Leaving home benefits male squirrels but not females, study shows

Male red squirrels in North America that live away from their home population reap better benefits in life while female squirrels do not, a study from the University of Alberta has found. 

The study, released Friday morning, looks at 30 years worth of data on the red squirrel population in the Yukon. It found that male squirrels that leave the place they were born tend to live longer and have more offspring. 

April Martinig, a doctoral candidate in the department of biological sciences, is the lead researcher of the study.

She said male squirrels that move away tend to live six months longer than the average squirrel, which has a life span of approximately five years.

Red squirrels are the common species seen around Edmonton. 

"They have red hair with some black and some beige or white on their chest … they also make a lot of rattles, which is this high-pitched alarm call they vocalize to say where their territory is," she said. 

Male squirrels also have better outcomes in mating because because female squirrels prefer to mate with newcomer males.

Female squirrels don't benefit 

The study also discovered that female squirrels don't benefit as much when they leave their home turf.

When females move away, they lose the support of nearby family.

Juliana Balluffi-Frye

"Despite that they're a rather asocial species … in the winter, when it's really cold, like right now, they will nest with relatives especially when they're the same sex and females," Martinig said. 

"When you stay home as a female, you get a lot of investment from your mother and also your female siblings."

Intergenerational effect

Martinig looked at data gathered from 2,000 red squirrels. She said the study also found an intergenerational effect, something she didn't expect.

Despite having highly attractive fathers, the sons of squirrels that had moved did not have high levels of offsprings like their parent.

"For female squirrels, what we ended up seeing was the same effect but for their daughters ... so for males that left, their sons had a negative effect. And then for females that left, their daughters were negatively affected as well," she said.