Hochstetter’s frog
Hochstetter’s frog (Leiopelma hochstetteri) lives in forested ranges from Northland (south of Whangārei) to East Cape, usually alongside streams.
The frogs are brown or greenish, with partial webbing on the hind toes. Females grow to 4.7 centimetres (from snout to vent) while males reach 3.8 centimetres. The total population is unknown.
Archey’s frog
There are two main groups of this North Island species (Leiopelma archeyi) – one in the Coromandel Peninsula and the other in the Whareorino Forest, west of Te Kuiti. Archey’s frog is slim, with a glandular ridge running backwards from the eye. Colour is variable and ranges from mainly green (rarely) through combinations of green and brown to mainly brown. Some Whareorino specimens are quite brightly coloured, with pinks and brick reds against the background colour.
The male body length is up to 3.1 centimetres and the female 3.7 centimetres. In 2025 the total wild population was thought to be more than 100,000, but it was threatened by the introduced chytrid fungus disease.
Hamilton’s frog
This species (Leiopelma hamiltoni) is found in two small areas on Stephens Island in Cook Strait. It is mainly brown, but juveniles are sometimes greenish.
It is similar in appearance to Archey’s frog, with a glandular ridge running from the eye, but on average Hamilton’s frog is larger. These are the largest native frogs, with males up to 4.3 centimetres long and females up to 5 centimetres. The total population may be fewer than 300 individuals.
Maud Island frog
Females may reach 4.9 centimetres in length, and males slightly less. They are long-lived – one survived at least 29 years. The Maud Island frog population is estimated at more than 10,000.
Based on measurement and appearance, the Maud Island frog is identical to Hamilton’s frog. In 1998 it was described as a new species, Leiopelma pakeka, because of genetic differences. More recent study based on mitochondrial DNA has questioned this, and it is possible the two frog groups will once again be treated as one species.
Even so, the fact that Maud Island and Hamilton’s frogs live on separate islands means that over time they are evolving differently. From a conservation point of view, two separate populations, with some genetic differences, should be managed as if they are different species, because such diversity is valued.