They are clearly biased on this subject (and many others), as you seem to be yourself. The NPR article you linked literally has the very first words as "Conservative Lawmakers" purely to stir up the base that they know uses their site. And before you try to get on me, I'm apolitical since I think both sides are full of morons.
The 90% is extrapolated from the current wolf population compared to the minimum number considered acceptable, it's click baity for sure but technically not incorrect. What I'm taking issue with is the phasing that you and the article uses as if the hunting of these wolves is being mandated or is a goal the state wants the reach. The minimum number is just that, the minimum, and considering the restricting on hunting wolves were mostly eased for cases where there is a clear indication the wolf is harassing or trying to kill livestock and not the ones out minding their own business far away from people, the likelihood that 90% of the population will be culled is ridiculous. You also seemed to have missed the fact that any wolf killed in this way is the property of the state, no trophy hunters would waste their time stalking a wolf (which are relatively rare compared to the vast open spaces they inhabit as predators), waiting for it to attack another animal someone owns before killing it only to turn it over to the state. Sure a hunter might kill one illegally, but if that was the case they would have done so regardless of this legislation and clearly not many bothered with that either if the wolf population is so high currently. That's another thing you and the articles seem to be missing is the idea of perspective, killing up to 90% of an animal's population sounds bad on paper, but considering the Idaho Wolf Conservation and Management Plan (yes the limit was put in place by Idaho itself, I have no idea where you got the idea that it was a federal limit stopping them from exterminating all of the wolves, as if any sane government would do that in the first place) did their home work years ago and crunched the numbers and successfully brought the wolf population back up so high, too high apparently, how do YOU know the population doesn't need culling? People itt are talking about ecological concerns from too few wolves, but you know there can be too many of them as well right? I won't claim to be an expert on the topic, but I highly doubt any of you getting upset over sensational headlines are either, maybe the people who wrote the laws aren't 100% right either, but considering they know much more about the situation in the area and can make amendments as needed to the law I see no reason to assume the absolute worst case scenario will happen (that worst case scenario STILL being within the bounds of what the wolf population could recover from).
So yeah, that's my issue.
I admit you made some good points but how can 1,500 wolves be "too many?" There are like half a million deer and 150,000 elk in that state. And, as pointed out, only around 100-150 cattle killed from wolves. So, what is the justification for "too many?" The Idaho Fish and Game department itself opposed the bill and it was not consulted (which I learned from reading the Nat Geo article, and could not have learned from reading the bill itself making it in a way a superior font of information to the direct source itself) but the bill was rushed through at the end of session.
Also you wanna talk about bias, how about several of the congressmen/congresswomen being ranchers? Being spooked by wolves who've killed such a small percentage of their cattle population that my calculator can't even render it without resorting to scientific notation. It's not only inhumane but highly irrational/illogical to overreact to such a tiny percentage.
I think I have the ranchers figured out, but I don't know why the hunters have such a hate boner for wolves. I would say it's the competition to game, but again there's so much elk and deer already I don't see what the problem is. Are they scared of the wolves? I can only assume it's the same type of small pecker bloodlust we see from people who trophy hunt lions from helicopters and such.