Marmot-spotting is a common perk of hiking in the French mountains but it could become increasingly rare as rising temperatures threaten the species’ survival.
Researchers have noticed a fall in reproduction among marmots – also known as groundhogs – in the Pyrenees.
They have been observing the animals at 15 sites since 2016, when they found that 15% were not reproducing. In 2021, this was up to 53%. Warmer winters mean a thinner covering of snow, so that marmots’ underground burrows are less well insulated, which is particularly detrimental to females.
“The more the thickness is reduced, the less she is protected from the cold, and she will have to spend more energy keeping warm and have less for reproducing,” ecologist Fanny Mallard told The Connexion.
She coordinates the Sentinelles du climat programme, which studies the effects of climate change on biodiversity in the Nouvelle-Aquitaine region.
Hot, dry summers, like the one we have just had, are similarly hazardous due to the impact they have on plant life.
“They are currently eating to fatten up for the winter. It’s important for females to be robust to have enough energy to reproduce well.
“This year of drought will impact food sources and the survival of marmots.”
Three times a year, naturalists observe each of the 15 sites and count the number of adult and baby marmots.
Their findings support the conclusions of a 20-year study of marmots in the Alps. Sentinelles du climat, which is run by the Cistude Nature association, also used modelling to project the data over the coming decades according to different scenarios presented by the Intergovernmental Panel on Climate Change.
Habitat could be reduced by half by end of century
It found that marmots’ habitat in the Pyrenees could be reduced by almost half by the end of the century without a concerted effort to reduce global emissions.
Other factors, including “people’s new appetite for nature since the Covid pandemic, and if there is more disruption due to tourists”, could also have an impact on the presence of the species, Ms Mallard added.
Other species studied by the programme are under even greater threat, such as the Pyrenean frog, which is found in cold, fast-moving streams.
“The higher the temperature, the less oxygen there will be in the stream.”
This, combined with the threat of increasingly extreme floods due to melting snow and glaciers, means they are particularly endangered.
“Biodiversity in Nouvelle-Aquitaine is destined to be drastically impoverished,” Sentinelles du climat wrote on its website after six years of research and data analysis.
At the same time, with temperatures above 30C increasingly common in the mountains, these areas are becoming hospitable to new creatures, Ms Mallard said.
She offered the example of the common wall lizard, often spotted in towns and villages, which is increasingly present in mountainous areas.
The mountain-dwelling Pyrenean rock lizard, meanwhile, is having to migrate higher still, researchers believe. “Species which live at high altitude are going to move even higher up, but mountains are not infinite.
“They are bound to disappear if this continues.”