Environment

New Zealand's Threatened Native Mammals

Greater Short-Tailed Bats and Maui's Dolphins are critically endangered in New Zealand.

New Zealand is an island country located in the South Pacific Ocean, southeast of Australia. It covers an area of 103,483 square miles and is divided between 2 principal islands and several smaller islands. This area is covered in beaches, mountains, valleys, and lakes. Its geographic variations and relative isolation have helped New Zealand form unique flora and fauna. Changes to its environment, however, have led to significant species loss. This article takes a look at some of the threatened mammals native to New Zealand.

Threatened Native Mammals of New Zealand

New Zealand Greater Short-Tailed Bat

The New Zealand greater short-tailed bat is listed as critically endangered. Because it has not been seen since 1967, it is possible that this species is already extinct. This bat is endemic to New Zealand and is believed to inhabit old-growth forests. It has a wingspan of 11.8 inches and is approximately 3.5 inches in length. In 1963, the Kiore rat, an invasive species, was introduced to the islands, causing a detrimental decline in the population size of the greater short-tailed bat as well as other animals. At this time, a conservation effort was underway for various animals, unfortunately, the New Zealand greater short-tailed bat was not recognized as a distinct species and was not included in these efforts. Recently, the IUCN has received unconfirmed reports of bats on the Big South Cape and Putauhina islands. Some organizations are planning to survey the area to determine if it is this bat species.

Maui’s Dolphin

Maui’s dolphin is considered the smallest and rarest dolphin species in the world. It is a subspecies of Hector’s dolphin. The females are bigger than the males and can grow to approximately 5.5 feet in length. It is grey, black, and white in color and has a round dorsal fin. This species only inhabits the western coast of New Zealand’s North Island and is considered endemic. Maui’s dolphin is listed as critically endangered and has not benefitted from any local conservation efforts. In fact, the government of New Zealand has doubted the population size and habitat as reported by the International Whaling Commission. In 2014, the government removed the protected status of 1,158 square miles of the West Coast North Island Marine Sanctuary (its principal habitat) to begin drilling for oil. Estimates suggest only 43 to 47 individuals are currently alive. Of these, only 10 are mature females.

Hector’s Dolphin

Hector’s dolphin, like Maui’s dolphin, is endemic to New Zealand and can be found off the coasts of South Island. It grows to an average of 4.5 feet in length and weighs between 88 and 132 pounds. This dolphin is listed on the IUCN Red List as endangered since 2000 due to a consistent decline of more than 50% of its population over 3 generations. Its current population is estimated at just over 7,000, although some recent studies suggest that has increased to 12,000 in the last year. This dolphin species is directly threatened by the fishing industry’s use of gillnets, which trap the dolphins underwater and prevent them from surfacing for air.

This is just an example of a few of New Zealand’s threatened and endangered native mammal species. The chart published below has a more complete list which includes various whales and bats as well as a sea lion.

Environmental Threats

Because New Zealand was once such an isolated ecosystem, its habitats and wildlife are particularly sensitive to changes. European explorers brought invasive species to these islands that quickly took over competition, reducing the population of native plants and animals. Additionally, industrialization and rapidly growing population have contributed to the need for more natural resources and larger urban areas. Logging, agriculture, fishing, and development have resulted in widespread deforestation, habitat destruction and fragmentation, air and water pollution, and unbalanced species populations. To combat this, the government has protected in varying degrees approximately 30% of the country’s area. Unfortunately, as seen with the Maui dolphin, this protection can be lifted at any time for economic gain.

New Zealand's Threatened Native MammalsScientific Name
New Zealand Greater Short-Tailed Bat
Mystacina robusta
Maui's DolphinCephalorhynchus hectori maui
Hector's DolphinCephalorhynchus hectori
New Zealand (Hooker's) Sea LionPhocarctos hookeri
New Zealand Lesser Short-Tailed Bat
Mystacina tuberculata
New Zealand Long-Tailed Bat
Chalinolobus tuberculatus
Southern Right WhaleEubalaena australis
Humpback WhaleMegaptera novaeangliae
Sperm WhalePhyseter macrocephalus
Sei Whale
Balaenoptera borealis
Fin Whale
Balaenoptera physalus
Blue Whale
Balaenoptera musculus

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