Research on New Zealand dotterels during the 1994-95 season

STEWART ISLAND There were problems obtaining suitable baits for the Table Hill cat-control operation this season. The Landcare-ACP baits supplied initially were late, in very poor condition on arrival, and were unsuited to the task. Dupont baits from last season were used for two changes, while awaiting a supply of new Dupont baits. Reliable supply of a suitable bait is pivotal to the whole programme , and is a problem that must be addressed urgently. By the end of the season only one male-female pair of dotterels remained on Table Hill; they fledged two chicks. Other birds appear to be establishing on Table Hill and will probably breed there next season. There were no opportunities to carry out egg manipulations on Table Hill this season. Annual flock counts showed that the population had risen to about 75 birds in late March 1995; during the season there were losses of banded adults but this was offset by high productivity overall. It is recommended that the cat-control programme continue and that some survey work is undertaken to update our knowledge of dotterel breeding distribution on the island. NEST-CAGE TRIALS Trials were undertaken in the North Island to test the possibility that mesh cages over nests may afford protection from cats to eggs and incubating adults. It proved surprisingly difficult to find a size of access hole that allowed dot-terels easy passage to their nests but excluded cats. Dotterels entered cages over their nests and continued incubation, and no longer-term adverse effects were noted. No opportunities arose on Stewart Island this season to test nest cages. It is recommended that development of the cages continue in the North Island and that cages also be tested on Stewart Island during the 1995-96 season. CAPTIVE-REARING Captive-rearing trials were undertaken in the North Island. Between early October and late December 1994, 40 eggs were collected from sites in North Auckland, Coromandel and Bay of Plenty and transferred to Otorohanga and Auckland Zoos for incubation and rearing. There were a number of early deaths (in shell, during hatching and in the week after hatching), possibly caused by sub-optimal incubation conditions. There is to be a meeting of those involved in the programme to discuss ways in which hatching and survival can be increased. 1 Thirteen birds survived and were released. Eight were released at Omaha Spit in early February 1995; all disappeared rapidly, with some killed by …