Male arctic ground squirrels go through puberty every year. As if that wasn’t hard enough, now the children have problems, too.
Climate change appears to be causing them to emerge from hibernation earlier, according to an article published Thursday in the journal Science. That’s important, because it can skew the timing of an animal’s mating cycle.
Usually, males come out of hibernation before females to prepare for the spring mating season. They need time to return to sexual maturity every year because their testosterone levels plummet during the winter.
Then the children woke up. But scientists have found that as temperatures rise, female ground squirrels emerge 10 days earlier than previously thought. The researchers think it is related to the earlier thaw of the soil.
Meanwhile, the male hibernation pattern did not appear to have changed.
“This study shows that males and females of the same species can respond differently to different conditions,” said Helen E. Chmura, a US Forest Service research ecologist and lead author of the paper. Climate Change. “This could have important implications for reproduction.”
The squirrel trouble is part of a much larger crisis. Around the world, wildlife is struggling. On land, the main reason is that humans occupy too much of the planet, erasing the biodiversity that existed before. In the oceans, the main problem is overfishing. Climate change is making survival more difficult.
At present, arctic ground squirrels are still abundant in the wild. The International Union for Conservation of Nature classifies them as least concern, meaning they are not threatened or in need of conservation efforts. But the paper says the new hibernation mismatch “has the potential to affect their probability of survival”.
Any decline in squirrel populations could disrupt local food webs. Almost all Arctic predators, from wolves to eagles, rely on them as a food source.
Although the Arctic is warming faster than any other region on Earth, there is relatively little research on how this warming affects animals. This new paper, covering more than 25 years in Northern Alaska, is one of the first long-term research projects to provide strong evidence that warming is directly changing the physiology of northern species. Pole.
“This study is relatively unusual because it shows that warming is directly affecting mammals,” said Cory T. Williams, assistant professor at Colorado State University and co-author of the study. . “Some people might say, ‘OK, going up 10 days in 25 years doesn’t seem that fast.’ But in terms of climate, that’s incredibly fast.”
Arctic ground squirrels may look cute, but males can be very territorial. They fight a lot during mating season, some of which are deadly. They have tails, but not as long and bushy as squirrels found further south. And they make distinctive whistles that can easily be mistaken for the chirping of a small bird. Some Alaska Natives call them parka squirrels because their fur creates a nice and warm ruffle to the hood of the coat.
Scientists have long been interested in their hibernation patterns.
During their long winter sleep, squirrels’ core body temperature can drop to about 27 degrees Fahrenheit, or about minus 3 degrees Celsius, with their resting heart rate dropping to as low as three beats per minute. Understanding more about that process could lead to advances in hypothermia, a medical treatment in which body temperature is lowered to prevent injury. It is sometimes used after cardiac arrest.
The most pressing challenge, the scientists say, is understanding the changes taking place in the Far North.
Dr Williams said: “The big gap is just understanding what is happening in the Arctic as a whole. “This study shows why we need long-term projects to understand the changes that occur at different levels.”
