In 1894, ornithologists came to know of the existence of a small flightless bird on Stephens Island in New Zealand.
It was named Stephens Island Wren. The bird was only 10 cm long and was never seen to fly. It would scurry like a mouse on the ground.
There was a lighthouse there and the lighthouse keeper had a cat named Tibbles.
Tibbles found the birds easy prey. In the space of a few months, it killed all the birds on the mile-long island, making the Stephens Island Wren extinct in the very year that it was discovered.
If it were alive it would have been the world's smallest flightless bird. Now that distinction goes to the Inaccessible Island Rail which is about the size of a newly-hatched domestic chicken.