Alarm over dwindling kereru

Forest and Bird, Volume 23, Issue 2, 1 May 1992, Page 5

Alarm over dwindling kereru

Source:

Northern Advocate

NEW ZEALAND’S native pigeon, the kereru or kukupa, could soon be extinct in Northland, jeopardising the ecology of many forests, according to Department of Conservation scientist Ray Prctce, Dr Pierce, of Whangarei, has grave fears for the future of Northland’s pigeons and says they could disappear within 40 years if action is not taken now.

Native pigeons are vital for the dispersal of seeds from the puriri, taraire, karaka and tawa which dominate most Northland forests and without them the forests would go into decline. The bird’s status is about to be "upgraded" to threatened, and Pierce says it’s not a moment too soon. He has studied 17 pigeon nests in Northland this summer and found that only five pairs managed to raise young. The others laid eggs but they did not hatch, largely because of predation by stoats and rats. Native pigeons were common throughout New Zealand 40 years ago. Most people think they are still common, but Pierce says research tells a different story. He believes New Zealand is

heading for a second wave of species extinction. Robins, parakeets, yellowheads, kakariki and even kiwi are under threat, he says. "These are birds which people think are common. But they’re not anymore. Forty years ago there were hundreds of kaka in Waipoua forest too and now they are totally gone from Northland. It only took 40 years for them to become extinct and I beheve we could be looking at the same time frame for kereru." Pierce is particularly concerned about the pigeons because of their pivotal role in forest ecology. "Since the disappearance of the moa they are the only birds which disperse seeds from the taraire and puriri. Without them the forest will be threatened." Scientists are still in the process of collecting information on what is happening to the birds, but Pierce believes predation by stoats and rats and competition for food from possums are major factors. All adult birds should be able to breed successfully every season, but few manage to raise young. There was evidence in many of the nests he studied that predators had eaten the eggs. He intends analysing a hair found on one nest to see what type of animal it came from. Two of the five pairs which managed to raise young were nesting in trees which had metal sheets wrapped around their trunks to stop stoats and rats climbing them. There were also indications that birds nesting in urban areas had more success in raising young, possibly because dogs and cats controlled the number of treeclimbing predators. "One of the few successful nests had two cats and a rottweiler

camped at the base of the tree," said Pierce. Dr Pierce intends to monitor adult birds for the next year by attaching radio transmitters to them. He hopes to build up a picture of what is happening to the birds so a rescue plan can be drawn

up and put in action. Northland is one of the main strongholds of the pigeon because of its abundant food supplies. "If we can’t save them here we can’t save them anywhere."