Artificial incubation of Maleo Macrocephalon maleo eggs at the Bronx Zoo/Wildlife Conservation Society, New York



Megapodes are characterized by using means other than body heat to incubate their eggs. The Maleo Macrocephalon maleo is endemic to Sulawesi where it is Endangered, and lays its eggs in pits excavated in soil heated by geothermal sources. A novel method used to incubate Maleo eggs at the Bronx Zoo/Wildlife Conservation Society, NY, USA, is reported here. Using a forced-air hatcher, the eggs rest on a bed of plastic beads inside a plastic container. Incubation parameters were 32·5°C and 89–90% relative humidity, with an 83% hatch success after an incubation period of c. 70 days. A strong correlation was found between higher incubation temperature and shorter incubation period. The eggs lost an average of 21% of their initial weight between evaporation through the shell during incubation and the liquid discharged from the egg at hatching. The rate of weight loss changed during incubation, starting very slowly and increasing dramatically at the end of the period. Further studies should investigate the effects of humidity on hatchability and survival of chicks, the effect of temperature on the sex ratio of hatchings, as well as the effect of the orientation of the egg during incubation on hatchability.