h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Most of what is going on today (the important bit) is described at http://chickscope.beckman.uiuc.edu/explore/embryology/day21/hatching.html The times in that article are averages--it can take up to 24 hours from pip to zip, at one end of the scale. At the other... I went to the store to get some cold medicine. When I left, there were no external pips. Half an hour or so later, I get a call--a beak is visible! Half an hour after that, I arrive home to the news that the chick is hatched

I've gotten the pen ready for Frieda and the chicks--the plan has always been to have her raise the chicks, as she's done well in the past, and has adopted chicks with no problems before. All that's left is to fill the waterers I've washed and hang them, one at chick height, and one at Frieda height. When chicks first hatch, they are still subsisting on the yolk, and will be for 72 hours, so it won't hurt the incubator chicks any to wait until I've moved Frieda and any she hatches into the pen.

I had had plans to meet friends to watch The Princess Bride tonight, but that's been cancelled on account of illness on the part of the organizer. I can see myself parked in front of the incubator, especially since I'd already planned for dinner tonight to be something simple

What does "subsisting on the yolk mean"? Is it a puddle of yolk that they dip into?

Not quite... Think of the yolk as an extra, food-filled stomach--a holding bag, sort of. Throughout incubation, the yolk is what fuels growth and development. There's enough left over at hatch to last the chick up to 3 days, to allow it to hang out under mom while she stays clamped down over unhatched eggs. If a chick had to eat right away, the hen would have to either abandon her remaining eggs when the first chick hatches, or let the first chick starve to let the most eggs possible hatch over the next day or so.

Ah, so the process is still similar to what it is when the chick is inside the egg, I see