Researchers have found that female red squirrels showed high levels of multimale mating and would even mate with males that had similar genetic relatedness, basically mating with their relatives.
Researchers from the University of Alberta, in Edmonton, Alberta, Canada and the University of Sheffield in Sheffield, England, United Kingdom studied a population of red squirrels over a period of three years near Kluane National Park in southwest Yukon.
While males mating with multiple females is quite common in the animal kingdom, females that multi-mate is much harder to explain.
Through their observations, it was noted that when female red squirrels chose a mate to copulate with, genetic relatedness did not play a factor.
"In males, the benefits of multi-female mating are well established, but in females the benefits of having many offspring is limited, making the reasoning for multimale mating more puzzling," said Jeffrey Lane, who conducted the study while obtaining his PhD at the University of Alberta.
The researchers also found that the relatedness of parents had no effect on the neonatal mass and growth rate of their offspring. As well, whether or not an offspring survived to one year of age wasn't affected by having related parents either.
"Detailed investigations into the social and genetic context of multimale mating in red squirrels and other mammalian species should help to provide insight into the evolution and maintenance of this behavior," said Lane.
This research appears in this month's Animal Behavior.