Garden spider amputates its own leg


A garden spider has been filmed amputating its own leg.

BBC Earth web editor Tim Edwards was filming the spider wrapping up a wasp when he noticed the unusual behaviour.

Spiders are known to sever their limbs as a protective response, and naturalists suggest the spider may have been stung by its prey.

Mr Edwards said the spider is a frequently-encountered inhabitant of his garden that makes its web across his footpath.

After filming it wrapping up its prey he noticed it starting to act differently - pausing and becoming less adept at its task.

"So it went from being very skilful to very cack-handed in the space of about a minute," he said.

In his footage, the spider can be seen "stroking" its leg before the leg drops to the ground.

"I kept filming for a while to verify that it had only seven legs," said Mr Edwards.

"I immediately assumed it had been stung though - [that] seemed the only reasonable explanation."

Mr Edwards asked colleagues for more information on his footage and wildlife radio producer and presenter Brett Westwood was able to provide an answer.

After consulting the literature, Mr Westwood agreed that "I suspect as Tim Edwards says that it was stung by the wasp and is now removing the limb to prevent the venom spreading."

This process of self-amputation is known as autotomy and spiders commonly regenerate the missing limb in their next moult.

The European garden spider is also known as the garden cross spider due to the white cross marking on its back.

It weaves distinctive webs and is one of the most recognisable spiders in the UK where it feeds on flying insects such as butterflies and wasps.

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