Notes on Black Crakes Amaurornis flavirostra 1: Breeding, plumages, and social structure

Abstract

Records from a family of Black Crakes on a small dam include 16 nestings between September 1985 and February 1995, with results from laying to disappearance of fledged young tabulated. Successionally downy hatchling, juvenile, immature, and adult plumages are described with timing. Unexpectedly, there appeared to be two alternate plumages—‘grey’ or ‘sooty’—in the third immature stage, with a possibility of the latter having previously been mistaken as a ‘non-breeding’ adult dress. Need for further research to confirm is stressed. Moults from ‘breeding’ plumage directly into new ‘breeding’ plumage were observed, but no moult from a ‘breeding’ into a ‘non-breeding’ dress was seen. Juveniles and immatures helped care for the young of up to four subsequent clutches, the fluctuating family membership contained between one and seven age classes and a maximum of 12 individuals on two occasions.

Keywords: Co-operative breeding, plumages