[Ed. note: A bilateral ceasefire was signed by the Colombian government and FARC on Wednesday, June 22, 2016, ending 50 years of bloodshed.] Three a.m. is horrible. Almost nothing happens at that hour that you won’t regret later. And yet, at three on a Wednesday morning in June, here I am folding myself into the back of an ancient Toyota Land Cruiser. What, you ask, could possibly inspire me to embark on a bleary pre-dawn odyssey up the flanks of the eastern Andes? To do so voluntarily, even eagerly? The opportunity to see something I could see nowhere else in the world, that’s what—the newest bird known to science, first described in March 2015: the Perijá Tapaculo. The Perijá Tapaculo’s namesake is the Serranía del Perijá—the northernmost extent of the eastern Andes. Colombia and Venezuela share a long stretch of border across these mountains, and these peaks and valleys have been a stronghold of guerrilla activity for decades. Even while other parts of...