Cave closure gave huge rare spider ‘peace’ from humans. Now, numbers are growing
One of New Zealand’s largest spiders — with legs reaching over 5 inches long — is a creature that prefers “solitude and a bit of peace and quiet,” according to wildlife officials.
The Nelson cave spider — New Zealand’s largest native spider — is rebounding after officials closed their cave to visitors in 2022, according to a June 18 news release from the New Zealand Department of Conservation.
“It’s not scary — it’s scared of us,” officials said.
The population of the “rare and unusual” species, found in the South Island’s “Crazy Paving Cave,” was steadily declining prior to the closure, likely a result of human interference, officials said.
“The cave has a low ceiling, and it’s quite small, so people get close to the spiders,” senior ranger Scott Freeman said in the release.
Freeman said humans unknowingly disrupt the spider’s natural behavior “with bright lights, vibration, sound, and the heat they bring into the cave.”
Nelson spider counts in the cave are up to 33 in 2025 compared to eight in 2022, officials said. Rangers have also found evidence that the spiders are breeding.
The spiders hang egg sacs “like small golf balls” from the cave ceilings, according to officials. These sacs, which can contain as many as 50 babies, have also been disturbed by visitors.
This is a relatively long-lived spider species, with babies taking up to three years to mature. Many other species live for just one year, officials said.
“Nelson cave spiders evolved separately from the rest of the world for millions of years and are thought to be directly descended from the earliest true spiders,” wildlife experts said. “They may be the missing link between primitive and modern spiders.”
Officials said the Nelson cave spider was the first spider species protected under New Zealand’s Wildlife Act.
“Crazy Paving Cave” is in the Ōparara Valley on the west coast of New Zealand’s South Island.
It is named for its dried-out floor of ancient sediment that has cracked and curled, resembling “large, distorted paving stones,” according to officials.
Officials have not determined if or when they will reopen the cave.
This story was originally published June 18, 2025 at 4:13 PM with the headline "Cave closure gave huge rare spider ‘peace’ from humans. Now, numbers are growing."
