Red squirrel taking an adopted baby from nest. (Photo/Ryan W. Taylor)
In another life, I must’ve been a dog. Whenever I’m out walking and see a squirrel, I have an almost uncontrollable urge to see how close I can get to it before the scrappy rodent scrabbles up a tree. Inevitably, a staring contest ensues, which the squirrel usually ends up winning.
My suppressed animal urges aside, I do notice something kind of educational about squirrels. They tend to be alone. When they’re not, they are usually chasing each other like crazed maniacs in a not too friendly manner without regard to life or other happenings.
That’s why it might come as a surprise that they practice a typically human behavior – they adopt. And they adopt outside their social group. A new study by researchers at the University of Alberta determined that red squirrels will take in abandoned or otherwise parent-less young and raise them as their own, a seemingly altruistic act. The behavior turns out not to be as charitable as it sounds – the squirrels do get a survival perk. But the discovery is nonetheless an unusual one in the animal kingdom, with its own squirrely flare to boot.
Jamieson Gorrell, a Ph.D. student in evolutionary biology at the University of Alberta and lead of the study, was observing a population of Yukon red squirrels and noticed a lone female had taken a baby from an abandoned nest to raise as her own. When Gorrell sifted through 20 years of red squirrel research from the area, he found four other instances of the same behavior. Not only that, but in each account, the baby adopted was a relative.
Gorrell found that despite their antisocial tendencies, red squirrels are still able to recognize, and decide to care for, relatives. Right now the predominant notion is that the chitter-chatter squirrels screech out to mark territory or ward off others contains vocal clues about relativity. So an encroaching squirrel could hear the calls of another adult, and recognize kinship. If that other mother disappears, the encroaching squirrel may recognize the kinship of the abandoned nest and take action.
In addition to the novelty factor of the behavior, the study authors also state that this finding proves a long-standing evolutionary theory true. It is a concept known as Hamilton’s Rule, which suggests that despite “the law of the jungle and survival of the fittest,” animals can be altruistic.
Though for red squirrels, it’s a tempered altruism. The red squirrel is still helping out a member of its bloodline, and will only help one baby out of a litter. Adopting more than one is “out of the question,” according to the study, as the strain of adding more than one baby to a single mother’s already full house would outweigh any benefits.
You can read more about the study in the online journal Nature Communications, or visit this link http://www.redsquirrel.ca/KRSP/Media.html to get more info, cute pics, and free copy of the study.