Book 11, Question 64
Why Do Squirrels Sometimes Raise Orphans?
Squirrels sometimes raise orphans because relatives can help each other out! Squirrels usually care for their own young, but sometimes a mother adopts babies that have lost their mother. It is most common when the babies are related.
More fun facts
- North American red squirrels mostly live alone, and each one defends its own territory.
- Over 19 years and 2,230 litters, scientists saw red squirrel mothers adopt orphaned babies five times.
- Every adoption was by a relative of the orphan, and orphans with no relatives living nearby were never adopted.
- Adoptions happened only when the benefit to the orphan, weighed by how closely related they were, was bigger than the cost of feeding an extra baby.
- That pattern fits Hamilton's rule, a famous idea that explains why animals sometimes help relatives at a cost to themselves.
- Another red squirrel study found that females lived longer on average when their daughters lived nearby.
Sources: National Institutes of Health, National Institutes of Health
Questions kids ask
Do squirrels adopt any baby they find?
Not in the red squirrel study. Mothers adopted only orphans that were their relatives.
Are red squirrels social animals?
Not very. They live alone and guard their own territories, which makes their rare adoptions of relatives especially interesting.