New Zealand may seem like a tranquil paradise, but lurking in its forests, mountains, and beaches are a surprising number of venomous and poisonous creatures. If you’re planning a trip to New Zealand, it’s important to be aware of the dangerous animals that inhabit the islands.
If you’re short on time, here’s a quick answer to your question: The most poisonous animals in New Zealand include the katipo spider, yellow-bellied sea snake, bluebottle jellyfish, and native skinks. Always take precautions and be vigilant when exploring the New Zealand wilderness.
Venomous Spiders
Katipo Spider
The katipo spider is one of the most venomous spiders found in New Zealand. There are two species of katipo – the redback katipo (Latrodectus katipo) and the black katipo (Latrodectus atritus). These spiders are cousins of the Australian redback and black widows.
Katipo spiders have a neurotoxic venom that can cause severe pain, sweating, headache, vomiting, abdominal cramping, hypertension, and paralysis in humans if left untreated (Toxinology, 2023).
Katipo spiders build messy-looking cobwebs in logs, rocks, driftwood, and other natural hiding places. They have a rounded abdomen with red stripes (redback katipo) or a smooth black abdomen (black katipo).
Bites most often occur when people encounter the spider while gardening, collecting firewood, or doing other outdoor activities. According to statistics from the University of Auckland, there are around 12-18 katipo bites per year, but no deaths since the arrival of antivenom in the 1940s (Spider Identification, 2021).
Redback Spider
The Australian redback spider (Latrodectus hasseltii) is an invasive species that has established populations in urban areas of New Zealand after likely hitchhiking in cargo shipments. Redback spiders can be identified by the prominent red stripe on their abdomen and spherical egg sacs.
Their venom contains powerful neurotoxins that can cause severe pain, sweating, vomiting, headache and hypertension in humans (Spider Identification, 2021).
According to research from Canterbury University, redback spiders have spread to at least 20 locations across New Zealand, including Auckland, Napier, New Plymouth and Nelson. They often live in dry, dark places like sheds, woodpiles, toilets or under rocks.
Around 12-20 redback bites are reported each year in New Zealand, but no deaths have occurred since the availability of antivenom. Prompt medical treatment is still essential (Bradford et al., 2022).
White-Tailed Spider
The white-tailed spider (Lampona cylindrata) is native to Australia but can also be found in gardens, houses and outbuildings across New Zealand. These spiders have cylindrical bodies and a white spot at the end of their abdomen.
Despite rumors, there is little evidence that their bite causes necrotic ulcers in humans. According to Arachnologist Norman Platnick at the American Museum of Natural History, lesions attributed to white-tails are likely coincidental infections.
A study by the Canterbury District Health Board found bacteria present in less than 3% of 124 reported white-tail bites, none of which led to infection (CDHB, 2008). Most bites occur indoors while people are sleeping or getting dressed.
The venom may cause a short stinging pain but this subsides over a few hours. So while white-tails get a bad rap, they tend to mind their own business and do not pose a serious public health risk.
Dangerous Marine Life
Box Jellyfish
The box jellyfish is widely regarded as one of the most venomous marine animals in New Zealand. With tentacles up to 3 meters long, their sting can be excruciatingly painful and cause skin welts, muscle cramps, breathing difficulties, and potentially death if not treated promptly.
Box jellyfish are mostly found north of Gisborne on the North Island, especially during summer months. Wearing a full-body stingproof swimsuit offers the best protection when swimming in areas inhabited by box jellies.
Bluebottle Jellyfish
The bluebottle, also known as the Portuguese man o’ war, is a common sight around New Zealand beaches. Its long tentacles can deliver a painful, though rarely life-threatening, sting. Bluebottles are carried by winds and currents and often wash up on beaches in large numbers.
Their translucent blue bodies and bubble-like floats make them easy to spot and avoid. If stung by a bluebottle, remove any tentacles, wash the affected area with seawater (never freshwater), and apply ice packs to relieve the pain. Seek medical attention if symptoms persist.
Yellow-Bellied Sea Snake
The yellow-bellied sea snake is a highly venomous snake that occasionally drifts to New Zealand shores from populations in tropical northern Australia. They can grow over 1 meter long and have a distinct yellow underbelly.
Their venom is potent and can cause muscle paralysis, though antitoxins make deaths rare. If you spot a yellow-bellied sea snake while at the beach, give it plenty of space and do not try to pick it up. Notify local authorities so they can safely relocate it.
Though encounters are uncommon, being aware of what these snakes look like and keeping your distance is vital for staying safe.
Poisonous Lizards
Native Skinks
New Zealand is home to several species of native skinks, some of which are venomous. The most infamous is the Otago skink (Oligosoma otagense), found only in Central Otago. This large, brown skink has a mild venom that causes swelling and numbness if a person is bitten.
Luckily, Otago skink bites are very rare as these reptiles are shy and tend to avoid humans. Two other venomous skinks are the speckled skink (O. infrapunctatum) and the robust skink (O. alani). Both species are found in scrublands and forests in northern and central New Zealand.
Bites may result in redness and tingling around the bite site but are not considered dangerous.
Researchers have analyzed the venom of New Zealand skinks and found it contains unique compounds. Some compounds show promise as pharmaceutical agents. For example, a peptide found in Otago skink venom may be useful for treating erectile dysfunction.
As venomous New Zealand skinks are protected species, conservation efforts ensure populations remain healthy so these lizards and their intriguing venoms persist on the landscape.
Geckos
There are no poisonous geckos native to New Zealand. However, a recent invasive arrival is posing new concerns – the Asian house gecko (Hemidactylus frenatus). Native to tropical Asia, these geckos arrived in New Zealand via shipping containers in the early 2000s.
Populations are now established in northern parts of the North Island. The Asian house gecko can deliver a painful bite leaving small puncture wounds. Though not poisonous per se, bacteria from their mouths can infect bites and cause inflammation or infection. Keeping wounds clean is important.
Another downside of Asian house geckos is they compete with native geckos for food and habitat. Conservation groups are tracking Asian house gecko populations and implementing control strategies in hopes of limiting their impact and spread.
The Department of Conservation provides educational resources so homeowners know how to discourage these new gecko invaders. While native geckos like forest gecko (Mokopirirakau granulatus) and green gecko (Naultinus elegans) are harmless and protected, this problematic Asian newcomer is proving poisonous in its own right.
Poisonous Plants
New Zealand has several native plants that can be quite dangerous or even fatal if ingested by humans or animals. Some of the most poisonous ones that visitors should know about are the tutu plant, tree nettle, and castor oil plant.
Tutu Plant
The tutu plant (Coriaria arborea), also called the New Zealand tutu, is a large shrub with pretty white or pale pink flowers. However, the entire plant is extremely toxic – even just a few berries or leaves can kill a human or animal.
The toxic honey produced from the flowers has caused deaths when consumed. According to authoritative government conservation websites like DOC, the toxin causes convulsions, vomiting, and delirium if ingested.
Tree Nettle
The tree nettle or ongaonga (Urtica ferox) looks like an ordinary nettle but reaches the size of a small tree or large shrub. Its leaves and stems are covered in stinging hairs that inject toxins causing severe pain, which according to Te Ara Encyclopedia can last from several days to over a year!
While not normally fatal, the agonizing stings can cause problems like paralysis and have even killed livestock like horses in the past.
Castor Oil Plant
The castor oil plant (Ricinus communis) is an invasive species in New Zealand grown ornamentally for its attractive leaves and seed pods. However, the seeds contain the deadly toxin ricin – just a few can kill an adult human, and there is no antidote, warns governmental biosecurity website MPI.
Some cases involved children eating the seeds, mistaking them for beans. So this is definitely a poisonous plant for visitors and residents alike to avoid!
Conclusion
While New Zealand has its fair share of poisonous creatures, with proper precautions there is no reason to avoid this beautiful country. Being knowledgeable about the potential dangers, wearing protective clothing, and staying vigilant will allow you to fully enjoy New Zealand’s stunning landscapes and unique wildlife safely.
