Blue Gray Gnatcatcher by NG | Feb 25, 2018 | GnatcatchersSpecies of bird The blue-gray gnatcatcher (Polioptila caerulea) is a very small gnatcatcher native to North America. Description It is 10–13 cm (3.9–5.1 in) in length, 6.3 in (16 cm) in wingspan,[2] and weighing only 5–7 g...