Body-maintenance activities of the South Island Robin

Abstract

Descriptions are given of each of the body-maintenance activities of the South Island Robin Petroica australis australis. The activities are stretching, body-shaking, head-scratching, beak-wiping, toe-nibbling, preening, bathing, anting and sunning.

On average Robins took 1.4 minutes to bathe and 3.0 minutes to dry off afterwards; in all, 0.5% of their time was spent bathing and drying. They bathed at a similar frequency in each period of the day.

Most Robins anted on the ground using ants or millipedes. Of the thirty-two bouts observed, twenty-five consisted of birds finding an animal, anting with it for a few seconds and then eating it. During the other seven bouts several animals were used successively. In total, Robins spent 0.04% of their time anting. Anting was probably a feeding move- ment for removing and/or avoiding the defensive secretions of some prey species.

Adult Robins sun-bathed mainly in December to February inclusive, when they had completed breeding and showed no signs of moult, or had begun to moult. The mean duration of sunning exposures was 2.1 minutes, with an average of 2.6 exposures per bout. Sunning did not seem to be essential because immatures did not sun-bathe and adults sunbathed much less than expected.