NREM/ZOOL 4464 – Ornithology Dr. Tim O’Connell Lecture 16 23 February 2011 Last time: •Life of Birds – origin of birds, and of flight. •Avian structure and feathers This time: •feather functions and molt Readings this week: Gill Ch. 4, 5 Feathers grow from follicles arranged in a specific pattern on the skin. These are the “tracts” or pterylae. Featherless areas on the skin are apteria. Feathers in particular tract colored differently from adjacent tracts can create bold patterns in plumage. Feather functions: •insulation (e.g., nestlings) •crypsis (e.g., owls, nestlings) •flight •species/gender recognition (e.g., sexually dimorphic species like Red-winged Blackbird) •special display (e.g., modified feathers of Club-winged Manakin, Marvelous Spatuletail) •waterproofing (e.g., Common Loon) •display (e.g., general display of health and vigor: pink color of Greater Flamingo) •Gathering food (e.g., rectal bristles) •Gathering water (e.g., modified belly feathers of sandgrouse) •Perch prop (e.g., woodpeckers) Bird topography

Some birds have more than 9 primaries:

The tail feathers (rectices) are also considered to be flight feathers. There are usually 12, and they are numbered from the inside, much like the remiges: