Here's yet another scientific idea that sounds crazy until you consider it seriously: after years of watching their family members get killed by poachers, elephants across Asia and Africa are suffering from PTSD.

From within and around whatever patches and corridors of their natural habitat remain, elephants have been striking out, destroying villages and crops, attacking and killing human beings. ... Since the early 1990's, for example, young male elephants in Pilanesberg National Park and the Hluhluwe-Umfolozi Game Reserve in South Africa have been raping and killing rhinoceroses. ...

In "˜"˜Elephant Breakdown,'' a 2005 essay in the journal Nature, [scientist Gail] Bradshaw and several colleagues argued that today's elephant populations are suffering from a form of chronic stress, a kind of species-wide trauma. Decades of poaching and culling and habitat loss, they claim, have so disrupted the intricate web of familial and societal relations by which young elephants have traditionally been raised in the wild, and by which established elephant herds are governed, that what we are now witnessing is nothing less than a precipitous collapse of elephant culture.

The article (from the Times Sunday magazine) is long, but it's well worth reading and surprisingly convincing, even for the most skeptical reader. Bradshaw is leading a lot of the scientific work, but the character who stands out most for me is Eve Abe, who draws a stunning parallel between what's happening to the elephants and the trauma suffered by the human orphans who have watched their parents die in Africa for generations. If you make it to the end of the article, you will never look at zoos and circuses the same way again.