reasons, they would at once run back to the rescue if a predator, usually a coyote, approached the fawns.

To test whether the deer mothers' single-minded instinct to save juveniles appeared to drive the behaviour, or if other factors also played a role, the scientists played fawn distress calls to both mule and whitetail deer moms.

They found that while the latter only responded to calls made by their own offspring, the mule deer made no such distinctions.

The mule does usually identify their young by a combination of scent, sight and sound, but since scent works only at close distances, mothers farther away relied on sight or sound alone, which meant they often didn't get it right. Even so, such an error proved right for the fawns, Lingle said.

According to her, protecting all fawns, and not just their own, also help the deer maintain a strong, near delay-free fight or flight response.

"A female's ability to defend her own offspring hinges on an overriding motivation to respond aggressively as soon as she hears distress calls. Since fawns only utter these calls when capture is imminent, a delay of just a few seconds could have fatal consequences," said Lingle.

"Another possible explanation could be that the deer simply benefit by banding together in groups regardless of species. More mothers on fawn-guard increases the chances that a coyote will leave all of the young alone," Discovery News quoted her as saying.

The findings are scheduled for publication in the journal Animal Behavior.

ANI