a feather from the whippoorwillfacultyweb.cortland.edu/broyles/411/feathers.pdfflight feathers •...

A Feather from the Whippoorwill (Emily Dickinson, 1955)

A feather from the Whippoorwill

That everlasting -- sings!

Whose galleries -- are Sunrise –

Whose Opera -- the Springs –

Whose Emerald Nest the Ages spin

Of mellow -- murmuring thread –

Whose Beryl Egg, what Schoolboys hunt

In "Recess" -- Overhead!

Photograph by Robert Clark—Audubon Magazine 2012

Avian Feathers

Function, Structure & Coloration

• Tremendous Investment

– 25,000 on Tundra Swan

– 2-4,000 on songbirds

– 970 on hummingbird

• Feather Mass=2-3X Skeletal Mass

• 91% Protein (keratin)

1% Fat, 8% water

• Waxy secretions and fatty acids from uropygial gland protect feathers

Feather Outline

• Functions in addition

to flight

• Structure & Variation

• Coloration

– Pigments

– Structural Colors

• Origin of feather color

and recent fossil

discoveries

Do feathers have a function or are

they just an expensive costume?

• Insulation

• Sound production

• Sound capture

• Camouflage

• Aerodynamics

• Sexual selection

• Protection

• Nesting, diet, other

Diverse Functions

• Crypticity

– Disruptive color patterns in

Killdeer and meadowlarks

– Mimicry in bitterns, snipe, and

woodcock

Diverse Functions

• Sound production for attraction – Booming of Ruffed Grouse wings

– Primary flight feathers of American

Woodcock

– Hummingbirds

• You Tube Hummingbird Music

– Manakins

• Manakin Wing Sound

Diverse Functions

• Sound gathering properties

of owls and some hawks

– Eastern Screech Owl

– Northern Harrier (hawk)

http://www.wisenaturephotos.com/NEW!!!%202-10-06.htm

Diverse Functions

• Support

– Tail rectrices of woodpeckers

• Protection

– Bristles over nares

Diverse Functions

• Display

– Aggression

• Red-winged blackbird threats

• Sun Bittern

– Attraction --sexual selection

• Peacock tails, colorful plumages

• Tail length in Barn Swallows

Diverse Functions

• Thermoregulation

– Heat retention, natal down

– Convective heat loss--radiation cooling

– Solar heating

White in Winter

• Air spaces in feathers scatter light

• Dual Functions – Insulation

• white plumage and pellage has a higher insulation value

– Crypticity

• avoid predation or be a more effective predator

Feather Structure

• Epidermal and epithelial

development

• Terms

– Rachis

– Barbs, barbules

• Proximal and distal

– Superior & inferior

umbilicus

– Pennaceous & plumaceous

barbs

– Pulp caps

BOARD

ILLUSTRATION

Down Feathers & Contour Feathers

• Plumaceous vanes close to

skin provide excellent

insulation

• Heavy down coat in

waterfowl • Cover feathers

• Smooth the non-

aerodynamic edges and

folds of the avian body

• Substantial pennaceous

and plumaceous barbs

Bristles & Filoplumes

• Thin, hair-like, facial feathers

– Protection of eyes--woodpeckers

– Tactile, insect collection--nightjars

Filoplumes

• Whisker-like feathers

hidden throughout

plumage

– Believe to enhance tactile

and sensory capabilities

http://www.reinhold-necker.de/seite4.html

Flight Feathers

• Remiges

– Primaries attached to manus

– Secondaries attached to ulna

– Provide airfoil surface for flight

• Rectrices

– Tail feathers provide lift, rudder

and breaking capabilities for

birds

BOARD

ILLUSTRATION

Cedar Waxwing

1º 2º

Rectrices

Flight Feathers

• Remiges

– Primaries attached to manus

– Secondaries attached to ulna

– Provide airfoil surface for flight

Flight Feathers

• Rectrices

– Tail feathers provide lift, rudder

and breaking capabilities for birds

Feather Coloration

• Melanins--oxidized products of

tyrosine

– Dark colors--black, gray, dark brown, brick

red

• Temperature regulation

• Longevity of feathers

• Gloger’s Rule--darker colors in

humid tropical regions

• Melanosome shape and density

determine whether feather is gray,

black, or rusty

What do the following birds

have in common?

