Stephens Island wren

Stephens Island wren

The New Zealand wrens are an ancient family of tiny birds with no close affinity to other groups of birds. They arrived in New Zealand at the same time as the New Zealand thrush and the wattlebirds, wind assisted migrants in early Cenozoic times. They have short, rounded wings and a very short tail. Females are larger than males. The history of the Stephens Island wren, so far as human contact is concerned, begins and ends with the exploits of a domestic cat, so the ornithologist W.R.B.Oliver relates.

In 1894 the lightkeepers’s cat on Stephens Island brought in eleven specimens which came into the hands of a H.H. Travers. Ten were forwarded to Rothschild and one to Buller and each recipient described the species under a different name. A few more captures were made and duly reported by the cat and then no more birds were brought in. It is evident, Oliver says, therefore, that the cat which discovered the species also immediately exterminated it. Incidentally, the lightkeeper was a man called Lyall who gave his name to the bird.

Oliver goes on to describe the bird: upper surface dark olive with brown margins to the feathers, giving a mottled appearance; wings at flexure olivaceous yellow; quills and tail olivaceous brown. Narrow superciliary streak, throat, foreneck and breast olivaceous yellow with dark margins to the feathers; abdomen and sides of body olivaceous brown. Bill dark brown, feet dark brown. Bill 14, wing 46–49, tail 17, tarsus 19–20, mid toe 20–21mm.

Oliver says, finally, that the only information concerning the habits of this species that has been recorded is that it was semi–noctural and lived among rocks, running about and hiding, but it was never seen to fly. It was presumably insectivorous, like its relatives.

Another aspect of the story is related by Dr Richard Holdaway in the New Zealand Geographic, 1996: “the surveyors and workmen who stepped ashore on Stephens Island in the 1890s to build the light station stepped back in time. The tiny island held the last fragment of “mainland” New Zealand as it was before humans arrived in the archipelago. Not even the Pacific rat, the Kiore, introduced by Maori, had reached the island. Small as it was, the island’s forested summit held a diversity of vertebrates and invertebrates that even then was unique.

The wren population on Stephens Island was, in fact, the last remnant of a species that once lived throughout New Zealand. It was the third of the six known species of New Zealand wrens to become extinct. Thought to be the only flightless songbird in the world to be seen by Europeans, the Stephens Island wren was swept from the mainland by the Pacific rats that exterminated its two flightless relatives — the thick–thighed and long–billed wrens — hundreds of years before. The fourth species to go was the bush wren. Another island reserve, kept almost as pristine as a muttonbird island, was its last outpost. Black rats went ashore from fishing boats and finished them off in the 1960s. Only the rock wren and rifleman survive.”