Molecular biologist from Texas, here to share my meanderings on nature, science, history, politics, and zombies. Long threads a specialty.
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Cats, bats & weasels have a special little flap doo-hicky at the outer base of their ears that is called the "cutaneous marginal pouch" although most know it as a 'Henry's pocket.'
Let's talk about what it is, what it does & why it may be related to the exceptional hearing of these animals.
This is Daisy. She helped her human make the bed today. Through moral support. 13/10 (IG: daisyneverhelps)
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So it's no surprise they have special ear structures.
Here we encounter a mystery. We're not EXACTLY sure what purpose the Henry's pouch serves, but given the species that have one (e.g. bats), it probably relates to directional ultrasonic detection.
Two theories of mine:
1. It could act as a 'band filter' for specific wavelengths, to prevent interference from competing sound sources, by deadening/buffering mid-range sounds.
2. It acts as a side-baffle, muffling off-axis sound sources to allow ears to more accurately determine direction.
Cats can hear a much wider range of sounds than humans, but they are exceptionally tuned to the ultra-sonic range up to 85 kHz, sounds associated with small rodents.
Their rotating ears amplify these sounds 2-3X, allowing directional detection at great distances, 4-5X that of humans.
Henry's pouch can harbor mites & may need to be carefully inspected & cleaned, preferably not by a cat sibling with a tendency for biting/gnawing.
Cats are exceptional products of evolution, so it's only natural their ears would be finely tuned for hunting things that go *squeak* in the night.
It could also do BOTH or neither.
The second mystery: who is this Henry & why is he studying my cat's ears?
The best guess I've seen is early American physicist Joseph Henry (1797-1878) who did pioneering work in electromagnetism & sound waves.
But history doesn't record his cat studies. 😾
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Alt: two cats (one cream white, one dusty grey tabby) are sitting next to each other on a table, one almost on top of the other. The one on top is gnawing/cleaning the ear of the larger one.
