Egglaying/incubating/hatching process - many questions!

[jbtweed]

Hi there guys,
this may seem like a really silly question, but I really have no idea! Recently, we had a hen sitting on 15 eggs in a lavender bush (technically they're meant to be in their 1/4 acre run, however, they've decided they'd rather be free range chickens and turn our garden soil for us). What I don't understand is this - the incubation period lasts 21 days, but they all (14 of 15!) hatched on the same day. When the hen lays the eggs, does she lay them one day at a time, or all at once? How does that work?

Also, we just yesterday had a little white hen with fluffy feet (really not sure about breeds - she's adorable though) hatch 7 eggs. Four are black, two are bright yellow, and one is completely ginger, with a bit of a black stripe across it's head. How does it happen that we have such a variation of chicks from one clutch of eggs? (Also, we know that all the eggs are her eggs.)

 

[Ridgerunner]

The hen lays them one per day. They do not start to develop until she starts incubating them.

Hens seem to love laying in other hen's nests and a broody chicken will try to hatch any egg in her nest. It is certainly not limited to the ones she lays. If you are certain that all the eggs were hers, then one possibility is that both she and the rooster are not purebreeds, at least as far as colors go. Some colors and patterns are dominant over some but recessive to others. It is not one color gene that determines colors and patterns but a combination of several. You don't mention what color your rooster is, but I'd suspect black is in the mix.

Another possibility is that you have more than one rooster, so the chicks have different fathers.

A combination of more than one rooster along with a hen with recessive genes would easily explain this.