Squirrel dating is affected by climate change – 6/1/2023 – Environment

Male arctic squirrels go through puberty every year. As if that wasn’t enough, now females are also having a problem.

According to an article recently published in the journal Science, climate change appears to be causing females to emerge from hibernation earlier than expected. This is important because it can disrupt the timing of the squirrels’ reproductive cycle.

Male Arctic squirrels usually come out of hibernation earlier than females to prepare for the spring mating season. They need time to reach their sexual maturity again, a process that is repeated annually because their testosterone levels drop sharply during the winter.

Then the females wake up. But scientists have found that with temperatures rising, females are emerging up to ten days earlier than they did in the past. The researchers think that this is due to the early thawing of the soil.

But the pattern of hibernation in males doesn’t seem to be changing.

“This study suggests that males and females of the same species may react differently to climate change,” said Helen E. Chmura, a research ecologist with the US Forest Service and lead author of the study. “This could have important implications for reproduction.”

The arctic squirrel problems are part of a much larger crisis. Fauna and flora around the world are facing difficulties. On land, the main cause is the fact that humans are occupying too much of the planet, wiping out the biodiversity it once had. In the oceans, the biggest problem is overfishing. Climate change is making survival even more difficult.

Arctic ground squirrels are still abundant in the wild. The International Union for Conservation of Nature classifies them as a species of minor concern, that is, that is not threatened or requires efforts for its conservation. But the study says that the hibernatory time mismatch that began recently “has the potential to affect their likelihood of survival.”

Any decline in arctic squirrel populations could disrupt the local food web. Almost all arctic predators, from wolves to eagles, depend on squirrels for food.

Although the Arctic is warming faster than any other region on Earth, there is relatively little research on how this warming affects animals. The new study, which covers more than 25 years in northern Alaska, is one of the first long-term research projects to provide strong evidence that warming is directly altering the physiological processes of Arctic species.

“The study is relatively unusual because it shows that warming is having a direct impact on a mammal,” said Cory T. Williams, an adjunct professor at Colorado State University and a co-author of the study. “Some people might say, ‘A 10-day advance over 25 years doesn’t seem that fast.’ But in climate terms it’s incredibly fast.”

Arctic ground squirrels can be cute looking, but males can be very territorial. They are often involved in many fights during the mating season, some of them fatal. They have tails, but not long and bushy like squirrels found further south. And they make distinctive hissing sounds that could easily be mistaken for a small bird’s hooting. Some Alaska Natives call them parka squirrels because their fur is used to line coat hoods.

It is not new that scientists are interested in their hibernation patterns.

During their long winter sleep, the temperature of a squirrel’s internal organs can drop to approximately minus 3 degrees centigrade, and their resting heart rate slows down to just three beats per minute. Greater understanding of this process could lead to advances in therapeutic hypothermia, a medical treatment in which the body’s temperature is lowered to prevent injury. The procedure is sometimes used after cardiac arrest.

But, according to scientists, the most pressing challenge is to better understand the changes taking place in the far north of the planet.

“What we’re most lacking is a better view of what’s happening in the Arctic more generally,” Williams said. “This study shows why we need long-term projects to understand the changes that are taking place at different levels.”

Translated by Clara Allain.