SOME ASPECTS OF INCUBATION IN THE MANX SHEARWATER PROCELLARIA PUFFINUS, WITH PARTICULAR REFERENCE TO CHILLING RESISTANCE IN THE EMBRYO

摘要: Summary. 1. Large-scale excavations and observations during homing experiments provided incidental data on incubation. 2. The main period (median 90%) of egg-laying is from 25 April to 20 May, hatching 17 June 12 July. median dates for these processes are 6 May 28 June. average incubation 53 days. 3. Incubation shifts long (average 5 days) variable, 2 16 days if unrelieved. Temporarily deserted eggs were only found in about 1% undisturbed nests. 4. Nevertheless many well-developed hatched after being chilled the burrow up 7 days. Others remained viable 13 laboratory. length chilling stage development at which it occurs have little effect proportion surviving. 5. ecological evolutionary significance faculty considered, with a brief survey resistance embryos other birds.