Native frogs
Frogs are vertebrates and belong to the class Amphibia. They are the only amphibians naturally occurring in New Zealand. All frogs have delicate, semi-permeable skin that allows them to absorb moisture and air from the surrounding environment.
Maud Island frog
Maud Island frogs are one of 4 endemic frog species found in New Zealand.
Points of interest
How are New Zealand’s endemic frog species different to frogs introduced from Australia?
What is being done to conserve the Maud Island frog?
In New Zealand, we originally had 7 species of native frog, but 3 are now extinct with only 4 native species remaining – Leiopelma hamiltoni (Hamilton’s frog), Leiopelma pakeka (Maud Island frog), Leiopelma archeyi (Archey’s frog) and Leiopelma hochstetteri (Hochstetter’s frog).
Scientific classificationKingdom Phylum Class Order Family GenusAnimalia Chordata Amphibia Anura Leiopelmatidae Leiopelma
The existence of each remaining species is threatened, with two species listed as endangered. They are very difficult to find in their natural environments.
There are also 3 introduced species, all from Australia. These are the brown tree frog, the southern bell frog and the green and golden bell frog.
Southern bell frog
The southern bell frog (Litoria raniformis) was introduced from Australia in the 1860s. It is the largest frog in New Zealand, and while widespread here, it is listed as endangered in Australia. Its call sounds like ‘crawcrocrocrocrok’ – a recording can be heard on the Department of Conservation Identifying introduced frog species page.
A further three species from Australia have formed self-perpetuating populations. Frogs are known as pekeketua or pepeketua in Māori.
Nature of science
Scientists follow strict rules for classifying and naming species. Classifications and names may change over time as new information comes to light. New species are often named after the person who first discovered or described them. For example, Hochstetter’s frog is named after the Austrian naturalist Christian Gottlieb Ferdinand von Hochstetter. Archey’s frog was named after Dr Gilbert Archey.
Unique features
All our native frogs are endemic and belong to a single genus – Leiopelma.
Archey’s froglets on father’s back
After the female frog lays her eggs, they’re fertilised and then guarded by the male. Young frogs are carried around on their father’s back until they are mature enough to survive on their own.
Scientists believe that the ancestors of our native frogs colonised New Zealand over 80 million years ago, when it was still part of Gondwana. As a result, our native frogs have many unique features and life processes that are different to many other frogs:
They don’t have an external eardrum. Although they can make chirping sounds, they don’t croak. Scientists think they use chemicals rather than sounds to communicate.
They have round eyes instead of slits.
They don’t develop a long tongue attached at the front like most other frogs. Their tongue is attached at the back, so they open their mouth and lunge forward to catch their prey.
3 of the 4 species live and breed on dry land. Even the more aquatic species – Hochstetter’s frog – can survive on dry land.
The ones that live on dry land don’t have a free-swimming tadpole stage. The tadpole stage happens inside the egg, and the young hatch out as froglets.
Our native frogs lay a few large eggs, and very few die before becoming froglets.
After the female frog lays her eggs, they’re fertilised and then guarded by the male. Young frogs are carried around on their father’s back until they are mature enough to survive on their own.
Habitat and distribution
Fossil evidence suggests that, before human settlement, our native frogs were widespread. They have now disappeared entirely from the South Island. They are found only in the upper half of the North Island and on a couple of offshore islands. The table below shows their current known habitat, distribution and classification under the New Zealand Threat Classification System.
Species
Habitat
Distribution
Hamilton’s frog 2018 conservation ranking: Threatened – Nationally Critical
Ground dwelling.
Prefers damp crevices between boulders.
Stephens Island in the Marlborough Sounds.
Maud Island frog 2018 conservation ranking: Threatened – Nationally endangered
Ground dwelling.
Prefers rocky areas in native coastal forest.
Maud Island in the Marlborough Sounds. A small population was translocated to Motuara Island in 1997.
Archey’s frog 2018 conservation ranking: At Risk – Declining
Mostly ground dwelling but can climb into bushes and trees when looking for food.
Prefers scrubland and forests in subalpine areas.
Coromandel Peninsula and Whareorino Forest, west of Te Kūiti.
Hochstetter’s frog 2018 conservation ranking: At Risk – Declining
The only native species that prefers the aquatic environment.
Lives in damp areas on the edge of creeks and streams.
Can also survive on farmland and in non-native forests.
Numerous locations in the upper half of the North Island.
Threats to survival
Our remaining populations of native frogs are vulnerable to extinction. They face a number of threats including:
introduced predators
disease
habitat loss
competition with introduced frogs.
Threats to frogs
Dr Phil Bishop, from the University of Otago, talks about the threats facing our native frogs. The most significant threat in New Zealand is introduced mammalian predators.
Point of interest: Before the arrival of humans and the introduction of mammalian predators, what threats do you think our native frogs faced? How were they adapted to deal with these threats?
Save our frogs!
A number of New Zealand agencies, including universities, zoos and government departments, are working together to save our native frogs. The Department of Conservation administers the Native Frog Recovery Group and Native Frog Recovery Plan.
There are 2 main conservation strategies:
Conserving frogs in the wild: Trying to save frogs in the wild involves protecting their natural habitat, removing predators and preventing the introduction of non-native frog species.
Captive management: In captivity, scientists are working on best practice strategies for captive management, breeding techniques and treating frog diseases.
Translocation is a combination of the 2 strategies. This involves physically removing individuals from one population and moving them to an existing population or new habitat. Translocation can be very challenging. Scientists need to work out the right number of frogs to take, balance the number of males and females and transport them safely. They also need to be very careful that the new location is safe and not threatened by disease or mammalian predators. Find out more about translocation in this article.
Related content
The Connected article Kimihia Kermit describes how students and Ngāti Mutunga teamed up with an ecologist to investigate frog populations in North Taranaki. Frogs for the future? is a ready-to-use cross-curricular teaching resource and uses the Connected article Kimihia Kermit as the starting point.
FrogID is an online citizen science project that identifies and records the location of introduced frog species in New Zealand.
Useful links
Visit the Department of Conservation website for more information about frogs and frog conservation.
Visit the NZFROG website for lots of information about frogs in New Zealand and what is being done to save them.
In this recorded webinar from NZ Predator Free, listen to Dr Rebecca Stirnemann talking about our unique frogs and what we can do to help them survive.
Download New Zealand frogs – Pepeketua by Rachael Goddard from the National Library. This free book aims to educate children in a fun and engaging way about conservation, using our four native, rare and endangered frog species.
Stuff news story about the exciting conservation work with the transfer in 2020 of 17 Maud Island frogs to Orana Park as part of the native frog species breeding programme.
Scientists are always learning new things and in 2021 they discovered that the Maud Island frog also spends time in the trees. Knowledge like this is important as the better we understand how our frogs interact with their environment, the better we can provide them with everything they need to breed and thrive. Read about this in this article from Predator Free.
