Official journal of the Netherlands Ornithologists' Union
|Hockey P.A.R. (1984) Growth and energetics of the African Black Oystercatcher Haematopus moquini. ARDEA 72 (1): 111-117|
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African Black Oystercatchers fledge at 35-40 days, being significantly smaller than adults in all dimensions except tarsal length. Maximum growth rate (15.6 g per day) occurs between 15 and 31 days and is less than predicted by Drent & Daan (1980) for subprecocial seabirds. Within the Charadriiformes, it appears that a colonial or territorial breeding strategy influences the age and size at fledging: territorial birds fledge small and early whereas colonial breeders normally fledge large and late. Early fledging is probably adaptive as an anti-predator strategy in territorial species. Daily energy intake of African Black Oystercatcher chicks peaked at, or immediately prior to, fledging. Daily existence energy of nonbreeding adult African Black Oystercatchers was calculated, based on a knowledge of ME and activity budget, at 629 kJ, 2.47 x BMR: this is close to the value predicted by Walsberg (1980). The gross annual energy removal by one pair of birds laying two eggs and rearing one chick was estimated at 537,733 kJ (Table 4). The mean assimilation efficiency of a growing chick was 72%, and of a fledged subadult was 73% (Table 3).