Posted: 08/05/2013 at 21:39
Hi, re the duck eggs, the female will keep laying until she has enough for a brood - she won't start sitting until then - that way they will all start developing at the same time and hatch at the same time.
If she started sitting when she started laying (as birds of prey and owls do) the chicks would hatch at intervals - this is a good strategy for them as in times when prey is scarce the older chicks will cannibalise the younger 
- whereas with ducks they all need to hatch out at the same time so the mother can take them all to the nearest water. 
