As spring tentatively unfolds around the state, (and the more diligent of us celebrate International Migratory Bird Day - 5/11) the familiar nuisance of black flies also reappears. And as annoying as we find them, as we’ve discussed earlier, they are a sign of healthy eco-system. The presence of black flies means there are sources of clean fresh running water nearby. Black flies are also among the explosion of insect protein in the northeast this time of year, which signals the arrival of more colorful residents…neotropical migrant songbirds. One particular phenomenon that happens this time of year is called, in birding circles, “Warbler Fallout.” These active birds are tiny, between 4-6 inches long. And in many species the male birds are brilliantly colored. Migrant birds been trickling in for over a month now, returning from their winter grounds in the neotropics. Most of the warblers we see in New Hampshire spend those cold months in Central America and the Caribbean, and are now