First breath

[Daidohead]

At what point does a chick need to breathe air ? What is the mechanism that makes the change happen ?

 

[Bring]

I have no idea but.....
There is an air sac inside the egg. I've also heard people say they can hear the chicks cheeping before they even pip so that makes me Wonder if they have to push air past their vocal chords or whatever to make sound. Interesting question.

 

[The Wolf Queen]

They need air when they internally pip into the air sack then when that air starts to run out they externally pip. Sorry I cant be of more help

 

[Daidohead]

The air sac isn't large enough to sustain a chick for very long, and with their metobolic rate I am very curious as to where and when they get the air they need. I know an egg shell is porous enough to allow an exchange of gasses, but porous enough to breathe through ?

 

[mulia24]

generally, all beings (except some anaerob bacteria) need oxygen (breath) to keep alive, if they don't breath, they'll die.

that apply too for chick.

 

[Ariel301]

The chick's lungs are not functioning and it is not breathing until after it pips internally into the air cell. It is just like a mammal or human baby inside the uterus, it does not breathe until it gets out. The oxygen is supplied directly to the blood through the placenta and umbilical cord and completely bypasses the lungs. The chick will breathe the air that is inside the air cell once it is pipped into that, and it is theorized that the rising level of carbon dioxide in there is what causes muscle spasms which cause the chick to break its shell to find air. I assume there is some gas exchange through the shell, as it is porous, but it would not be enough that the chick could live in there like that indefinitely, it has to come out for fresher air eventually--like you sitting inside a closed box with just a few tiny airholes, eventually you're going to get pretty uncomfortable.

 

[Daidohead]

Quote:
Thank you, I hadn't considered carbon dioxide as a possible trigger. That may also explain how the chicks cheep inside the egg. If they have broken into the air cell they have enough air to produce sound while they are still getting their oxygen from their umbilical supply.