New Zealand’s fauna has been greatly affected by man-introduced land mammals such as cats, dogs and stoats. Now the threat of extinction hangs over the last species of local land mammals – the New Zealand outgrowth and the New Zealand sheath-winged.
By the time New Zealand was settled by the first Europeans, its unique fauna had already been seriously affected by the introduction of small rats by the Maori. A new wave of invasive species – gray and black rats, domestic cats, pigs and stoats – has called into question the existence of many unusual birds and unlike mammals.
It is worth noting that before the arrival of man, New Zealand was a “bird kingdom”: only four species of local mammals lived on the islands. The well-being of the New Zealand fur seal is not yet in danger: its population numbers over 60,000 individuals. But of the three species of New Zealand bats, one has already completely died out, exterminated by rats.
Now the survival of the two remaining species, the New Zealand outgrowth and the New Zealand sheathwing, hung in the balance. Already, these bats’ ranges are highly fragmented, and their survival is threatened both by introduced predators and by the deforestation and use of poisoned baits by New Zealand farmers to combat the fox bat that threatens their crops.
Recently, wildlife advocates were able to confirm what they had long suspected: bats are often the victims of domestic and feral cats. They found the remains of a winged sheath in the intestines of a feral cat trapped in a forest park, and found the remains of an eaten outgrowth in the yard of a family with a fluffy pet.
While seven dead or injured bats in two years doesn’t seem like much of a loss, there are hundreds of thousands of cats that come out to hunt every night in New Zealand. In this case, their impact on the already small populations of local bats can hardly be overestimated.
Conservationists are urging cat owners to be more responsible about their pets’ leisure time and not leave them free-roaming to limit their ability to hunt local species of animals.
The study was published in the New Zealand Journal of Zoology.