Everyone needs good neighbors – and for North American red squirrels, having friends with them year after year improves their 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 aging by a year.
Squirrels that live in adjacent territories for successive years seem to grow up trusting each other – which means they end up spending less time defending their territory.
In turn, this frees up more time to gather food and raise young.
Instead, living close to relatives doesn’t seem to improve the red squirrel’s survival rates – but it could be an artifact of their study’s sampling area, the team said.
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Everyone needs good neighbors – and for North American red squirrels, having friends with them year after year improves their chances of survival and reproduction, a study found.
In their study, Dr. Syracuse and colleagues analyzed 22-year-old data on squirrel populations in the Yukon – focusing on a central area and its immediate surroundings up to a distance of 130 meters away, as it is. described
“These squirrels are solitary – each defending a territory with a ‘means’ (food) in the center – so we could assume they are not cooperating,” said paper author and animal behavior Erin Siracusa of the University of Exeter.
“However, our findings suggest that – far from reproductive contempt – familiarization with neighbors is mutually beneficial.”
“Defending a territory is expensive – it uses both energy and time, which could be spent gathering food or raising chickens.”
“It may be that after a while they live next to each other, the squirrels reach some kind of agreement on the limits, reducing the need for aggression.”
“Competition is the rule in nature, but the benefits identified here could explain the evolution of cooperation even among conflicting neighbors.”
In their study, Dr. Syracuse and colleagues analyzed 22-year-old data on squirrel populations in the Yukon – focusing on the central territory of each rodent and its immediate surroundings up to a distance of 130 meters.
The team examined both the kinship of neighboring squirrels – that is, how closely related they were – and also their “familiarity”, or how long the individuals occupied the adjacent territories, through colorful tags attached to the animal’s ears.
They also analyzed the survival rates and success of rodents in breeding – which was measured as the number of chicks generated for males and for female squirrels as the number of chicks that survived at least their first winter.
Squirrels that live in adjacent territories for successive years seem to grow up trusting each other – which means they end up spending less time defending their territory. In turn, this frees up more time to gather food and raise young. In the picture: squirrel chicks
“These squirrels are lonely – each defending a territory with a ‘midden’ (food) in the center – so we could assume that they do not cooperate,” said Dr. Siracusa. “However, our findings suggest that – far from reproductive contempt – getting to know neighbors is mutually beneficial.” In the picture, Dr. Syracuse weighs a squirrel as part of the study.
Researchers were surprised to find that the benefits of having family neighbors outweighed the effects of aging.
Aging alone has 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, the team found.
“For territorial systems to emerge, the benefit of being territorial must outweigh the costs of defending these resources,” said Dr. Siracusa.
“So it’s not surprising that we should see the evolution of a mechanism that works to minimize these territorial costs.”
The researchers looked at the survival rates and success of rodents in breeding – which was measured as the number of chicks bred for males and for squirrels as the number of chicks that survived at least their first winter. In the picture, three squirrel chicks
Dr. Siracusa said that the lack of evidence in the study because kinship is beneficial does not necessarily mean that relatives do not cooperate.
“The genetic relationship in the neighborhoods we studied was relatively low and relatives may be important on a smaller scale than the 130-meter radius we used,” she added.
“Other studies have found that related squirrels are less likely to rattle (an aggressive sound) at each other, and relatives will sometimes share a nest to survive the winter.”
“At the risk of growing poetically 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. I am in constant competition with them for food, colleagues and resources. And yet, they must understand each other in order to survive.
“In the world right now, we see a lot of conflicts and divisions, but maybe this is a lesson worth taking into account: red squirrels need their neighbors and maybe we do,” she concluded.
The full results of the study were published in the journal Current Biology.
HOW DOES THE COLORED WILL CLEAR THE RED WILL?
Red squirrels are native to the UK and spend most of their time in trees.
However, gray squirrels were introduced to Britain in the late 19th century in North America.
Originally introduced as an ornamental species, they soon spread to Britain and other European nations, such as Italy.
Gray squirrels carry a disease called squirrel parapox virus, which does not appear to affect their health, but often kills red squirrels.
Gray squirrels are more likely to eat green acorns, so they will decimate the food source before the tomatoes reach them.
Tomatoes cannot digest ripe acorns, so they can only eat green acorns.
When red squirrels are under pressure, they will not reproduce as often, which amplified the initial problem of the gray squirrel.
Another huge factor in their decline is the loss of forests in the last century, but road traffic and predators are also threats.
Currently, it is estimated that only 15,000 red squirrels could remain in the UK.