How do warmer winters affect hedgehogs?

Wildlife experts on the Channel Islands say warmer temperatures are leading to fewer hibernating hedgehogs and an increasing number of parasite infestations.

The Jersey Hedgehog Preservation Group (JHPG) said milder winters have allowed the mammals’ food sources to remain available, meaning hibernation is less necessary.

Alderney Wildlife Trust (AWT) said higher temperatures are likely to increase the number of parasites on hedgehogs, causing the creatures to be underweight and therefore requiring them to forage during the winter months.

Traditionally, hedgehogs hibernate between November and mid-March in a winter nest, or hibernacula, made from dry leaves and grass.

JHPG’s Dru Burdon said she believed the change in hibernation habits was “due to climate change”.

She said: “We don’t have the cold winters we used to have, so hedgehogs don’t need to hibernate as their food is always available to them as long as the ground isn’t frozen.

“If we have a few cold nights below 5C, they may hibernate or just stay in their nests for a bit, but they don’t seem to disappear for long in winter like they used to.”

2023 was the hottest year on record globally, and the nine hottest years all date back to 2015.

Guernsey experienced its second hottest year on record in 2023, according to the Bailiwick’s Met Office.

Jersey experienced its hottest year on record in 2023 and temperatures in the islands are on average warmer than mainland UK.

“Awake all year round”

Guernsey Society for the Prevention of Cruelty to Animals (GSPCA) chief executive Steve Byrne said it was “incredibly difficult” for hedgehogs to hibernate as temperatures rarely drop below 5C C (41°F).

He said: “We see and rescue hedgehogs 365 days a year. Due to our weather and climate they are indeed awake all year round, as they would anywhere the temperature does not drop to the required level so that they go into hibernation mode.

Roland Gauvain, president and CEO of AWT, said some of the island’s bats, rats and moles also appear to have changed their behavior.

He said: “We have anecdotal evidence that there are many more species, particularly small mammals, that would have historically hibernated during the colder months of the year and now remain active throughout the year. ‘winter.

“This is not to say that significant numbers of hedgehogs are not still hibernating.

“However, enough animals now appear to remain active, and therefore in view of the general public, that the number of reports of ‘unusual activity’ continues to increase.”

He said the cause of this change in behavior was “probably complex”, but that rising temperatures were “probably a significant factor”.

“It could, however, be a combination of warmer winters making foraging more possible.

“But there could also be wetter and warmer summers and autumns, which would allow hedgehogs to have multiple litters, making it more likely to have underweight juveniles and females who need to continue feeding during the winter to gain or regain weight,” he said. explain.

In November, the Alderney Animal Welfare Society reported it had a “worrying number” of very sick hedgehogs in its care.

Veterinary nurse Kelly Huitson said some were suffering from ticks as well as symptoms of an unidentified illness.

Mr Gauvain said: “We can assume that warmer winters are also likely to benefit these pests and could be partly responsible for their increase, although this could also be due to the introduction of new species to the island by various methods.”

“Research needed”

British Hedgehog Preservation Society chief executive Fay Vass said the reports were so far accecdotal.

She said: “Hibernation is triggered by various factors, two of which are temperature and food availability.

“So if it stays warm and food is readily available, hedgehogs may hibernate for less time, if at all – research would be needed to be able to say with certainty that this is happening.”

Follow BBC Guernsey on X And Facebook. Follow BBC Jersey on X And Facebook. Send your story ideas to [email protected].

Learn more about this story

Related web links