Growth and Development of Homeothermy in Nestlings of Eurasian Spoonbill (Platalea eucorodia)

Body mass (BM),body length (BL),wing length,tarsus length,and body temperature (Tb) of 13 nestlings of Platalea leucorodia at Zhalong Natural Reserve (47°29′N,124°02′E) were measured every two days in a period from April to June in 1994 and 1995.The growth of the nestlings was in keeping with the logistic equation,and the highest relative growth rate appeared in the period of 4-8 days.Tb steadily increased with age in days and not fluctuated with ambient temperature (Ta),and the extent of reduction in Tb after cold exposure of 25 min to Ta progressively decreased.Nestlings within first 28 days,BM was positively corrected with Tb in nests and after cold exposure,and BM and BL were also positively related to the index of homeothermy.This means that body growth is in synchronization with thermogenic ability,reflecting the character of altricial nestlings.