Great raft spider conservation
Image: Helen Smith
The UK's biggest spiders, which have a leg span of up to 8cm, are being released in the wild.
Great raft spiders only live in wetlands, and are able to glide on water. However, there are very few remaining in the wild.
Ecologist Dr Helen Smith and experts from 10 zoos across the country have reared thousands of the spiders as part of a programme to revive the three remaining great raft populations.
The spiders are now being reintroduced to their former habitat in the Norfolk Broads.
Natural England, the Broads Authority, the BBC Wildlife Fund and volunteers have all helped to fund the release of the 5mm spider babies from their test-tubes at the RSPB's Strumpshaw Fen reserve.
Dr Smith said the project's intention is not to flood the fens with giant spiders, but merely to repair the damage already done.
"With animals that are this rare you can make lots of arguments about food chains and food webs and how important that is," she said. "We simply don't know what pulling out one brick will do further down the heap."
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