Black Robin: Back from the Brink of Extinction
This week no apologies for bringing you a success story which although enacted through the 1970s and 1980s still manages to amaze and awe. I'm talking about the rescue of the black robin from the brink of extinction by the NZ Wildlife Service team led by Don Merton. The still images come from the NHNZ classic film Black Robin a Chatham Island Story (1990) - itself a compilation of three documentaries, Black Robin, Seven Black Robins and The Robin's Return which were made during those decades and which were the founding films upon which the formation of NHNZ (formerly TVNZ's Natural History Unit) was based.
"When Europeans first arrived on the Chatham Islands the black robin (Petroica traversi) was relatively widespread. But in the all too familiar pattern, its numbers dwindled as European settlement progressed. By late last century it had become restricted to a bleak pocket-handkerchief of stunted forest on top of Little Mangere Island. Here it struggled with its impoverished habitat, until by 1972 there were only 18 individuals left. Just three years later the numbers had dropped to nine. The black robin, it seemed, was facing certain extinction.
In 1976 a team from the Wildlife Service led by Don Merton launched a daring and remarkable rescue attempt.
Because the scrubby forest atop Little Mangere was deteriorating it was first decided to move the birds to nearby Mangere Island. It was a risky decision, since the bird's numbers then stood at seven, of which only two were female. Any mistake would finish the species.
The difficult transfer was a success and the birds settled in to breed in their new home. Births, however, did not keep pace with deaths and by 1979 the population was down to five. In a final desperate bid to boost numbers it was decided to try cross fostering, a technique never before attempted in an endangered passerine population in the wild. This involved taking eggs from robins and putting them into the nest of another species that would serve as a foster parent. The robins, having lost their first clutch, lay a second one, hence doubling the number of young produced each year.
The first foster parent tried, the friendly Chatham Island warbler, managed to raise the black robin chicks with only limited success. Therefore it was resolved to try the more closely related tomtit instead. This meant transferring the eggs 15 kilometres by sea to South East Island, where the tomtits lived - yet another hazardous journey. This idea proved the breakthrough that had been hoped for.
The tomtits were model foster parents and in 1983 a second population of black robins was established on South East Island.
Breeding success was so good that within three seasons there were 38 black robins. By late 1988 numbers had topped the hundred. The black robin was at last out of danger."
The text has been taken from 'Natural History of New Zealand' by Nic Bishop, Hodder & Stoughton, 1992 (ISBN: 0340548029) - and if you'd care to read a fuller account I suggest 'Wild South: Saving New Zealand's Endangered Birds' by Rod Morris & Hal Smith, TVNZ in association with Century Hutchison, 1988 (ISBN: 090869038X)And for futher information about the current conservation work by the Department of Conservation (formerly NZ Wildlife Service) check out their website.
If you'd like stock footage of the black robin, or many other endangered New Zealand wildlife (or for that matter wildlife endangered or not from around the world) then please check out our on-line catalogue at NHNZ Images or send us an email.