There are thought to be just 4000 adult spiders left in the wild, as the species live only on one of the Desertas Islands, near Madeira, Portugal. The spiders are critically endangered as their island habitat is being destroyed by invasive plants.
In order to prevent the species from dying out, Bristol Zoo’s curator of invertebrates, Mark Bushell, travelled with zoo vet Richard Saunders to Desertas Grande last year and brought back 25 spiders.
Bushell himself oversaw the breeding attempt, and says he is very pleased at its success. “Because this was the first time this species had ever been taken into captivity to breed, it was a steep learning curve. After some of the female spiders were mated, it was an anxious wait to see if they would produce egg sacs. We were thrilled when they did, and to see the tiny spiderlings emerge was fantastic – a real career highlight,” he said.
The spiderlings were tiny and delicate, measuring just 4mm in diameter, and were so precious that they were kept in separate containers, each with sterilised soil, and were individually fed fruit flies.
With the operation successful, Bristol Zoo is now putting into motion its plans to transfer hundreds of spiders to other zoos across the UK and Europe, setting up a co-operative attempt to conserve the species, which will also involve efforts to make Desertas Grande more spider-friendly.
“Establishing the world’s first captive breeding programme for this species is a fantastic step towards protecting it for the future,” continued Bushell. “It is a beautiful and impressive creature, but its natural habitat is being altered by invasive plants. There are simply not enough rocky and sandy areas of habitat left for the spiders to burrow and hide in. The result is a deadly game of musical chairs, whereby the spiders are competing for fewer and fewer burrows.
“In addition to the loss of habitat, one single catastrophic event could wipe out the species entirely. Now we have successfully created a ‘safety net’ population here at Bristol Zoo to help safeguard this impressive creature for the future.”
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