A new study shows that living next to experienced neighbors allows squirrels to survive and breed successfully.
The study measured the one-year survival of North American red squirrels – and found that keeping the same neighbors was so beneficial that it outweighed the negative effects. getting a year older.
However, living close to genetic relatives did not improve survival rates.
The research – part of the Kluane Red Squirrel Project – used 22 years of data on squirrels in Yukon, Canada, within the traditional lands of Champagne and Aishihik First Nations.
“These squirrels are isolated – each protecting land with a ‘midden’ (food stash) at the center – so we can assume that they will not co-operate,” said the lead author. Dr Erin Siracusa, from the Center for Research in Animal Behavior at the University of Exeter.
“However, our findings suggest – far from being a breeding ground – knowing each other is mutually beneficial.
“Protecting land is expensive – it uses both energy and time that can be spent collecting food or raising puppies.
“After a certain period of time staying together, squirrels may reach a kind of ‘border’ agreement, reducing the need for attack.
“Competition is the rule in nature, but the benefits outlined here could explain the evolution of cooperation even among hostile neighbors.”
The study looked at the “neighborhood” within 130 meters of core area, examining both “relationship” (how closely the squirrels were connected) and “knowledge” (how far squirrels were). half residing in adjacent areas).
Researchers also studied survival rates and breeding success – for males this was measured by the number of pups placed, and for females it meant pups surviving their first winter.
The team was surprised that the benefits from experienced neighbors outweighed the effects of age.
Age alone reduced annual survival rates from 68% (age four) to 59% (age five).
However, squirrels that supported all their neighbors had a 74% chance of surviving a year from the age of five.
“While we have no evidence of direct co-operation among experienced neighbors – such as working together to fight invaders – it is clear that there will be no benefit if their neighbors die,” said Dr Syracuse.
“Regardless of the type of interaction, our study shows that even solitary species have important social relationships.”
Dr. Siracusa said the lack of evidence in the study for a relationship to be beneficial does not mean that relatives do not cooperate.
“Genetic relationships in the neighborhoods we studied were relatively low, and it is possible that a relationship could be significant at a scale smaller than the 130m radius we used,” she said.
“Other studies have found that related squirrels are less likely to prey (aggressive sound) on each other, and relatives sometimes share a nest to survive the winter.”
The Kluane Red Squirrel Project was initiated at the University of Alberta and was led by researchers at the University of Alberta, the University of Guelph, the University of Michigan and the University of Saskatchewan.
Funders included the Canadian Natural Sciences and Engineering Research Council, the National Science Foundation, the American Society of Mammalogists and the North American Arctic Institute.
The study, published in the journal Conventional biology, entitled: “Neighbors who know, but do not relatives, strengthen health in a terrestrial mammal.”
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