Thanks to a relocation project by a host of conservation organizations, the fen raft spider has made a remarkable rebound from near extinction in the United Kingdom.
The semi-aquatic fen raft (or great raft) spider, distributed widely in Europe, was at risk of disappearing from the U.K. by 2010, with only three known populations left. But a project launched in 2012 to establish the large arachnids in marsh ditches along the Broads -- protected river and lake habitats in England's Norfolk and Suffolk counties -- seems to have changed all of that.
The spider is known for its shimmering nursery webs, which are easy to spot. The Royal Society for the Protection of Birds (RPSB), one of the conservation effort's partners, reports that this year's nursery web count in the Norfolk Broads jumped from 184 webs in 2014 to 480 today.
Officials say the habitat is just right for them to thrive.
"They have exactly the right vegetation mix along the ditches to support their nursery webs and the richness of invertebrate prey that the spiders need," said Tim Strudwick, RSPB site manager at the Strumpshaw Fen nature reserve, in a press release.
The fen raft spider is the largest eight-legger in the U.K. It can grow big enough to send shivers up the spine of any dedicated arachnophobe, with females of the species able to reach about the size of the palm of a human hand.
The spiders are skilled predators that launch attacks from along the water's edge, preying on fare such as water bugs, smaller spiders, and, yes, even small fish. (They're not the only spiders with a taste for fish, as you can see here.)
Not only have they succeeded at amping up their census count, but they've also proven themselves adept at their own form of urban sprawl. At one of the relocation sites, the Suffolk Wildlife Trust nature reserve, the hefty arachnids have spread from an initial 500-meter (0.31 miles) relocation zone to an area of more than 3 kilometers (1.86 miles) of ditches they now call home.
The video below offers a nice look at another fen raft spider relocation project, this one undertaken in 2013 by the Zoological Society of London to establish a group of the spiders in East Anglia: