New Zealand's native frogs have several distinctive features, which make them very different from frogs elsewhere in the world:
- they have no external eardrum
- they have round (not slit) eyes
- they don't croak regularly like most frogs
- they don't have a tadpole stage. The embryo develops inside an egg, and then hatches as an almost fully-formed frog. The young of most species are cared for by their parents - for example, the male Archey's frog may carry his young offspring around on his back.
Native frog species
New Zealand originally had seven species of native frog. Three species have become extinct since the arrival of humans and animal pests, like rats, in New Zealand. The four remaining species are:
The Hochstetter's frog is the most widespread native frog and has been sighted around the upper half of the North Island, including at Waipu, Great Barrier Island, the Coromandel, central North Island, and the Raukumara Ranges.
It is generally dark brown, grows up to 48 mm long, has partially webbed feet and has more warts than the other native frogs.
Image: Greg Sherley
Archey's frog (Leiopelma archeyi) are only found in the Coromandel and in one site west of Te Kuiti. It is the smallest native frog, growing up to 37 mm long. It lives in misty, moist areas around 400 m in altitude.
One of the world's most endangered frogs, the Hamilton's frog (Leiopelma hamiltoni) is only found on Stephens Island in the Cook Strait.
Image: Sabine Bernert ©
Maud Island frog
This frog is found on Maud Island in the Marlborough Sounds. In 1997 DOC transferred some Maud Island frogs (Leiopelma hochstetteri) to Motuara Island.
Maud Island frog
Image: Sabine Bernert ©
Frogs are declining everywhere in the world. More than most creatures, frogs are sensitive to disease, pollution, chemical poisons and environmental changes, as they absorb many things through their sensitive skin.
Fossil records show that our native frogs were spread throughout both the North and South Islands several thousand years ago. The four remaining species have declined significantly in range and in numbers over the past one to two thousand years, as land has been cleared of forest and predators have been introduced.
Hamilton's frog is the most critically endangered species, with less than 300 individuals remaining. Fossil records show it was once spread from Waikato to Punakaiki. Now it survives only on Stephens Island, where it is carefully managed by DOC.
DOC has created a second population of the frogs on the island, enclosed in a predator-proof fence because tuatara occasionally eat frogs.
Frogs are vulnerable to introduced predators such as rats and cats. In late 1999, a sighting of the aggressive Eastern banjo frog in Auckland also raised fears that if this alien invader gets a foothold, it will out-compete native frogs in their habitat.
DOC has a Native Frog Recovery Group that coordinates management and research into native frogs to help with their conservation.
The impact of 1080 on native frogs has been investigated, and methods for frog monitoring and translocation are being developed and improved. Frog distribution and their numbers are also being documented.
In 1997, 300 Maud Island frogs were transferred to Motuara Island – the first-ever translocation of a native frog between islands. To date, this transfer has been successful.
Establishing a second population of the frog in another location is insurance against a disaster, such as fire, wiping out a sole surviving population. A separate population of Hamilton's frog has also been established on its home on Stephens Island and is monitored closely by DOC.
DOC is also using an innovative new method – a photo stage – to identify individual Archey's frogs. A highly endangered species, identifying individuals allows us to monitor the frogs and better understand what factors are leading to the species' decline.
You can help
As native frogs are small, well-camouflaged and nocturnal, they are hard to find. You can assist DOC greatly by reporting any sightings of native (and introduced) frogs.
Record carefully the location, the type of habitat (stream edge, forest floor), the time and date you sighted them, and if possible take photographs.
DOC is also interested in records of introduced frogs as populations may transmit disease, or directly compete or predate native frogs. Use our introduced frog identification key to find out what species you have found.
Avoid touching the frogs, because you may damage their sensitive skin. If you do touch them, make sure your hands are wet.