UK’s largest snake that disappeared from the wild in 10,000 years is breeding again

A species of snake has returned to the wild after a 10,000-year hiatus, having started breeding in the wild after escaping from a zoo in Wales.

The Aesculapian rat snake is a non-venomous reptile that can grow up to 6 feet in length.

It was once native to Britain before the last Ice Age, but is now more commonly found in southern Mediterranean and Balkan countries.

In the 1960s they were imported from Italy by Robert Jackson, the founder of the Welsh Mountain Reptile Zoo in Conwy.

In the early 1970s, baby snakes were found on the grounds of the zoo – initially believed to be grass snakes due to their yellow markings, but later confirmed to be Aesculapian rat snakes, which had begun to reproduce and slowly spread beyond the zoo.

Credit: Alamy

Tom Major, a PhD student at Bangor University who has been studying the snakes for five years, says the species now has a stable population in the Colwyn Bay area.

Major said they had a “limited range”, were reluctant to cross roads and had trouble finding prey – usually eating rodents up to the size of rats.

Speaking to NorthWalesLive, he said: “We found a snake yesterday which was born around September 2018 and weighed eight grams in 2019.

“Three years later, it weighed 15 grams, about the same as an HP pencil.

“Even taking into account six months of hibernation each year, and the cooler climate, it’s an extraordinarily slow growth rate. This suggests he may have only eaten once or twice in the past three years.

Esculapians can grow up to two meters long in southern Europe, making them one of the largest snakes on the continent.

However, in colder North Wales, Major thinks they are unlikely to grow much beyond 1.5 meters – although that still makes them the longest snakes in Britain.

Credit: Alamy
Credit: Alamy

After starting with field surveys, Major began radio tracking nine snakes last year and plans to repeat the exercise this summer.

“We learned that they have a limited range, moving up to 500m per day, and are often limited by things like roads,” he said.

“They spend long periods of time hiding in hay bales and in the walls of buildings.”

Major said people needn’t be alarmed if they spot a snake, adding: “On the mainland the snake co-exists with all other species, including the animals you find here like badgers, stoats and domestic cats.

“For a naturally balanced ecosystem, diversity is generally a good thing. It is used to living alongside humans and there is little to no evidence that it causes harm.

Despite this, the Aesculapian Ratsnake is considered a ‘management priority species’ for Wales, meaning the Colwyn Bay population has been monitored since 2004 so that a ‘rapid response can be taken if necessary said the North Wales Wildlife Trust.

If you find an Aesculapian snake in the Colwyn Bay area, report it to Tom Major at [email protected]