Ever see a kangaroo hopping past your window? In parts of the United States and Canada, instead of wild grass-eating kangaroos, they have wild flesh-eating pumas. And when humans are around, these pumas kill for food more often, but eat less of each kill.

Wild pumas are known as cougars or mountain lions and roam some neighbourhoods in Canada and the U. S.

Usually, a puma can feed on the carcass of a killed deer for up to five days.

But, as humans encroach on their territory, this slow-paced luxury is one that urban pumas cannot afford.

GPS tracking in Santa Cruz Mountains
Researcher Justine Smith used GPS collars to track the hunting patterns of 30 wild pumas in the Santa Cruz Mountains, California.

She found female pumas living close to human neighbours were changing their behaviour, spending less time eating what they kill, and killing 36% more deer each year to compensate.

“When females make a kill in a highly developed area, they spend less time at their kill site, and move farther away to bed down during the day,” says Justine.

Puma mums too busy to kill, eat and care?
But avoiding humans and missing meals can leave a big cat hungry.

With female pumas also responsible for raising kittens, Justine’s guess is that puma mums may end up exhausted.

“Killing deer takes tremendous effort… Such a dramatic increase in kill rates could have effects on reproduction,” she speculates.

I wrote this article for CSIRO’s popular science magazine: Double Helix.
Be sure to check out Justine’s youtube channel to see the big cats in action: