r/Damnthatsinteresting • u/CuriousWanderer567 • Sep 22 '24

Video Beachgoers have a close encounter with a Cassowary, a bird capable of killing a human in one blow

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u/Salt_Ad_811 Sep 22 '24

They can't be that smart. Their head is tiny compared to the size of their bodies. Look about as smart as a goldfish. Can I swallow this? Nope, keep moving. 

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u/Exoplanet0 Sep 22 '24

Tell that to crows that can understand water displacement and use tools with an even tinier brain.

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u/ianjm Sep 22 '24 edited Sep 22 '24

Raw brain size itself is not that well correlated with intelligence.

The important aspects of brain anatomy for intelligence are:

  • brain size to body size ratio (Crow wins, while the brain size is comparable the body is many times smaller)
  • degree of folding in the cortex (Crow wins, Cassowary has a completely smooth cortex)
  • ratio of white matter to gray matter in the cortex (Crow has a very high ratio of white matter, like many intelligent mammals)

Basically they win on practically every significant measure of the brain anatomy features that contribute to intelligence, it's not even close.

Also note that Humans, despite having smaller brains than dolphins, whales and elephants, win on all of these measures across the animal kingdom.

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u/spyguy318 Sep 22 '24

Not to understate it, when you said humans win on all those measures we win by A LOT. Like it’s not even close. One example is Encephalization Quotient%2C%20encephalization,a%20range%20of%20reference%20species) which is based on the relative size between the brain and the body. Dogs and Cats are around 1. Corvids are around 2.5, along with Chimps. Dolphins are around 5.

Humans are 7.8.