Island spiders dwarf cousins
Each day in Te Papa’s curators tell the story of an interesting item from the museum’s collection.
The Rangatira spider is one New Zealand’s largest and rarest arachnids. Unique to the Chathams, it is found only on islands free of introduced predators, with Rangatira Island (for which it is named) its main stronghold.
First discovered on Pitt Island, these spiders have since disappeared from there, probably due to the arrival of mice.
They are related to the nursery web spiders of mainland New Zealand and are quite similar looking. However, they are considerably larger and their 10cm leg span is double that of their mainland cousins. Like the nursery web spider, the female Rangatira spider builds a special web to protect her young for a short time after they emerge from their egg sac.
Rangatira spiders don’t build a web to catch food; instead, they actively hunt their prey. After dark, the leaf litter on Ra- ngatira Island seems to come alive with insects, providing plenty of opportunities for these spiders to feed.
One of the back legs of the spider in the photo looks different to the others. She probably lost a leg when younger and grew another. As replacement limbs do not reach normal size, one leg is shorter than it should be.
By Phil Sirvid, collections manager, entomology.
Photo: MICHAEL HALL/TE PAPA
Rare creature: Rangatira spider (Dolomedes schauinslandi).