Two- -thirds of bird species in North America, already disappearing at an alarming rate, face extinction unless immediate action is taken to slow the rate of climate change, the National Audubon Society said on last week. If the emission of greenhouse gases blamed for global warming isn't slowed, 389 out of 604 species in North America will face extinction. 'We are in the midst of a bird emergency,' Audubon's Chief Executive David Yarnold said at a news briefing.