Sentinel Journal: Seabirds heading farther north to breed, robins showing up two weeks early, songbirds unexpectedly chirping away in northern Ontario. Many researchers are tying these and other behavior changes in birds to global climate change. According to the American Bird Conservancy, birds that rely on specific types of habitat could become extinct if global climate changes continue. The ABC report “Global Warming Threatens Many Bird Species” says that ranges of many bird species …