An illustration of Stephens Island Wrens by John Gerrard Keulemans Public Domain Outdoor cats have gotten something of a bad rap lately — and not without reason.

Recent research suggests that domestic cats kill billions of birds and other small animals every year, and could even pose a significant threat to local wildlife populations.

It's a hot-button issue today for conservationists and wildlife enthusiasts, but in fact cats and wildlife have been at odds for decades — one striking example is the battle between Tibbles the cat and the Stephens Island Wren, a battle that ended with the wren's total extinction.

Tibbles lived more than a hundred years ago on Stephens Island, a small island off the southern coast of New Zealand, where her owner, David Lyall, was one of the lighthouse keepers. The wren lived there, too.

A mysterious little animal, small enough to fit in the palm of your hand, the Stephens Island wren was believed to be nocturnal and flightless, much like the highly endangered kiwi bird that still roams New Zealand. It probably scurried along the ground gobbling up insects, as other surviving species of New Zealand wrens do today.

The Stephens Island wren wasn't always confined to Stephens Island. The fossil record shows that this little bird once roamed all of New Zealand.

But by 1894 invasive species brought by Europeans had all but wiped it out, except on Stephens Island.

1894 also happens to be the year Lyall and Tibbles moved to the island.

Stephens Island Wikimedia Commons Legend has it that shortly after establishing themselves on the island, Tibbles started bringing dead wrens to her owner as presents, many of their bodies still in good condition despite having been killed by the cat. These little birdies didn't die naturally.

Being interested in natural history, Lyall sent specimens off to England, where they fell into the hands of several naturalists, including Sir Walter Buller, an bird expert.

Buller recognized the bird as a new species of wren and reported the discovery to the British Ornithologists' Union — but, alas, it was too late for the Stephens Island Wren.

Legend goes that the little birds' population was so decimated by Tibbles' hunting habits that the whole species went extinct within a year of its discovery.

Not everyone blames Tibbles, though. It's possible that the story of the Stephens Island wren is more complicated than the legend makes it out to be.

In a 2004 essay published by the Ornithological Society of New Zealand, Ross Galbreath and Derek Brown argue that the wren's extinction may have been spread out over a slightly longer period of time — historical documents suggest that a few more specimens may have trickled in over the next two or three years.

Galbreath and Brown also write that there may have been more than one cat on the island, although records are unclear on this point.

However, it's uncontested that cat predation was the nail in the coffin for the now-extinct Stephens Island wren. And Tibbles, whether she actually worked alone or not, has become the poster cat for the dangers posed by outdoor cats.

Meanwhile, preserved specimens of the Stephens Island wren now reside in natural history museums in both Britain and America — sad, stuffed reminders that small changes in an ecosystem can lead to very big consequences.