These beavers have become one of my most used "Dino". Their ability to hold wood at 25% weight and stone at 50% weight comes in handy when building. I recommend lvling weight and breeding high lvl beavers. Breeding is very easy. Once they are born and imprinted let them wander around bushes in a protected area. They will passively collect berries to their full weight capacity (full as in once they're grown). This means they are self sufficient even in the baby stage.
Actually quite good fighters, my rank 20 is able to take out carnos and if you are near water, it can kill a Rex. Also very good transporters because of the weight reduction. I'm planning on getting 4 of them so I can have a squadron.
Easiest and safest way to raid a beaver dam. Put a small cabin on a raft only need 3 walls a door way and a door and roof. Just drive over dam with raft and let the dam glitch up threw the bottom of the raft and then take off once u have emptied it
You could capture wild castoroides and put them in damming pens, and if you do, put them in half water half land pens. They will dam better like that. If you put more beavers in the same pen, they will, again, dam faster. This makes a good cementing paste farm, but will also give wood, silica pearls, rare flowers, and rare mushrooms. This is quite a bit of work though. If you're not into it or don't have enough resources or a good bird, you could just find an area( most likely in or near water) that beavers are around and passively build dams. When you check them, destroy them. Resources don't respawn in the same dam they already were in to the best of my knowledge. P.S. If you tame a beaver, there is no way to let build a dam ( I've tried ?)
This and the Beelzebufo are the most useful and versatile dinos someone can tame, especially when you're not playing on a public server where you have to worry about other taming things to fend off other players. Besides the awesome wood gathering, the Casteroides also has decent stats across the board, is a great underwater mount, and it's saddle functions as a smithy!