Status of weka (Gallirallus australis greyi) on Mokoia Island

The status of weka on Mokoia Island was assessed in two ways: (1) by surveying the number of weka on the island using two methods: call broadcast and unsolicited call survey, and (2) by capturing weka. Using our call broadcast technique we have estimated the population of weka on the island between 90 and 120 birds. However, several areas of the island were not surveyed. We caught 12 birds in 19 days (1420.5 cage/hrs). This catching success was low when compared to Owen 1998 (34 birds caught in 10 days). A possible explanation could be the availability of a great variety of foods at this time of the year compared with August, when Owen and collaborators were catching. We recommend that a monitoring programme for weka is established on Mokoia well in advance of mice eradication (currently scheduled for 2001) to allow the Department of Conservation to effectively measure the effect of the poisoning on the birds. Removing some weka, as was done prior to the first attempt to eradicate mice, is also recommended. Future studies of weka on Mokoia considered necessary include: feeding studies (food availability and use/preference), importance of habitat structure for weka, and breeding dynamics.