Growth of nestling Hamerkops Scopus umbretta in central Mali

Abstract

Data on growth of nestling Hamerkops Scopus umbretto were analysed with respect to year and season of hatching and to hatch sequence. Quantitative growth characters included weight, culmen, tarsus, tail, third outermost primary quill, standard wing-length and wing span. The growth constant K of weight was 0179 and time tI0-tw was 21.8 days. Least-squares analyses showed differences in weight gain, culmenlength and tarsus-length related to year and month but not to sequence of hatching. Predictive equations for character against age are provided for all linear measurements. Characters which attained apparent asymptotes before fledging were weight and culmen and tarsus-length whilst other characters varied between 80 and 90% of reported adult size. Qualitative indications of growth discussed are crest development, colouration and the disappearance of the egg-tooth. The rainy and post-rains seasons appear to offer the Hamerkop the best chances of successful breeding and maximum growth rates.