Giant spiders have biggest mating season ever in UK after thousands are released into wild

The giant fen raft spider has experienced its most successful breeding season on record, thanks to the conservation efforts of Chester Zoo. Chester Zoo released ten thousand giant spiders into the wild to help the species return from the brink of extinction around a decade ago.

The fen raft is one of the UK’s largest and most endangered spider species. In 2011, Chester Zoo began its conservation project by starting its breeding program. The zoo reared hundreds of baby fen raft spiders in individual test tubes - to prevent the spiders eating each other - and raised them to maturity.

Once the spiders were mature enough, Chester Zoo released them back into their natural habitat - wetland areas such as marshes and grazing ditches. The spiders opt to live around slow-moving water and have adapted to hunt on the surface of water, using their long legs to detect prey by sensing vibrations.

As of this year, it is estimated that there are around 10,000 breeding female fen raft spiders which is a remarkable improvement from its near-extinction levels a decade ago.

Fen raft spiders are crucial in maintaining the health of wetlands ecosystems. They help control the populations of various organisms including insects, tadpoles, and small fish. By preying on these organisms, fen raft spiders prevent any one group from becoming overly dominant, which could disrupt the ecosystem.

The presence of fen raft spiders also shows the health of an area of wetland as the species needs clean and water-rich environments to survive. Healthy wetlands are crucial for biodiversity as the areas can support numerous species of mammals, birds, insects and plants.

Chester Zoo’s conservation efforts with reviving the fen raft spider has been incredibly successful. Chester Zoo posted an update on X and wrote: “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.”

As you can imagine, some people aren’t thrilled about an extra ten thousand giant spiders running around.

Someone wrote: “Crikey! Hope they don't come into homes.” But luckily, Chester Zoo has reassured everyone that the fen raft spiders only live in wetland habitats and are completely harmless to humans. Phew.

Another X user wrote: “I mean why?!!!!!! Just keep them for yourself! Maybe try introducing some macaws or something!”