Defense Posture

Linda Rose Forney   503.460.7908

Used for insulation (warmth, cooling, bouancy, and flight, waterproofing, coloration, communication,
​incubation and brooding of eggs and young, and protection (as in camouflage).

Wings can be c
omplex integumentary appendages! Instead of arms or fins, birds use their
wings for flight, expression, balance,

Begins as a pin feather encased in a protective sheath. Growing feathers have a
purple shaft (this is blood) within their casings and will bleed profusely if broken open. As a
feather matures, blood dries up as the vane breaks out of its sheath. What is left is a hollow "quill."
It is this quill that soaks up ink for writing such as was used in days gone by.

A formed feather is dead like hair. It does not hurt to trim a mature feather.
It does hurt badly to cut into a blood or pin feather because it is living. Birds can
lose a lot of blood from a broken tail or wing pin feather, and sometimes death
occurs. But once the shaft is completely removed, bleeding
stops and a new feather begins to grow in right away.

​C​entral shaft
is hollow, also called the quill, or rachis. Vanes are made of barbs
that are arranged side by side up the shaft of the feather. These barbs have tiny hooks called barbules that birds zip together when pulled apart. Pull feather barbs apart, and then try to zip them back in place. You will find it very difficult to do; yet a bird has it mastered with perfection.  
Primaries are the longest outer feathers on wings that curve forward (attached to “hand”). 
They are the primary flight feathers. Clip these feathers off, and a bird is left flightless. However, small birds can still gain enough air under their wings to fly, though not high or far.

Secondaries begin behind the primaries and curve backward (“forearm”).

Tertiaries are attached to the “humerus” or upper arm bone. Together they are called remiges.

Coverts are the upper shorter feathers that cover the remiges.

are called retrices which are also partially covered with coverts.

Bodyfeathers When cold, birds will tuck in their head and sit on their feet to keep sensitive body parts warm! Ever notice how some birds can sleep out in the snow, rain, and wind? Aha, that is the beautiful function of a "coat of many feathers!"

Molting~loss of existing feathers~
generally occurs evenly on both sides a few feathers at a time. 
This allows for continued insulation and even flying. Not all birds molt this way. 
Some ducks go through a severe eclipse where they moult their primaries and are unable
to fly for a period of time. The feather coloring of a male is replaced with drab shades (like a female duck), to help camouflage him while he cannot fly. 

​Fright molt occurs when a bird is frightened. As a defense mechanism feather are instantaneously dropped if grabbed from a predator. Compare this to a gecko losing its tail if grabbed. Doves and pigeons
will lose many feathers easily if frightened when caught.

 Feathercolors come from a combination of two pigments: melanins (blacks and darks),
​and carotenoids obtained by diet (yellows and reds).

Feathers are either iridescent or non-iridescent. Iridescent colors are created by prism-like
structures in the feathers rather than color pigments.  These prisms reflect light to allow it to
reflect and split into rich colors.  Have you ever noticed how feathers and  hair are dark
when wet?  That is because these prisms are unable to reflect light when they get wet.  

The powdery substance on many birds is found on the barbules of powder-downfeathers.
These feathers never molt, but disintegrate at the tips to produce a protective powder that acts
as a feather conditioner and waterproofing aid.  Some people are very allergic to this powder. 
Cockatoos are notoriously famous for this type of powder~down. Many a 'Too owner has had to part
with their beloved bird after realizing they are allergic to this powder.

Molting generally has everything to do with hormonal changes, and is not based on
the weather as with most mammals. After breeding season many wild male ducks will go
through an eclipse right after breeding season. However, many wild females retain their
same coloring which is a good camouflage during molt.  

Semiplumes fall between contour feathers and down feathers. These feathers lie beneath 

the contour feathers and  should not be confused with down. Semiplumes are distinguished

from down feathers in that the rachis is longer than the longest barbs.  Semiplumes offer

insulation, feather contouring, and thought to provide flexibility in areas such as the base

of the wings. Another way to identify a semiplume is to notice that it looks just like

a feather, but the barbs are unzipped and very fluffy.

