Native birds, lizards, eels and fish
A great variety of native and introduced birds, small lizards, eels, bullies (freshwater fish), trout and crayfish live in the park.
Since European settlement the numbers of native birds and insects has diminished due to changes in the forest caused by milling and the effect of introduced animal pests.
North Island saddleback, stitchbird, North Island brown kiwi, kokakō, North Island weka and the North Island thrush have all disappeared from the park in the last 100 years.
While native species have declined, the number of introduced birds has increased.
Despite a reduction in native bird numbers in the park, it is still possible to see and hear many birds such as: grey warblers (riroriro), tomtits (miromiro), fantails (pirairaka), morepork owls (ruru), silver-eyes/wax-eyes, kingfishers (kōtare), Australasian harrier hawks (kāhu), whiteheads (pōpokatea), riflemen (tītipounamu) and the New Zealand pipit (pīhoihoi).
Kererū, tuī and bellbirds (korimako) are also present throughout the forest.
Kererū play a vital role in forest regeneration as their diet of fruits from a variety of shrubs and trees ensures the dispersal of seeds over a wide area. Trees such as tawa, miro and matai are almost totally dependent upon the kererū for seed dispersal.
New Zealand falcon (karearea) and kākā parrot are also occasional visitors to the mountain.
Although largely unnoticed, an abundance of insects inhabit the forest.
A scratch about amongst the leaf litter reveals all sorts of beetles and bugs. An especially good time to look for insects is at night when glowworms can be seen on damp banks.
Glowworms are most numerous from October to February. By torchlight you will see all sorts of beetles and moths feeding.
Three species of native galaxid freshwater fish are found in heavily forested streams within the park: the giant kokopu (which grows as long as 580mm), the short-jawed kokupu, and the banded kokopu.
Other aquatic animals found in the park include bullies, freshwater crayfish, lamprey, long-finned and short-finned eels.
Introduced brown trout have also becomes established in longer streams.
Other animals found more easily at night include small native geckos, one of two families of lizard found in New Zealand.
Geckos feed mainly on insects and other small invertebrates although the forest gecko also feeds on nectar. Geckos have a flattened body with soft loose skin and a large blunt head.
Skinks are the other family of lizards found in New Zealand and one species of these is known to inhabit Pirongia Forest Park. Unlike the geckos, skinks have smooth, round bodies with a small pointed head.
These creatures are mostly nocturnal but are known to bask in the sun.