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20 Cards in this Set
- Front
- Back
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Major feather uses |
-thermoregulation -aerodynamics -coloration |
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Modified uses |
-swimming / water repellency • -sound production • -hearing • -protection • -tactile sensation • -support |
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Beta-keratin |
strong fibrous protein polymer in birds and reptiles in nature skin, scutes, claws, beaks |
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Anatomy of a typical body contour feather |
Shaft = Calamus + rachis Vane = rachis + barbs Barb = ramus (central axis) + barbules Barbules = end-to-end single cells (sometimes with barbicels) Fused barbs can look like strips of plastic (e.g. Cedar Waxwing) |
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Feather base vs. outer part |
Feather base – fluffy, long barbs and barbules without barbicels Outer part of vane firmly textured, interlocking structure. Well-developed hook barbicels barbicel hooks can slide along the barb they're hooking, adding flexibility |
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Pennaceous vs. Plumulaceous |
Pennaceous: With barbicels Plumulaceous: Downy, without barbicels |
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Proximal vs. distal barbules |
Diagram |
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Contour feathers
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Outermost feather Strong, stiff For support in flight, waterproofing Controlled at follicle by muscle Remiges: Largest ones, for flight |
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Bristles |
Modified feathers Nightjars Around mouth or eyes Tactile sensation |
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Semiplumes |
are found between other feathers Additional warmth Intermediate feather With a rachis but without barbicels (hooklets) |
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Down Feather |
Without barbicels or rachis insulation Juvenilles mostly down feathers |
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Filoplume |
With rachis and without barbs (unless very few) lack specific feather muscles but have sensory receptors next to the base of the feathers |
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Powder Downs |
Disentegrated sheaths, barbs Keratin Powder Water proofing agent Keeps feathers clean Does not molt Grow in dense yellow patches (on breast, belly, or flanks of herons and bitterns but in other birds (pigeons) its more scattered throughout plumage) |
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Flight Feathers: Remiges |
Aerodynamic Function Primaries (on d2 and handbones) 9 or 10 Secondaries (on ulna) , 6-40 Forward thrust on Downstroke Assymetric Vane Friction barbules (keep feathers together) |
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Flight Feathers: Retrices |
Tail flight feathers (on pygostyle) 12 Steering, braking Display Propping (woodpecker) |
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What destroys Feathers |
Abrasion Fading Ectoparasites Bacteria |
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Feather Growth: Follicles |
Same follicle, different feather types over time
New growth, pushes out old feather Follicle grips feather = muscular tightening and friction Frightened=loosen grip and molt |
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Follicular Collar |
Follicular Collar = persistent ring of feather stem cells |
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Feather Growth |
Keratinocytes (epidermis) proliferate and differentiate Feather growth includes a concentration of dermis cells and the epidermal placode around it Epidermal cells differentiate into the protective sheath Dermal papilla in the middle of the follicle |
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Pterylae |
One of the area of the skin that birds can grow feathers 8 major areas Feather x2-3 the weight of their bones |
