Britain’s largest species of snake breeding in North Wales

A species of SNAKE that escaped over half a century ago is breeding in the wild in the Colwyn Bay area.

The Aesculapian rat snake, more commonly found in the southern Mediterranean and the Balkans, is a non-venomous snake that was the subject of study for Tom Major, a PhD student at Bangor University.

The species generally hunt rodents (hence their name) and are reluctant to cross roads, reaching up to 6 feet in length.

With a stable population in the Colwyn Bay area, this has allowed easy study of the species.

AFTER: Tom Major (right) radios a colony of Aesculapian ratsnakes. Photo: Dr. Wolfgang Wuster

Their growth rate is incredibly slow, weighing only a few grams over several years, suggesting that some only eat a few times a year.

The Colwyn Bay colony is believed to be the largest in the UK, with Mr Major estimating their numbers to be made up of 70 adults and 120 juveniles.

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Although it can reach two meters in length on the mainland, the colder and wetter climate of North Wales should limit growth to just 1.5 metres.

The Aesculapian Ratsnake arrived in Conwy in the mid-1960s when Robert Jackson, founder of the Welsh Mountain Zoo, imported reptiles from Italy.

North Wales pioneer: Tom Major inspects one of the snakes studied.  Photo: Nathan RousliTom Major inspects one of the snakes studied. Photo: Nathan Rousli

In the 1970s, juveniles were found within the grounds of the zoo and were first thought to be grass snakes due to their yellow markings.

Some conservationists hailed their arrival as a ‘returning’ species – they were once native to Britain before the last Ice Age and are not considered a pest.

Although they do not avoid humans, they often coexist with a variety of different species, being known to peacefully inhabit gardens with dogs, badgers, and other animals.

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Despite this, the snake is a management priority species for Wales, with the Colwyn Bay population being monitored since 2004 by the North Wales Wildlife Trust.

Tom Major, whose research is sponsored by the Welsh Mountain Zoo, began with field surveys before moving to radio tracking last year, which he will resume this summer.

North Wales Pioneer: "John" relaxes on the table.  Photo: Tom Major“John” relaxes on the table. Photo: Tom Major