Everyone needs good neighbors – and for North American red squirrels, having friends next door increases the odds of survival and reproduction from year to year.
British experts who studied squirrels in Yukon, Canada found that keeping the same neighbors was so beneficial that it outweighed the drawbacks of aging for a year.
Squirrels living in adjacent areas for consecutive years seem to trust each other – meaning they end up spending less time defending their territory.
This, in turn, frees up more time to gather food and raise young.
Living close to relatives, on the other hand, did not seem to improve the red squirrel’s chances of survival – but this could be an artifact of the sample area of their study, the team said.
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Everyone needs good neighbors – and for North American red squirrels, having friends increases the chances of survival and reproduction from year to year, a study finds.
In their study, Dr. Siracusa and colleagues analyzed 22 years of data on the Yukon’s squirrel populations – with a focus on a central territory and immediate environment from a distance of 130 meters, as shown.
“These squirrels are solitary – they each defend a territory with a” center “(food supply) in the middle – so we can assume they are not cooperating,” said paper author and animal behaviorist Erin Siracusa of the University of Exeter.
“Our findings, however, suggest that – rather than despicable contempt – familiarity with neighbors is mutually beneficial.”
“Defending a territory is costly – it takes both energy and time that can be spent gathering food or raising puppies.” ‘
“It may be that after living side by side for a period of time, squirrels reach some sort of agreement about boundaries, which reduces the need for aggression.”
“Competition is the rule in nature, but the benefits mentioned here may explain the evolution of cooperation even between hostile neighbors.”
In their study, Dr. Siracusa and colleagues analyzed 22 years of data on the Yukon’s squirrel populations – focusing on the central territory of each rodent and its immediate surroundings from a distance of 130 meters.
The team examined both the kinship of neighboring squirrels – that is, how closely related they were – and their ‘familiarity’, or how long individuals occupied adjacent areas, using colored tags attached to the animal’s ears.
They also looked at rodent survivability and breeding success – measured as the number of pups conceived for the males, and for the female squirrels as the number of pups that survived at least their first winter.
Squirrels living in adjacent areas for consecutive years seem to trust each other – meaning they end up spending less time defending their territory. This in turn frees up more time to gather food and raise young. Pictured: squirrel pups
“These squirrels are solitary – they each defend a territory with a” middle “(food supply) in the middle – so we can assume they are not cooperating,” said Dr. Siracusa. “Our findings, however, suggest that — rather than despicable disdain — familiarity with neighbors is mutually beneficial.” Pictured, Dr. Siracusa is weighing a female squirrel as part of the study
The researchers were surprised to find that the benefits of having known neighbors outweighed the effects of aging.
Aging alone decreased the annual survival rate from 68 percent (among those four-year-old squirrels) to 59 percent (among those five-year-old), the team noted.
However, five-year-old squirrels servicing all their neighbors had a 74 percent chance of surviving the year, the team found.
“For territorial systems to emerge, the benefit of being territorial must outweigh the cost of defending those resources,” explains Dr. Siracusa.
“So it’s not surprising that we would see the evolution of a mechanism that works to minimize those costs of territoriality.”
The researchers looked at the rodent’s survival rates and success in breeding – which was measured as the number of pups conceived for the males, and for the female squirrels as the number of pups that survived at least their first winter. Pictured, three squirrel pups
Dr. Siracusa said the lack of evidence in the study that kinship is beneficial does not necessarily mean that related individuals are not cooperating.
“Genetic affiliation in the neighborhoods we studied was relatively low, and it’s possible that relatives are important on a smaller scale than the 130-meter radius we used,” she added.
“Other studies have shown that related squirrels are less likely to rattle against each other (an aggressive noise), and relatives will sometimes share a nest to survive the winter.”
“At the risk of becoming poetic about squirrels, I think there’s some kind of interesting lesson here that red squirrels can teach us about the value of social relationships.”
“Red squirrels don’t like their neighbors. They constantly compete with them for food and partners and resources. And yet they have to get along to survive. ‘
“Right now, we see a lot of strife and division in the world, but perhaps this is a lesson worth bearing in mind: Red squirrels need their neighbors, and maybe they do,” she concluded.
The full findings of the study are published in the journal Current Biology.