Regulidae

Kinglets, family Regulidae, are diminutive passerine birds whose name comes from the Latin regulus, a diminutive of rex, or king, referring to the colored crown patches of adult birds. The family holds six species in two genera: Regulus, comprising the goldcrest, common firecrest, Madeira firecrest, flamecrest and golden-crowned kinglet, and Corthylio, the ruby-crowned kinglet. They live in the Nearctic and Palearctic realms, across temperate North America, Europe and Asia, northernmost Africa, Macaronesia and the Himalayas, and rank among the smallest passerines, 8 to 11 centimeters long and weighing 6 to 8 grams, with grey-green plumage and, in males, an erectile crown patch.