Squirrels and Adoption

Adoption is noticed in social animals but it is much less common among asocial animals. A study by Guelph University Prof. Andrew McAdam, along with researchers from the University of Alberta and McGill University, has revealed that asocial red squirrels will adopt pups that have lost their mother.

The scientists say social animals like lions and chimpanzees, are often surrounded by relatives, so it's not surprising that a female would adopt an orphaned family member. But red squirrels live in complete isolation and are very territorial. The only time they will allow another squirrel on their territory is the one day a year when the females are ready to mate or when they are nursing their pups.

The researchers found that relatedness plays a critical role in deciding whether a neighbouring squirrel will adopt or not. In the five adoption cases recorded by the researchers, the pups were nieces, nephews, siblings or grandchildren to the adoptive mother.

Adoption jeopardizes the survival of their offspring. So why does an animal adopt in the first place. It is still a mystery. The researchers say in some cases it might be a good bet to adopt as under the right conditions, an animal can propagate more copies of its genes by helping relatives to raise their offspring than by producing offspring of their own.

Squirrels will only adopt an orphaned pup when the costs of adoption are low and when the orphans carry a large percentage of the same genes such as siblings, nieces or nephews rather than more distant relatives. Amazingly squirrels are able to assess which pups are related or not.

Details are published in the latest issue of journal Nature Communications