Conservationists Eye Return for Giant Native Spider to Chatham Islands
Giant native spiders, once widespread in the Chatham Islands, are now confined to two small reserves. Conservationists are working to restore habitats to allow their potential return to mainland areas.
Key takeaways
- Conservationists are working to facilitate the return of the Rangatira spider to parts of the Chatham Islands.
- The large native spider has been confined to two offshore islands for over a century.
- Habitat restoration and predator eradication are key to enabling the spider's reintroduction.
- The species is currently classified as 'At Risk: Relict' due to its limited range.
Conservationists are exploring the possibility of reintroducing the Rangatira spider, a large native species, to parts of the Chatham Islands. This initiative aims to restore the spider's historical range, from which it disappeared over a century ago.
What Happened
The Rangatira spider, once a prominent inhabitant across multiple islands in the Chatham archipelago, is now restricted to just two small offshore nature reserves: Hokorereoro/Rangatira and Maung’Re/Mangere islands. It has not been documented on the main Chatham Island (Rēkohu Wharekauri) or Pitt Island for more than 100 years. While not facing immediate extinction, the species is classified as "At Risk: Relict" by the Department of Conservation due to its highly limited distribution.
Why It Matters
The spider's current confinement to a small, protected area makes its population vulnerable to environmental shifts or the introduction of new threats. Efforts by the Chatham Islands Landscape Restoration Trust to eradicate predators and restore native ecosystems are intended to create suitable conditions for the species' potential return to broader areas of the Chathams. This expansion would reduce the spider's reliance on its existing island refuges and secure alternative habitats for future generations.
Background
Rangatira spiders are among New Zealand's largest, with females weighing up to five grams before egg-laying. They are described as relatively docile, spending days hidden in tree holes and logs and hunting wētā after dark. Their decline is attributed to habitat loss and the presence of predators, which are believed to have eradicated them from most of their original range.
Key Facts
- The Rangatira spider is a giant native species confined to two remote islands in the Chatham Islands.
- Females can weigh up to five grams before laying eggs, comparable to the weight of a tītitipounamu bird.
- The species has not been seen on the main Chatham Island or Pitt Island for over a century.
- It is classified as "At Risk: Relict" by the Department of Conservation.
- The Chatham Islands Landscape Restoration Trust is undertaking predator eradication to restore ecosystems.
- Successful reintroduction requires forests with large trees, a healthy wētā population, and protection from predators like mice, rats, possums, and weka.
Sources reviewed
Project Chintan independently synthesized and analyzed information cross-checked across the sources listed above.
