Calamus

rachis

vane

barbs

barbules

hooklets

Flight feather

semiplume

downy feather

bristle feather

filoplume

Tail feather

feather development steps

feather evolution

Biochrome Pigments

Melanin

Carotenoids

Porphyrins

Structural Color

Lake Natron, Tanzania

Feather tracks

Feather care

Cryptic color pattern

disruptive color pattern

Countershading color pattern

Bold color pattern

Molting

molting pattern

psilopaedic

ptilopaedic

Plumage types

Overcoming Gravity + Drag

producing lift + thrust

alula

wing tip vortices

Muscle fiber metabolism

Unidirectional ventilation pattern

Flight Muscles

Parabronchi

Songbird/raptor vision

sclerotic ring

retinal oil droplets

fovea

Pecten

magnetic field detection

bird external ear

bird middle ear

bird inner ear

bird hearing

Bird taste

nasal conchae

Bird brain size

(hyper)pallium

brain lateralization

hippocampus

sound producing muscles

Motor control of vocal

Areas of pallium

Song Learning Pathway

Song Learning pattern

Repertoire