
The first record of a Noble False Widow spider feeding on a Pipistrelle bat has been published by scientists from NUI Galway’s Ryan Institute.
A false widow was found to have caught a bat in its web in an attic in England.
The study was published in the international journal Ecosphere and adds to a swath of information showing the impact the false widow can have on native animals.
It is the first time this type of spider has been found preying on a bat anywhere in the world and the first time it has captured a vertebrate of any kind in Britain.
“We have been working on the Noble False Widow for the past five years, and have learnt a great dal about this species – yet, we are still surprised by its ability to adapt to new environments and make the most of the resources available,” said Dr Michel Dugon, Head of the Venom Systems Lab in the Ryan Institute.
“It is a truly remarkable species.”
Wildlife artist Ben Waddams discovered two different bats, one a young pup and the other a larger adult, caught in silk webs in his attic in Shropshire.
The Pipistrelle bat is considered a protected species in Britain.
The false widow spider has a history of preying on native species. It was found to be feeding on a protected species of native lizard here in Ireland three years ago.
Lead author of the study Dr John Dunbar said we are only seeing the beginning of the false widow’s effect on Ireland’s wildlife.
“In more exotic parts of the world, scientists have been documenting such predation events by spiders on small vertebrates for many years, but we are only beginning to realise just how common these events occur.
“Now that this alien species has become well established in Ireland and Britain, we are witnessing such fascinating events on our very own doorstep.”
Dr Dunbar said the false widow is known to feed on native species of larger animals such as snakes and lizards and this latest incident is further evidence of the spider’s “invasive” nature.
The spiders are able to prey upon animals much larger than themselves by using a fast-acting venom causing neuromuscular paralysis.
“In the last three years alone, we have observed two occasions of the alien Noble False Widow capturing and feeding on protected species of vertebrate animals in Ireland and Britain,” said Aiste Vitkauskaite, a researcher at the Venom Systems Lab.
“As the Noble False Widow continues to expand its range and increase populations across Ireland and Britain, we should expect to observe similar predation events on small vertebrate animals by this spider, including protected species.”
A video about the Ryan Institute’s study is available via NUI Galway’s YouTube channel.
The research team are also calling on members of the public to report sightings of the Noble False Widow spider to falsewidow@nuigalway.ie.