Tuesday, November 05, 2024

ARACHNOPHOBIA TRIGGER WARNING

Giant spiders that can grow to size of human hand thriving in the UK

TOO LATE

Hannah Al-Othman North of England correspondent
Tue 5 November 2024 
THE GUARDIAB

There are thought to be 10,000 female fen raft spiders now in the wild across the UK.Photograph: Jill Mead/The Guardian


Thousands of giant spiders that can grow to the size of a human hand are thriving in the UK, thanks to a successful breeding programme from Chester zoo.

The fen raft spider is a harmless arachnid that plays a vital role in aquatic ecosystems, but 15 years ago was on the brink of extinction because of habitat loss.

Chester zoo worked with the RSPB to raise hundreds of baby spiders, keeping them separate in test tubes so that they did not eat one another.


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The spiders were hand-fed with tweezers in the zoo’s bio-secure breeding facility until they were big enough to be released into the wild.

This year, the spiders have had their best mating season on record, Chester zoo said, with the RSPB estimating that there are 10,000 breeding females across the UK.

According to London zoo, the stretched-out leg span of a fen raft spiders is typically 65-70mm – roughly the width of a human palm or the length of a newborn rat.

The zoo was also involved in the breeding programme, along with other members of BIAZA, the British and Irish Association of Zoos and Aquariums.

The spiders were hand-reared between 2011 and 2013, and later released into the wild. Chester zoo said it had helped to release “thousands” 10 years ago, adding “you can’t miss them, they grow to be the size of your hand!”

“We’re super proud to be part of this conservation breeding rescue programme, working alongside our friends at the RSPB to prevent the extinction of the fen raft spider,” the zoo said in a post on X.

Also known as the great raft spider, the semi-aquatic arachnids have a chocolate-brown body with cream stripes along the side and are able to walk on water. They live in unpolluted fens and marshes.

The first fen raft spider population in the UK was identified in 1956 by the arachnologist Dr Eric Duffey, at the source of the River Waveney in East Anglia.

“Of course, there is also nothing to fear from increased numbers of spiders,” Dave Clarke, who heads up London zoo’s Friendly Spider Programme, wrote in a blog post.

“This is a huge conservation success, both for the spiders and the wider habitat restoration driving the success. And more natural bio-controls out there (even if this species is never coming into human areas) are only a good thing.”

Giant spider population booms in UK as species the size of rats enjoy record mating season

Athena Stavrou
Mon 4 November 2024 
THE INDEPENDENT

Fen Raft spiders can spin a web as large as 25cm and can grow to the size of a rate - but are completely harmless to humans (Algirdas/Creative Commons)


One of the UK’s largest breed of spiders have had the biggest mating season on record as efforts to re-establish the species in the UK receive a major boost.

From near-extinction 14 years ago, the number of fen raft spiders are now soaring increasing thanks to recent conservation efforts.

Only a handful remained as their wetland homes were destroyed by humans in 2010, but work to bring them back from the brink of extinctions saw the likes of Chester Zoo release thousands back into the wild a decade ago.

The zoo has continued to breed the spider, and has now revealed that 10,000 resident breeding females have had the biggest mating season on record.

Sharing the news on social media, Chester Zoo said: “Ten years ago we helped release THOUSANDS of GIANT spiders back into the UK!

“The fen raft spiders were bred right here at the zoo, and we’re super happy to report there’s now more than 10,000 breeding females... and they’ve just had the biggest mating season on record! You can’t miss them, they grow to be the size of your hand! Honestly, you’re so welcome.”



Fen Raft spiders can spin a web as large as 25cm and can grow to the size of a rat - but are completely harmless to humans.

The fen raft spider has a brown or black body with white or cream stripes along the sides. With a span of up to almost three inches (8cm), they are the largest of the UK’s 660 native species of spider.

The species only lives in fens, marshes and wetlands, using their long hairy legs to skate across the surface of the water.

The spiders are not venomous but are semi-aquatic and can run across the water’s surface to capture their prey. Their diet includes other spiders, damselflies, dragonfly larvae and even fish and tadpoles.

They are easiest to spot in grazing marsh ditches from June to September.



They are easiest to spot in grazing marsh ditches from June to September. (Charlie Elder)

Describing how it saved the unique species back in 2011, Chester Zoo said: “Our experts set about rearing hundreds of baby spiders in individual test tubes (so they didn’t eat each other!)”

It added: “Our team delicately hand fed tiny flies to each of the hundreds of spiderlings using tweezers, day in, day out, for weeks on end in our bio-secure breeding facility.

“Eventually, the young spiders grew strong enough to be returned to their natural habitat, which our partners worked to restore, and we released them in their hundreds!”

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