Passeriform - Plumage, Pterylosis, Molt

Passeriform - Plumage, Pterylosis, Molt: Plumage and the number and distribution of feathers of passerines are considered important taxonomic characters, especially in determining the genera, species, and subspecies. The passeriform vocal apparatus exists in four basic types: unspecialized, tracheophone, intermediate tracheobronchial, and oscine.
Passeriform, any member of the largest order of birds and the dominant avian group on Earth today. Passeriforms (or passerines) are true perching birds, with four toes, three directed forward and one backward. These birds occur in abundance on all continents except Antarctica and on most oceanic islands.

Passeriform - Plumage, Pterylosis, Molt

Glossary of Bird Terms

Passeriform - Vocalization, Song, Calls

Bird Academy's A-to-Z Glossary of Bird Terms

Passeriform - Plumage, Pterylosis, Molt

Bird Plumage Variations and Abnormalities

Plumages, Molts, and Structure - Say's Phoebe - Sayornis saya - Birds of the World

Extent of post-juvenile moult on the wing in 1y/2y Graceful Prinia

Passeriform - Plumage, Pterylosis, Molt

Introduction to the Morphology, Development, and Ecology of Feathers