Something I was wondering. When birds breathe, do their airsacs contract and expand like the lungs do?

Also, if they do, do they contract and expand as much as the lungs do?

Thanks so much!

  • $\begingroup$ This borders on a homework question, have you tried googling avian respiration. people.eku.edu/ritchisong/birdrespiration.html $\endgroup$
    – John
    Jan 28, 2021 at 16:21
  • $\begingroup$ @John Yes. I watched several videos on the subject and read several pages. One mentioned the lungs contracting and expanding slightly, but none said anything about the air sacs. $\endgroup$ Jan 30, 2021 at 1:12

1 Answer 1


They move air in and out of their lungs and air sacs by means of special muscles that move the ribs and sternum downward and forward, expanding the body cavity and causing inspiration, and then up and backward, contracting the body cavity and causing expiration.

  • $\begingroup$ Thanks Jitendra Singh! I would've upvoted your answer, but I can't right now. $\endgroup$ Jan 29, 2021 at 0:04
  • $\begingroup$ @ArchduchessFerdinand I guess below the upvote button you would have the tick button. If you like my answer then click on that button and wait till it becomes green. Actually, this would mean you have accepted my answer. If you havve any problem you can write in comment $\endgroup$
    – user63862
    Jan 29, 2021 at 5:14
  • $\begingroup$ I was told I'm meant to wait two days before accepting an answer, sorry. $\endgroup$ Jan 29, 2021 at 6:40

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