Flaviemys purvisi
Very Well-Known Member
By Patrick Sawer, senior reporter
9 MAY 2018
A female adder (Vipera herus) CREDIT: ALAMY
A deadly new disease introduced into Britain by exotic snakes has attacked and killed some of the country’s native adders and grass snakes, threatening to decimate their numbers.
The National Trust has warned that pet owners who abandon unwanted exotic snakes such as boa constrictors in the countryside have created a fatal new danger for already threatened native species.
Experts have found evidence that a number of native grass snakes have succumbed to Snake Fungal Disease, which causes lesions on the snake's body, leading to infection and death.
In the latest case a 4ft (1.2m) Dumeril’s boa constrictor from Madagascar was found abandoned at Kinver Edge, on the Staffordshire/Worcestershire border.
That followed the discovery of four American Western Hognose snakes at the same beauty spot.
The trust has been looking after Kinver Edge for more than 100 years and its experts have reported that the number of adders and grass snakes at the site is falling.
They say the habit of abandoning exotic snakes can only serve to further threaten the native population of grass snakes and adders, already under threat from urbanisation and loss of habitat.
The pathogen has been found in 23 species of wild snake in the US and at least three in Europe.
Nigel Hand, a reptile and amphibian ecology who works with the National Trust, said: “We have found evidence of Snake Fungal Disease killing native grass snakes. It appears the strain is a European one and there could also be an indication of the presence of the US strain.
“Dumping non-native snakes into the environment could worsen the threat of Snake Fungal disease, compounding the threat to what is already a declining population of native species.”
“If you add non-native native species in there's a chance pathogens or diseases can cause real problems to a very small adder population. We may end up wiping them out if this happens."
Mr Hand added: "When we found the first one [non-native snake], we thought that potentially it was an escapee but the fact we have found five snakes, we really think there is a case they have been released on this site."
Releasing foreign species of wildlife into the British countryside is illegal and can be punished with a fine of up to £5,000 or six months in prison.
Ewan Chapman, a lead ranger with the National Trust, said the discovery of the boa and Western Hognoses at Kinver Edge had highlighted a growing problem.
“This has happened in other areas, It is not an isolated incident,” he said. “It’s totally irresponsible for people to simply abandon these snakes like this. There are plenty of others who would take them into their homes and look after them properly if the owner can’t manage.
“Our primary concern is they can introduce pathogens and diseases and introduce them to native species.”
Mr Chapman said the sizeable cost of feeding snakes like boas, along with the effort required to prove them with a healthy habitat, could lead owners to dumping them, at a time when ecologists are trying to safeguard native species.
“Snake Fungal Disease is already having a severe effect on snakes in the US. We are trying to stabilise our population of native snakes, such as adders and grass snakes, which are under threat and this could lead to a further decline in their numbers and even localised extinction.”
