Notes on the Nesting Biology and Diet of Victoria's RiflebirdPtiloris victoriae

Abstract

An inaccessible Victoria's Riflebird Ptiloris victoriae nest containing two nestlings.was watched for 6.5 h over three days before the young fledged. A second, accessible, nest was intensively studied by video-surveillance and direct observation. This nest was typical of the species but snake skin ‘decoration’ was not added until several days after egg-laying. The naked, dark-skinned, nestlings were typical of birds of paradise. At the second nest 128.5 h of incubation activity was recorded; the two egg clutch was laid on consecutive days, incubation started with the first egg, and both hatched between 0830–1030 h on the same day after 18 and 19 days incubation. Only the individually identifiable, presumed female, parent attended the nest and spent 71% of time incubating (average bout 44 min; average absence 18 min; 1.0 bout per hour). One nestling died at three, and the other left the nest at 14 days old. Rapid nestling growth and development is described and illustrated. Parental care of the nestling(s) was recorded for 148.5 h (mean = 8.5 h per day). Most (68%) of 242 nestling meals consisted of a single item brought in the parent's bill, 26% also involved food being regurgitated and 6% involved meals entirely regurgitated. A total of 256 nestling meals involved 280 items of which 78 to 89% were animal and 11% fruits. The results of this study are compared with what little is known of the nesting biology of other birds of paradise.