Fantastic Feathers

Source:

Adapted from the Isle Of May National Nature Reserve, Expedition Pack (SNH)

Time

20 -30 minutes to examine the feathers

You will need

• flight feathers
• contour feathers
• down feathers
• petroleum-based oil
• hand lens

Did you know?

Feathers and beaks are made of keratin - the same as our fingernails and hair.

Before the activity

• Contact your local ranger or nature reserve warden and ask for some moulted feathers from seabirds. Particularly ask if they have a sample of eider down to show the class.
• Make sure that none of the class are allergic to feathers

The activity

Gather the group where they can watch seabirds flying, Explain that feathers are amazing! they make birds unique in the animal kingdom. There are four things they are used for.....

Ask for suggestions as to what these might be. Elicit answers by getting the group to look at particular birds.

1. flying (of course!)
2. waterproofing -  (look at shags drying their wings) Do other seabirds do this? What would happen if seabirds got wet through? (they would get too cold & too heavy to fly)
3. camouflage -  (look at guillemots, gulls, razorbills, auks, oystercatchers). What is the predominant colour scheme? (black or grey on top, white underneath). How are these colours an advantage? (when hunting fish from above the birds blend into the sky - which will always be lighter / whiter than the sea). However if they are being hunted from above by predatory gulls or skuas then they are hidden against the darker sea. Also look, if possible, at eider ducks. The female ducks have amazingly good camouflage so that they are 'invisible' when nesting on the ground (they nest in much more accessible places than kittiwakes and guillemots). However the drakes are real show-offs. They are black underneath and white on top! They do not help incubate or rear the chicks they just have to compete with other eider drakes for mates.
4. insulation - See if you can spot any eider ducks. Discuss the words 'eiderdown, downie and duvet (french word for down). Eider down is the warmest and lightest filling for sleeping bags, insulated jackets and duvets etc. All birds have fluffy down feathers which are essential for keeping them warm. Birds are warm-blooded and have to keep their body temperature at about 40^oC (Is this warmer than our body temperature?)  (37^oC)

Feathers have to be kept in top condition by the birds. They spend a lot of time preening - this is essential maintenance time. Each feather is 'zipped' together (see additional information below) and oiled. The oil comes from a gland above the root of the bird's tail. The oil conditions the feathers and keeps seabirds waterproof. Parasites and dirt are also removed by preening. Feathers are replaced at least once a year in a moult, usually after breeding and before migration - when brand new feathers are an advantage.

Back in the classroom

Show the different types of feathers to the group (see additional information below) and explain their different functions.  Show them the parts of the feather and explain how the barbules work (for more information see below). Show them how to unzip and zip a flight feather. Hand out the 3 different feather types to each group and let them test them in 3 ways:

1. Drop each one simultaneously from the same height, which one reaches the ground first? How does it fall, float or plummet?
2. Examine the feathers more closely, try pulling 2 barbs apart and then repairing the gap by zipping them back together. Use a hand lens or microscope to examine the barbules to see how they work. Then draw a feather and label its structure.
3. Put water droplets on the feathers and see what happens. Do the droplets run off any of the feathers? Dab some petroleum-based oil onto a feather and the try adding water droplets again. How do the feathers react now to the water? (the pupils should find that the water now saturates the feather). How could seabirds get oil on their feathers and how would this affect them (they wouldn't be able to stay warm or dry or fly and could be poisoned when  preening while trying to clean the oil from their feathers)

Suggested follow up

The activity Seabird City in this section

Additional Information

 Birds have several types of feathers, each with their own jobs. The main feathers are flight feathers, contour feathers and down feathers.

1. Flight feathers are big, stiff feathers that push the bird through the air. There are three types of flight feathers - primaries which are long, secondaries which are shorter and coverts which cover the base of the other flight feathers. 
2. Contour feathers are smaller feathers which lie flat against the bird's body and head to protect it from the elements while giving it a streamlined shape for flight. In cold weather these are the feathers which are fluffed up (this traps a larger layer of air to increase the insulation value of the feathers. 
3. Down is the tiny, soft feathers which lie against the bird's skin and provide most of the insulation.

Each feather has a central hollow (discuss why?) shaft or quill which supports a flat area either side which is called the vane. Many side branches called barbs make up the vane. Branching from the barbs are two sets of barbules. There are hooked barbules and spoon-shaped barbules .The 'hooks' fit into the 'spoons' and give the feather strength and rigidity to maintain the wing shape in flight. 

Curriculum Links

Science

Age Range

2, 3,4