egg laying time

[crpntr@ix.netcom.com (Kenneth Carpenter )]

The following on egg laying and incubation is from Bertram, B. 19992, 
The Ostrich communial nesting system. Princeton University Press. 196p.

Ostriches lay at 2-3 day intervals, as does the Rhea (no data for other 
ratites). Incubation does not begin until after ~16 eggs are laid by 
the ostrich (i.e., 32-38 days), but sometimes later if potential 
predation is low. As a result, the eggs undergo considerable daily 
temperature fluctuation (20C-40C) until incubation begins (stable 
temperature of 36C). Egg hatching is synchronized by controlling the 
temperature of individual eggs, i.e., slowed by pushing them away from 
the parent (heat source) and sped up by keeping them closer to the 
parent. Thus, eggs laid 32+ days appart will still hatch within two 
days of one another.

Kenneth Carpenter
Dept. of Earth Sciences
Denver Museum of Natural History
2001 Colorado Blvd.
Denver, CO 80205
crpntr@ix.netcom.com