Use of supplementary feeding to induce breeding in free-living kakapo Strigops habroptilus in New Zealand

Published source details Powlesland R.G. & Lloyd B.D. (1994) Use of supplementary feeding to induce breeding in free-living kakapo Strigops habroptilus in New Zealand. Biological Conservation, 69, 97-106.
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Summary

Commencing September 1989 (at least 11 of the 22 kakapo known to be alive), some preferred foods (apple Malus domestica, sweet potato Ipomoea batatas, sunflower Helianthus annuus seeds and nut kernels) were eventually provided each night at up to 12 feeding stations.

After several trials, feeding station design comprised a tray (5 cm deep x 30 cm diameter) 35 cm above ground on a 2.5 cm diameter aluminum tube, with a black plastic dust-bin lid 15 cm above the tray to keep out rain. A hinged lid was added (which kakapo had to lift up to access the food), to further exclude Pacific rats (kiore) Rattus exulans and keep out the damp (in cloud forest areas). To improve hygiene, a piece of plywood (40 × 30 cm), was placed under each station and food on the ground regularly removed.

Kakapo use at five stations was observed from small hides. All known track-and-bowl systems (where males 'boom' to attract females) were inspected regularly in the 1989-90 and 1990-91 breeding seasons, and females radio-tracked to assess breeding status.

Kakapo regularly used the feeding stations, but least in summer when male breeding activity peaked and females were mating or nesting. Females nested on Little Barrier for the first time in summer 1989-90. Two of the four (radio-tagged) females had nests but both failed: one hatched a single egg in February but the chick died; the second was incubating at least one egg in March but it was abandoned.

In the 1990-91 breeding season, the four radio-tagged females had been taking supplementary food for at least 11 months, plus a fifth female for an unknown period. Four nested. Two nests failed: one contained an infertile egg, the other one infertile and one fertile egg (the embryo died). A third female laid two eggs in late January. One was removed for hand-rearing; the resultant chick died at four days old due to infections. The other hatched and the chick was successfully raised. The fourth female laid three eggs in January, two hatched. One chick of about 30 days disappeared in March. The other fledged and was observed at a feeding station with its mother in September 1991.

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