Snow Bunting Whooping Crane

What do the following birds

have in common?

Snow Goose Northern Gannet

What do the following birds

have in common?

Gull Red-footed Booby

What do the following birds

have in common?

Scarlet Tanager American Goldfinch

Feather Coloration

• Carotenoids--diet derived pigments of a plant source

– Brilliant yellows, oranges, and reds

– Rarely found in wings

• Carotenoid Stories

– Cedar Waxwings

– Flamingos

– House Finch

Recent color variation in rectrices of Cedar Waxwing.

Orange or Yellow?

Where does the Egyptian Vulture

obtain its Carotenoids?

Moniguero--dung eater in Spanish--Coprophagy

Psittacorfulvins “the other red pigment”

• Found in all members of the Psittaciformes

• Endogenous production

• Resistant to Bacillus licheniformis

Structural Colors • White, blue, and some green colors are

formed by air spaces around deep

embedded melanosomes

– Short wavelength light is easily reflected in air

• Blue Jay, Indigo Bunting, Honeycreepers

Structural Colors

Iridescence

• Structural color where the viewpoint of the observer determines and direction of light source vary

• Interaction of surface layers, melanin granules, and air spaces of barbules

• Hummingbirds & grackles

Origin of Feathers & Coloration

• Anchiornis huxleyi

– meaning “near bird”

– 150-161 MYA

– Considered a dinosaur with

wings and feathers

– Glider

• SEM analysis of feather

impressions

Li et al., 2010. Plumage color patterns of an extinct dinosaur. Science 327:1369.

Anchiornis Feather Coloration

Melanosome Fossil Impressions

Wings

Head

Anchiornis Feather Coloration

Feathers of Dinosaurs & Birds

P owered Flight

First Appearance of Color Patterns

In Gliding Dinosaurs

Ancient & Modern Fossil Birds

First Appearance of Color Patterns

in non-Volant Dinosaurs

Sinosauropteryx

Protective Care for Feather Investment

• Preening

– Removes ectoparasites

– Streamlines feathers

• Oil secretions

– Uropygial gland

– Keep feathers supple

– Anti-parasite chemical

• Dust & Water Baths

• Anting--formic acid protection

• Sunbathing

– Heating in TVs

– Drying in Anhinghas

Feather Detectives

• Why would professionals from the

following disciplines / organizations want

feathers identified?

– Federal Aviation Administration

– FBI and USFWS

– Archeologists

– Ecologists

Plumage / Molts

• Basic--non-breeding plumage, female-like

• Alternate--breeding plumage

• Timing--post-breeding, pre-migratory – Usually annually, sometimes 2X

• Feathers are molted in sequence – Inner primaries to outer primaries

• Why molt?

www.jkcassady.com/images/1SCTA0902.jpg

Molting and Life History of

American Redstart

• Hydrogen Isotope data

– Indicates location of

bird during molt

• Males that molt on the

run have lower

carotenoid content in

feathers

Norris, et al. 2004. Reproductive effort, molting latitude, and reproductive effort in a

migratory songbird. Science 306:2249

Molting and Life History of

American Redstart

• Males that fledge young,

molt further south

• Males that fledge young

later in the season molt

further south

• Males with greater

reproductive effort molt

further south

Balancing Reproductive Effort and

Survival in American Redstarts

• Males that delay migration,

molt during stress, arrive later

to winter grounds, and may

lower reproduction the

following year

• Males with low reproductive

effort, molt during period of

low stress, arrive earlier to

wintering grounds, and may

improve reproduction the

following year.