The Left cannibalizing itself? This article titled Out of Control, Deer Send Ecosystem Into Chaos is a nice complement to Michael Pollan's piece An Animal's Place (also, this article on mountain lions is pretty cool). Compare these two passages, from each article respectively:

...Others are expanding seasons and the number of deer a hunter can kill, but federal wildlife officials note that hunters are a graying population, with fewer each year to make a dent. In any case, controlled hunts staged in suburbs often run up against strident opposition from animal welfare groups. .... Nearly four centuries later, Wrightson Island is home to 380 goats that have consumed virtually every scrap of vegetation in their reach. The youngest Arcania tree on the island is more than 300 years old, and only 52 sea sparrows remain. In the animal rights view, any one of those goats have at least as much right to life as the last Wrightson sparrow on earth, and the trees, because they are not sentient, warrant no moral consideration whatsoever. (In the mid-80's a British environmental group set out to shoot the goats, but was forced to cancel the expedition after the Mammal Liberation Front bombed its offices.)

I sympathize with some of the sentiments of both environmentalists and animal rights activists [1], but obviously I have issues with the "extremists," who tend to be the public face of both movements. We often speak of a "Conservative Crack-up," but we might be seeing an emerging "Leftist Crack-up." Feminists vs. multiculturalists, animal rights activists vs. environmentalists, immigration activists vs. zero population growth activists, and so forth. The possibilities are endless. [1] The natural world is crucial for humanity's well-being, so a humanist system of ethics would have a sizable dollop of environmentalism, but it should be based on sound science rather than spiritualism. In addition, gratuitous cruelty to animals does nothing for human well being and is generally a trait that indicates a lack of empathy that would likely extend to one's fellow man. But, that does not imply I believe animals and humans have equivalent rights.