Which implies the Beaver has more rights than the Fetus.Not in this universe.
You may not burn your neighbour's house down, either. Does the house have rights?
The state has an interest in beavers. Beavers do not have rights. The state has an interest in maintaining biodiversity and ecological balance. It can legislate to prohibit you from doing something that would decrease biodiversity and upset the ecological balance. It can outlaw killing beavers. This does not recognize that beavers have rights, or give beavers rights. If it did, the beaver (assuming you were unsuccessful) could sue you. I don't think beavers have figured that out.
Trust me -- if you are lost in the forest and haven't eaten for 10 days and a beaver crosses your path and you choke it to death and eat it, you cannot be convicted. The defence of necessity will protect you: you have a right to life and you can act to preserve your life if it is endangered.
The beaver doesn't. If it tries to eat you, no matter how hungry it is, you can go ahead and choke it.
You would be entitled to whack the beavers chewing your trees if it weren't for the law prohibiting it. And the state would not have to make that law; it gets to decide whether it's necessary and wise to do so. If it were a five-year-old chewing your tree, or your mother-in-law, or the old guy down the street, the state would have to make a law prohibiting you from whacking them, because the state has a duty to protect them.
The state obviously doesn't have a duty to protect post-viability fetuses, because not all US states have:
http://members.aol.com/abtrbng/stablw.htmForty states and the District of Columbia have laws banning most post-viability abortions
(could be out of date, but the point remains: years after Roe v. Wade, numerous US states had not enacted legislation to advance their "compelling" interest in "the potentiality of human life")