The Blue-gray Gnatcatcher is a very small woodland bird with a long tail, usually seen flitting about in the treetops, giving a short whining callnote. They are tiny (about 10cm or 4 inches) with long legs; a long tail; and a thin, straight bill. described as energetic and rarely slowing down, fluttering after small insects and making it almost impossible to capture them with my camera. But for once! The Blue-gray Gnatcatcher is the northernmost-occurring species of gnatcatcher, and the only truly migratory one, most members of its genus live in Central and South America.