Cats – domestic, stray and, at the end of the day, feral – caused the extinction of the Stephens Island Wren, a small, flightless bird. It took under two years. Yes, cats made this bird extinct in around 20 months. The bird was an island species and very vulnerable. The bird was known to people for a short time and almost throughout this time they allowed cats to attack the bird while selling specimens of this rare bird to each other for large sums of money.
The root cause of the extinction of Stephens Island Wren was people. They built a lighthouse on the island from 1879 to 1894. Cats were introduced to the island in late February 1894. The bird was noted as a new species around July 1894. It was extinct by the winter of 1895.
There was a competition between two men to achieve the distinction of being the official ‘discoverer’ of the species. Rothchild won that battle and a man called Buller lost.
While people were excited about discovering a new species of bird, 17 people at the lighthouse were letting their unfixed (neither spayed nor neutered) cats wander around the island.
Ultimately in 1905 a correspondent in a newspaper writes:
“And we certainly think that it would be as well if the Marine Department, in sending lighthouse keepers to isolated islands where interesting specimens of native birds are known or believed to exist, were to see that they are not allowed to take any cats with them, even if mouse-traps have to be furnished at the cost of the state.”
Stephen’s Island is tiny: The island is 1.5 square kilometres (0.58 square miles) in size. This made the bird even more vulnerable.
Island Species Extinctions
The feral cat is often criticised for what might be called ‘island extinctions’. This is the extinction of wild animal species on small islands where they are ‘captive’ and where cats can do a lot of harm to their population and even make them extinct if the species only exists on the island (‘island species’).
Island species account for 83% of all documented extinctions. They are very vulnerable. However, exaggerated claims are made about feral cats making these species extinct. I would not completely trust the internet to provide accurate information on this subject unless you can reassure yourself as to the author. This is because there are a lot of people with hidden agendas (e.g. to see feral cats exterminated) pushing their ideas onto people.
Scientists say that feral cats have caused the extinction of 15 island species BUT other predators such as foxes, cane toads, mongooses and especially rats can be at least as devastating or more so to island species.
And sometimes the presence of cats can be beneficial to island species. For instance on Stewart Island (off the coast of New Zealand) the kakapo, a flightless bird, has lived side by side with feral cats for 200 years. The cats feed on rats introduced by people. Rats have been implicated in the extinction of several species of bird in the same area. Removing the cats might lead to an increase in the number of rats which in turn could lead to the extinction of the kakapo.
When researching predation of species by feral cats I’d advise caution and the use of books by respected authors. By all means use websites but check and be skeptical.
Sources: Stephens Island Wren – Wikipedia (the author researched this very well). Island extinctions – Dr Bradshaw Cat Sense (a respected author on the domestic and feral cat).
Picture of the island: By LawrieM – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=16487913). I have lightened the photo as it was 2 stops too dark.
[weaver_breadcrumbs class=’alt-class’ style=’inline-style’]