WILD 3580 1st Edition Lecture 29 Outline of Last Lecture I Power Promoting Adaptations Outline of Current Lecture I Feather Types II Number of Feathers III Plumage and Molts Current Lecture I Feather Types 1 Contour Feathers Form the outline of the body Large vane Flight feathers o Remiges flight feathers of the wing o Rectrices tail feathers Pterylae feather tracts where contour feathers grow Apteria areas between feather tracts 2 Semiplumes Loose vane feather Lacks hooklets hamuli Grow at the margins edges of the feather tracks Functions o Insulation by trapping air o Providing flexibility o Buoyancy for some birds 3 Filoplumes Hair like feathers that lack a vane or have a much smaller one Extend the contour feathers 4 Bristles Occur around the mouth nostrils or eyes Vaneless These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute II III Rictal bristles enlarges bristles around the mouth 5 Down downy Small soft feathers that lack a vane For insulation Overlaying contour levels Not confined to the pterylae 6 Powder Down Powder functions to waterproof feathers Ends of feather disintegrate into a powder Only type that can grow continuously throughout life 7 Aftershaft Accessory feather Grows at the base of another feather Correlation of temperature and occurrence of aftershaft Provides extra insulation Number of Feathers Ruby throated Hummingbird 940 feathers Whisling Swan 25 216 feathers The bigger the bird the more feather it has Feathers gram of body weight o Smaller birds have more feathers per weight o More surface area to volume ratio for insulation Plumage and Molts Plumage entire feather covering of a bird Molt sequence of feather replacement o Certain feathers fall out at certain times of the year o Temporal sequence Natal Down first plumage Altricial hatch with only a few down feathers mostly bare skin not capable of coordinating movement or maintaining temperature Nidicolous nest inhabitant stay in the nest after hatching Precocial hatch with a complete down covering little bare skin can coordinate movements and maintain temperature Ex Ground nesting birds acceptable to predation Nidifugous nest fugitive leave nest soon after hatching Juvenal Plumage starts looking like adults less down o Partial Molt only contour feathers in certain pterylae are replaced not the flight feathers o Complete Molt all feathers including flight feathers are replaced
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