What is the function of a beaver's dam?

Answer 1

Answer

Beavers build Dams for food storage and protection. They build a dam to make an artificial lake, and then they proceed to build their lodge nearby.

The deeper water in a dam allows the beaver to travel near its home protected from other animals and predators. After the dam is built, the beaver will also dig channels leading away from the new dam, to create safe transport channels for when it is gathering more wood to continue building its dam and lodge.

Once its lodge and dam are built, the beaver will proceed to gather smaller pieces of wood, and take it to the deep bit of the new lake directly next to the dam, and will poke the wood into the mud. The cold water down there helps the wood stay much fresher for longer.

I have observed that beavers in the Rocky Mountains love to eat the bark off of the Aspen trees. To get the bark, they must fell the trees. As they use the trees closest to their beaver made lake, they get further and further away from the protection of the water of their dams. They then use the logs or limbs (they have already eaten the bark) to make the dam higher and push the water back to the edge of the aspen grove little by little. This is so they can reach the water quickly when a predictor comes around.

There is also a study of dam building beavers being serinaded by the sound of running water (via recording) in each case the beavers cover the speakers by the next day to silence the noise. I don't think it because of the sound as much as it is to prevent their predictors from using the sound to sneak up on them unnoticed.