Everyone needs good neighbors, and for American red squirrels, having friends by their side each year improves the chances of survival and reproduction.
British experts studying squirrels in the Yukon, Canada, found that keeping the same neighbors was so beneficial that it outweighed the disadvantages of having one more year.
Squirrels living in adjacent territories in successive years seem to grow and trust each other, that is, they end up spending less time defending their territory.
This, in turn, frees up more time to pick up food and raise young.
In contrast, living close to relatives did not appear to improve red squirrel survival rates, but that could be an artifact in the sample area of their study, the team said.
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Everyone needs good neighbors, and for American red squirrels, having friends alongside them year after year improves their chances of survival and reproduction, according to a study.
In their study, Dr. Syracuse and colleagues analyzed 22-year-old data on Yukon squirrel populations, centered in central territory and their immediate surroundings up to a distance of 130 meters away, such as represented
“These squirrels are lonely, each defending a territory with a‘ midden ’in the center, so we could assume they are not cooperating,” said Erin Siracusa, author of the paper and animal behaviorist at the University of Exeter.
“However, our findings suggest that, far from reproductive contempt, familiarity with neighbors is mutually beneficial.”
“Defending a territory is expensive: it uses both energy and time that could be spent collecting food or raising young”
“It may be that after some time living side by side, the squirrels come to some kind of agreement on the borders, reducing the need for aggression.”
“Competition is the rule by nature, but the benefits identified here could explain the evolution of cooperation even between opposing neighbors.”
In their study, Dr. Siracusa and colleagues analyzed 22-year-old data on Yukon squirrel populations, centered on the central territory of each rodent and its immediate surroundings up to a distance of 130 meters. away.
The team examined both the kinship of neighboring squirrels (i.e., their relationship to each other), and their “familiarity” or how long they occupied the adjacent territories using colored labels attached to the animal’s ears. .
They also examined the survival rates and success of breeders in rodents, which was measured as the number of offspring bred for males and for female squirrels as the number of offspring that survived at least their first. winter.
Squirrels living in adjacent territories in successive years seem to grow and trust each other, that is, they end up spending less time defending their territory. This, in turn, frees up more time to pick up food and raise young. In the photo: squirrel cubs
“These squirrels are lonely, each defending a territory with a‘ midden ’in the center, so we could assume they are not cooperating,” Syracuse said. “However, our findings suggest that, far from reproductive contempt, familiarity with neighbors is mutually beneficial.” In the image, Dr. Syracuse weighs a female squirrel as part of the study
Researchers were surprised when the benefits of having family neighbors outweighed the effects of aging.
Aging only reduced annual survival rates from 68% (among four-year-old squirrels) to 59% (among five-year-olds), the team noted.
However, the five-year-old squirrels that kept all their neighbors had a 74% chance of surviving the year, according to the team.
“In order for territorial systems to emerge, the benefit of being territorial must outweigh the costs of defending these resources,” Dr. Siracusa explained.
“Therefore, it is not surprising that we see the evolution of a mechanism that works to minimize these costs of territoriality.”
The researchers examined survival rates and breeding success of rodents, which were measured as the number of offspring bred for males and for female squirrels as the number of offspring that survived at least their first winter. . In the photo, three squirrel puppies
Dr. Syracuse said the lack of evidence in the study on the benefit of kinship does not necessarily mean that related people do not cooperate.
“The genetic relationship to the neighborhoods we studied was relatively low and it is possible that relatives may be important on a smaller scale than the 130-meter radius we used,” he added.
“Other studies have found that related squirrels are less likely to wobble (an aggressive sound) with each other, and relatives sometimes share a nest to survive the winter.”
“At the risk of becoming poetic about squirrels, I think there’s a kind of interesting lesson that red squirrels can teach us about the value of social relationships.”
“Red squirrels don’t like their neighbors. They are in constant competition with them for food, companions, and resources. And yet, they have to get along well to survive. ”
“In the world right now, we’re seeing a lot of conflict and division, but maybe that’s a lesson worth keeping in mind: red squirrels need their neighbors and maybe us too,” he concluded.
The full findings of the study were published in the journal Current Biology.