New Zealanders play cuckoo to the last ten black robins on earth
Auckland, New Zealand — Per capita, the Chatham Island black robins receive quite a bit of attention. Only 10 of the creatures remain - making them one of the rarest birds in the world - and attempts to bring them back from the brink of extinction have required a great deal of human ingenuity.
Since 1980, the New Zealand Wildlife Service has relocated the birds once, found two different sets of foster parents for their eggs, and hauled shrubbery 1,000 miles so the birds could live in a familiar bush.
The trouble with nonmigratory birds in New Zealand, such as black robins, is that until Europeans introduced predators, life was too easy.
Others birds accustomed to a predatory environment breed with haste and produce big clutches. The black robin, however, ignorant of cats and weasels until 150 years ago, continues to breed at a plod.
Until 1980, the robins shared Little Mangere Island at the southern end of the Chatham Islands group with a seabird known as the muttonbird. Muttonbirds nest in burrows and their young have the misfortune to be considered a delicacy. Poachers slashed down local shrubs, the akeake, to get at muttonbird burrows. For the robins this spelled disaster; the akeake provides the environment robins demand. By 1980, the robins had dwindled to seven.
Enter Don Merton, the wildlife officer overseeing New Zealand's endangered birds. He arranged to have 120,000 akeake seedlings flown from 1,000 miles north of New Zealand to the Chathams. The seedlings and the last seven robins were landed through the surf on a new island which had been picked as a better home for the robins. That winter two died, leaving only two breeding pairs and one celibate hen.
Then the resourceful Mr. Merton tried to force the robins to breed faster. He stole the eggs from their nests during the 1980 season and switched them to Chatham Islands warbler nests.
The robin hens each laid more eggs to make up for the loss, and the warblers raised no objection to having Merton play cuckoo with them. But warblers were not ideal foster parents. Their own chicks' nurturing time is briefer than for robins, and the warblers did not nurse their robin nestlings through to maturity.
The next best prospect as foster parents was the Chatham tomtit. The tomtit lived on yet another island, on the edge of the sub-Antarctic storm belt. There the Wildlife Service took the robin eggs, and the tomtits proved ideal.