Downy feathers as well as Simiplume feathers are able to trap pockets of air close to the bird's

body to help keep it warm. How much body heat they keep can be adjusted by arranging their

feathers to trap more or less air. If you see birds fluffing their feathers in the cold that is

their way of adding extra air to trap body heat and keep warmer. Controlling body

temperature to keep their body temperature steady birds can either expose their

heads and feet to cool, or tuck them into their feathers to keep warm.

The stronger and ridged contour feathers shield birds from wind. The tough material they are

made from, beta-keratin is water and wear resistant. Darker colored feather might also

provide protection from the sun. The interlocking feather barbs and a special coating that is

either oily or waxy create a shield that water runs off. Swimming and diving birds use their

half-spread out wings in a flying motion to swim in water. Penguins have developed their

wings into stiff flat flippers that make them great swimmers.

Floating  is accomplished by using the trapped air in downy feathers during flight.

Snow-shoeing is one of the more unusual feather uses. Grouse, chicken-like birds  that live

in snow covered areas have feather covered feet in the winter that increase the size of the foot

just like snow-shoes. This keeps the birds from sinking into the snow.

Tobogganing! Why walk if you can slide, or in the case of penguins toboggan. The Antarctic

birds flop down on their smooth belly feathers and use their flipper-like wings together with

their feet to move themselves, toboggan-like, across snow and ice.

Bracing is used as a third "foot" so to speak, as support when on the ground or climbing the

sides of trees such as seen with woodpeckers and wrens. 

Feeling feathers which do not have nerves can still be felt where the feather attaches to the bird's body.

We can compare this to our own hair when it is cut or plucked! Birds can adjust the position of their feathers and posture depending on the stimulation of the nerves.

​​Hearing, especially owls, have their face feathers arranged like two dishes (facial discs) to

collect and channel sounds into their ears so they can more accurately locate prey in the

dark (parabolic reflector).

Making sounds?  We think of bird sounds either as songs or calls, but using their

feathers birds are able to make many different sounds like humming, drumming, and whistling.

Muffling the the sound of their wings, owls and other predator birds are able to approach

a prey in total sound of flapping for these great hunters!

While foraging for food,  birds like herons that hunt for fish in water of lakes and

streams will use their feathers to form an umbrella over their head. This might make

it easier to see fish in the water. 

Insect eating birds have long feathers called rictal bristles which are found around

the mouths of many insect-eating birds. These may either act like a funnel to catch

the insect in the air, or they may protect the eyes while catching an insect. Other birds

use feathers on the side of the mouth to select fruits. Hummingbirds help to pollinate

flowers when foraging for sweet nectar when the feathers around their head pick up pollen

from a flower. They then transfer the pollen to other flowers as they continue looking for more nectar.

Cleanliness is truly a work of art! Some birds, like herons, have small feathers called powder

down that they crush with their beak and feet to rub into the normal feathers and keep

them conditioned. This powder down may also help control feather parasites like mites.  

At the base of the tailbone for most birds, there lies an "oil duct."  Birds will rub their faces

on this duct releasing precious oils for cleaning, preening, and insulating.

To aid in digestion, many fish eating birds eat their own feathers to line their digestive area.

This helps to protect the bird from sharp fish bones.

Nest construction is another amazing use of feathers. Many birds line their nest with bird feathers,

and especially water birds. This helps to keep the eggs warm and offer soft padding.

Some birds like parakeets and lovebirds, actually use the feathers located on their bottom and lower

back to tuck in grass and leaves to use to build a nest.

Water transportation is utilized by adult birds when raising

eggs and baby chicks. Parents will soak their feathers on their

belly before returning to the nest. They can then use the

water to keep the eggs from drying out or to offer their chicks a drink.

Some birds that live in the desert like the sandgrouse have special belly

feathers that are very good at holding water so that they do not have to nest close to

water holes where there might be predators.

​​​Vanity, Beware, Alarm, Comfort!  Visual signals are sent to potential mates, mates, and rivals,

by use of  feather color and patterns.  Feather position is used to communicate a myriad of emotions

from fear, showing off, impressing, and challenging.

Camouflage has many patterns. To keep from being seen by predators many birds have

feathers that look like dead leaves or other parts of their surroundings they live in so that

predators cannot see them. Ptarmigans will change to mostly white in the winter to help camouflage itself in the whiteness. Some predators also like to blend in so that their prey

may come closer to be more easily caught.