Black robins fewer

Press, 6 December 1989, Page 28

Black robins fewer

PA Wellington The Chatham Islands black robin population has declined about 15 per cent since March, the Conservation Department’s endangered species conservation officer, Mr Ron Nelson, said.

After a two month monitoring stint on the islands, Mr Nelson said 77 black robins had survived the winter.

Winter could be tough for small birds on the Chathams, he said. The deciduous ribbonwood is the forest canopy, giving little shelter from cold snaps or inward-fly-ing big sea birds. Mr Nelson said the world’s rarest bird had been intensively managed for the last five years. The department had now decided to “take a

step backwards and monitor what happens to the natural population.” Breeding pair and population numbers and the movements of each bird would be monitored. In 1980, only five black robins remained on the 1 Chathams, the world’s 1 only black robin habitat. This group included only one breeding pair.

Mr Nelson said there were now 34 breeding pairs although, as many of these were young birds, their success rate this season would not be high. Young black robin mothers have a high nest desertion rate. The Chathams black robin is probably the only bird species in the world where the genealogy of each individual was known as all the existing birds descend from Old

Blue, he said. Old Blue, now dead, has been credited with saving , the black robin' from extinction by changing to a younger mate with whom she successfully paired. All eggs she had produced with her former partner had been infertile. Each black robin had been colour-coded and named by Conservation Department staff. Mr Nelson said this and the known genealogy made the species extremely valuable for scientific research. The staff would continue colour banding this breeding season. Each bird must be banded at 15 days of age, he said. The department wbuld re-evaluate the monitoring programme in a year, Mr Nelson said.