Kauri Comparison: Ngāokeoke (Velvet worm)

Crawling through the leaf litter, ngāokeoke are a peculiar sight!

Velvet worms (Onychophora) are a group of invertebrates that look a bit like caterpillars, but they are not insects. The ngāokeoke (velvet worms of Aotearoa) are all from the family Peripatopsidae, which encompasses the Southern species of velvet worms, including those from Australia and South America. Velvet worms are interesting because they are considered ‘living fossils’ due to their uniqueness compared to other invertebrates, and the fact that they appear to have remained unchanged for 500 million years.

New Zealand peripatus (Peripatoides novaezealandiae). Image by L Timmo CC-BY-NC. Source: iNaturalist

Ngāokeoke usually live in forests, but can also be found in a range of vegetated areas that are not too dry. Like caterpillars, ngāokeoke have lots of legs, but unlike leaf-eating caterpillars, they are carnivores, eating prey by shooting them with a sticky liquid and consuming them once they have been dissolved.

There is great diversity within the group, but also within each species, with colouration, number of legs and other traits differing. In Aotearoa, there are currently 10 described species but there are at least 30 more species to be described (Trewick et al., 2024).

Ngāokeoke recently won the New Zealand ‘bug of the year’ competition, run by the Entomological Society of New Zealand. This has put the invertebrate on people’s radar, and the hope is that more will be discovered about these beautiful animals. 

Image of a ngāokeoke (Peripatoides indigo) by strewick Source: iNaturalist CC-by 4.0.

Same or different? 

Velvet worms and kauri trees differ in their species abundance in Aotearoa New Zealand. Kauri (Agathis australis) are the only agathis species found in Aotearoa, whereas there are at least 10 described ngāokeoke species within the same genus. Kauri does have some agathis ‘cousins’ in Australia, the Pacific and Southeast Asia. However, kauri are the southernmost species within the genus, able to withstand cooler temperatures. Because kauri is New Zealand’s only Agathis species, it means that it is all the more important to protect them; once it is lost, there are no other similar species that might be able to take up its ecological role. 

Diversity of different species and diversity within a species is also important because it acts as a buffer against threats to extinction, particularly when it comes to climate change. The diversity within the ngāokeoke group means that there may be some individuals, or some species, that can survive the changing climate. The loss of kauri due to logging decreased the population to 1% of its original range. This drastic decrease in population means that the diversity within the kauri tree species would’ve also greatly reduced.

If all kauri have a similar environmental tolerance, then ecological shifts that come with climate change could destroy the whole population. Additionally, a lack of diversity can also reduce disease resistance, which is already seen with kauri dieback, where there is little to no natural resistance in trees. This is why a multitude of methods is needed to combat the spread of kauri dieback, from propagating seedlings to tracking upgrades and carrying out phosphite treatments.

To learn more about kauri protection, see our kauri protection page.