[edit]
Flora[edit]
The plant habitats in Arthurs Pass National Park are quite different on each side of the Main Divide. The eastern side of the park has less rainfall and braided riverbeds, supporting red beech and mountain beech forests with little understorey. Drier valley floors are dominated by grasses, sedges and tussock surrounded by shrubland of matagouri and hebes. Above the bush line are areas of snow tussock, alpine herb fields and scree slopes. The western side of the park has high rainfall, river gorges and dense rainforest.
Fauna[edit]
Whio (blue duck)[edit]
A 2004 survey found only three whio (blue ducks) in the Mingha and Deception Valley area of the park, and by 2021 it was estimated that there were fewer than 3,000 whio left in New Zealand. Seventeen birds were released into the Mingha–Deception Valley area in March 2021, and monitored stoat traps help reduce predation on them.
Kākāriki karaka (orange-fronted parakeet)[edit]
The rarest of New Zealand's kākāriki species, the orange-fronted parakeet (Cyanoramphus malherbi) has twice been declared extinct. It is only found in Arthur's Pass National Park and the Lake Sumner Forest Park and is critically endangered. The Department of Conservation works with Ngāi Tahu to protect the kākāriki karaka, which is a taonga species for the iwi. It is most commonly seen in the Hawdon and Poulter valleys. The bird nests in holes in trees, making it vulnerable to predators. Predator control has been carried out in the Arthur's Pass National Park since 2005. Since 2019, the wild population has increased from about 150-200 birds to around 360 birds.
Kea[edit]
Selfie with kea in Arthur's Pass National Park car park
Kea are regularly seen in both the park and the township. Kea also visit the local ski fields (Porters, Cheeseman, Broken River, Craigieburn and Temple Basin). Kea are at risk of predation by stoats, possums and feral cats. They have also learned to interact with visitors, scavenging or scrounging food and getting into rubbish. This habituates the kea to human food and puts it at risk of eating bait laid down for predators. In 2022, The Department of Conservation and OSPRI (a company working to manage farm animal diseases) funded research near Arthur's Pass to test whether bird repellents would stop kea from interacting with 1080 bait. The year-long study showed that the repellents were ineffective.
The kea is an intelligent, curious and playful bird. When kea visit Arthur's Pass village to scavenge food, they walk across the road or perch on moving cars, sometimes falling off. A conservationist at Arthur's Pass states that between 2020 and 2022, 12 kea were killed by cars including eight in Arthur's Pass village. Visitors are encouraged not to feed kea and to dispose of their rubbish carefully.
Kea also have a habit of eating lead from building flashings and nails, which is toxic and can kill them. In 2018 a project was undertaken to remove lead from houses at Arthur's Pass to reduce the risk to kea.
Great spotted kiwi (roroa)[edit]
The great spotted kiwi or roroa (Apteryx maxima) lives in mountainous beech forest near Arthur's Pass village, which is one of three natural populations of the bird. Their habitat in the National Park means they are less prone to predation than other species of kiwi, and the total population, though classed as vulnerable, is relatively stable at around 14,000 birds. Great spotted kiwi at Arthur's Pass National Park are occasionally killed or injured by cars as they cross the road (and one was killed by a train).
Weka[edit]
Weka are becoming more common in the western side of the park and occasionally in the Edwards Valley. Weka used to be common in the park but by the 1920s had disappeared, possibly due to predation by weasels. From 1961, there were several attempts to reintroduce weka to the Andrews Valley, Taramakau Valley and Poulter Valley areas in the park with birds sourced from the Chatham Islands and the West Coast. In 1968 it was announced that West Coast weka appeared to have been successfully re-established in the Taramakau Valley. Further sightings in the next few years confirmed that the population was growing. They have slowly expanded their territory and predator control has allowed the population to expand towards Arthur's Pass Village.
Mohua (yellowhead)[edit]
The mohua or yellowhead is a small bird that nests and roosts in holes in trees. It was formerly common in South Island beech forests, but populations in the Arthur's Pass area declined by the 1980s due to predation by rats and stoats. The remaining small population was wiped out in 1999–2000 when predator numbers increased dramatically after the beech trees produced huge numbers of seeds (known as a beech mast). In 2022, the Department of Conservation released 41 birds into the Poulter Valley in Arthur's Pass National Park in an attempt to re-establish the mohua population. In 2025 a large beech mast was predicted, so the Department of Conservation increased its predator control efforts in the park and other locations.
Introduced mammals[edit]
Trail cameras show that deer, pigs, possums, feral cats, stoats and mice have been seen at Arthur's Pass. These animals threaten native wildlife in various ways: habitat destruction, eating birds or their eggs, and eating the food sources of native birds. For example, it was discovered that feral cats in the park eat short-horned grasshoppers (Acrididae). The Department of Conservation controls rats, stoats and possums in the park using aerial drops of 1080 (sodium fluoroacetate) and ground control methods such as traps and toxins in bait stations.
