Bird populations in the US and Canada have dropped by 29 percent in 50 years

According to a new study from the Cornell Lab of Ornithology and the American Bird Conservatory, bird populations in both the United States and Canada have declined 29% (about 3 billion birds) since 1970, thus signaling an ecological crisis. "Multiple, independent lines of evidence show a massive reduction in the abundance of birds," said lead author Ken Rosenberg, a senior scientist at the Cornell Lab of Ornithology and American Bird Conservancy. "We expected to see continuing declines of threatened species. But for the first time, the …