Hi, @robmenzies.

You are of course right; they cannot possibly have over 400 offspring every month. It is like you said, where the offspring breeds with itself, the next generation breeds with itself etc. This gives us an exponential growth that ends up with 16,000 animals after three years. I'm not sure if the number is realistic or not, but it is provided by the US fish and wildlife agency, so it is an official government statement, so take it as you will :) 

Thanks for pointing this out by the way! I edited the text to make it more clear that the 16,00 babies are not all born from a single mother. 

It's cool to hear that it's a delicacy! I'm sure it's pretty sustainable. I've heard some ecologists argue that we should be shooting beavers for food here in Norway, but the culture here never really adapted to that, so it's a really niche type of meat. I guess they both reproduce easily and are easy to shoot, so why not? :)