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.

Wing feather topology, numbering, and typical molt sequence among

Passerine - Wikipedia

OFO - Page Site

Passeriform - Songbirds, Adaptations, Foraging

Passeriform - Plumage, Pterylosis, Molt

Passeriform - Plumage, Pterylosis, Molt

Frequency of wing‐feather replacement resulting from preformative molts

Plumages, Molts, and Structure - American Pipit - Anthus rubescens - Birds of the World

Stable isotope analysis of an aberrant Painted Bunting (Passerina ciris) feather suggests post-molt movements

Molt in Birds: A Basic Guide - Avian Report

Passeriform - Plumage, Pterylosis, Molt

Plumages, Molts, and Structure - Field Sparrow - Spizella pusilla - Birds of the World

Plumages, Molts, and Structure - Unicolored Jay - Aphelocoma unicolor - Birds of the World