Once in a while we get to travel so far off-the-beaten track, there's hardly a track at all. That was the case last year when we went to the mountains of western Colombia. There are some 2,000 species of birds in that South American country, more than anywhere else on Earth – partly because of its diverse geography but also, surprisingly, because of war. Decades of fighting among the Colombian government, left-wing guerrillas, right-wing paramilitaries, and narco-traffickers made some areas so dangerous, few people could go there, preserving the birds' habitat. But since 2016 when Colombia's government signed a peace deal with the FARC, the largest left–wing guerrilla group, it's gotten safer to travel, and all those species of birds in untouched forests have become an important part of a growing ecotourism industry.…