> The reason they build dams is to create deep water that gives them protection from predators.
How do they know the reasons beavers build dams? Did these reporters fact-check this by asking the beavers?
How do they know the reasons beavers build dams? Did these reporters fact-check this by asking the beavers?
Obviously it's a shorthand, but the interesting thing here is that different biologists come up with different implicit reasons. To an evolutionary biologist, the reason for a behaviour is how it grants an evolutionary advantage, so to them the reason for building dams is to create deep water which provides protection from predation.
But behavioural biologists look at what triggers particular behaviours, and we actually know this one thanks to experiments: Beavers hate the sound of running water. If you set up a speaker and have it play running water sounds, beavers will pile sticks on top of it! There's no grand dam-building plan; just mindlessly placing sticks wherever the noise is coming from.
And they were more likely to die because there wasn't a body of water and pile of sticks nearby to hide and live in.
That isn't actually evidence that they don't like the sound. They might like placing sticks where they hear it.
As far as I'm aware, cats don't care at all what colour fur other cats have.
Encountering someone from far enough away that they would be part of a distinct genetic or cultural group was basically unheard of. That's not to say it didn't happen at all, there would be migrations and smaller groups would potentially travel long distances out of necessity, but it simply was not a part of normal life. The idea that a fear of different looking people provided any meaningful benefit in the past simply does not pass the sniff test.
Further, wars were almost always between regional neighbors then as well.
Some types of anti-beaver-damn measures work by eliminating the sounds and vibrations.
Correlation does not mean causation.
Naked beaver logic.