Critically Endangered Desertas wolf spiders have been moved from the Desertas islands of Madeira to Bristol Zoo where a captive breeding programme has been established to conserve the species.
Approximately 25,000 wolf spiders are left in a single population on the Deserta Grande island.
Invasive grasses have been spreading across the landscape, swamping the natural vegetation and binding the soil in which the arachnids burrow into for shelter.
Mark Bushell, Curator of Invertebrates at Bristol Zoo, has just returned from Desertas Grande with 25 juveniles, which he intends to breed with the aim of releasing some of the spiders back onto the island over the next few years.
He said, “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.”
The arachnids are also vulnerable to huge losses from one catastrophic event, such as disease or flooding.
Despite being on the International Union for Conservation of Nature’s (IUCN) Red List of Threatened Species, the wolf spider population is not protected by any specific legislation.
Wolf spider numbers are small for an invertebrate population, yet in the absence of terrestrial mammals on the volcanic island the species has established itself as one of the top predators, making them a key species in the ecosystem.
Bristol Zoo’s collaboration with Madeira National Park and the IUCN also involves sending horticulture experts from the zoo to Desertas Grande to help preserve the habitat the spiders live in.