Spyke
anon6789
lemmy.world

Some helpful info from Dana Williams :

The question arose last night in chat about how an owlet, or any great horned owl, can swallow a large food item without choking, ie. a whole mouse or a rabbit foot.

This is possible because the GHO glottis [the opening to the respiratory tract] is closed off reflexively when the owlet/owl takes in a food item. The red arrow in the first picture points to the glottis in a GHO.

At the time the glottis is closed air can still be taken into an owl's respiratory tract thru the nostrils, to the air sacks in the head and into the respiratory system as a whole. See the second photo.

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anon6789reply
lemmy.world

I'm going to have to dive into this further at some point. I knew the air sacs existed, but not how they worked. From some more quick reading, birds breathe very differently than we do.

BirdFact

The avian respiratory cycle can be described in four stages, or two inspirations and two expirations, which is very different from our two-stage tidal respiration pathway. Here’s how it works:

When birds inhale, air collects in the posterior air sacs below and behind the lungs. This oxygenated air only enters the lungs when they exhale, and that’s when the bulk of gas exchange occurs. On the next inspiration, deoxygenated air leaves the lungs and enters the anterior air sacs. Finally, air is expelled through the beak on the second exhalation.

Mika Steele

The Great Horned Owl gets oxygen by in taking through its mouth. In addition to lungs, owls also have air sacs. Air sacs are vital for these owls. When owls fly, they burn a lot of calories, so they have to take in a lot of air. The air sacs act as extra room to store oxygen. Oxygen enters the blood through diffusion this is when the cells diffuse so molecules move from higher concentration to lower concentration. Because birds don't have diaphragms, air is moved in and out through pressure changes in the air sacs. Unlike mammals, the owl's lungs to not expand and contract. Birds exhale carbon dioxide, like all other animals.

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lemmingreply
sh.itjust.works

If you ever get a fresh whole chicken (for dinner, for example), you can remove the breasts, then carefully remove the ribcage, make a small hole in the trachea, insert a straw and blow into it, you can inflate the sacs. Even if you know they are there, it's still quite surprising. They are big! Highly recommend, if you're up to such things.

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anon6789reply
lemmy.world

I couldn't find any vids of them expanding them, but it seems chicken dissection is common for veterinary students, so there's a number of videos showing them.

They don't look so much like organs like the lungs, just mostly transparent membranes between other stuff.

Very intriguing!

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Maevereply
kbin.earth

These photos are less gnarly than others...

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anon6789reply
lemmy.world

Pellets are less creepy than I expected. I was also surprised that hawks and eagles also make pellets. I had only ever heard about owls making them.

I've cleaned up many of them at work. Once they dry out a bit they just feel like a ball of dryer lint to me. It's amazing how much they are able to extract from everything. This is why you can't go just feed an owl chunks of chicken breast or whatever-they really do extract every last bit of nutrition from the entire prey animal!

(Just to clarify, the photo is an eel going in, not a pellet going out.)

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Maevereply
kbin.earth

Lol. You've become accustomed to my vision! I realized that, thank you for thinking of me. It was the diagram I said was less gnarly.

I'm not hating on our owls! And that's pretty cool to know, a lot of old-timer humans will bite the end off chicken bones to suck out marrow. Lots of minerals there!

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anon6789reply
lemmy.world

It would be much smaller as a pellet, as everything gets squished to the size of their gizzard.

Bird digestion is pretty neat, and after dealing with human, cat, dog, misc mammal, and bird waste, the bird stuff is probably the least worst of the bunch.

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Maevereply
kbin.earth

Now I want to search images...but after breakfast digests!

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lemmingreply
sh.itjust.works

I think human babies do the same thing. That's why they can breathe while breastfeeding.

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anon6789reply
lemmy.world

That was some interesting reading as a guy with no kids. Much more complicated than I was expecting.

Suck-Swallow-Breathe seems to be the term to read up on it.

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anon6789reply
lemmy.world

I study owl this much and you think I haven't picked up some stealth skill points??? 😜

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anon6789reply
lemmy.world

I was originally going to do a title with that, but I didn't know how many would still get KISS references. 😅

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