Fantastic Feathers

photography of small blue and brown bird
Feathers: A flash of color and so much more! Photo by Tina Nord on

Feathers, being unique to birds, are one of the most remarkable structures in nature.  They are the ultimate multi-taskers.  Here are some fun feathery feats:  Feathers provide thermoregulation since birds can adjust each feather position at will with the use of specialized muscles.  Feathers are important for protection, camouflage, waterproofing and streamlining.  Feathers are spectacularly colorful and ornamental, having been used as human body decoration for centuries; however, they look much better on the birds.  Feathers make flight possible and that allows birds to exploit the sky over vastly different habitats such as arid deserts, frigid arctic climes and open oceans.

Here are some fun feathery facts:  The number of feathers range from about 940 on a ruby-throated hummingbird to 25,000 on a tundra swan (wonder who counted them).  “Light as a feather” is accurate, although feathers account for as much as 15% of a birds total body weight which can be about twice as much as its skeleton.  Feathers tell a lot about individual birds.  They are how birdwatchers identify species, age and sex. Potential mates use feather color and quality as indicators of fitness.

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focus photography of flying hummingbird
Get your magnifying glass: can you count all 940 (ish) feathers? Photo by Frank Cone on

There are more fantastic fun feather facts.  Researchers have demonstrated that birds exhibit growth bars on their feathers which appear much like tree rings.  Each bar represents 24 hours of growth over the 2-4 weeks that it takes a feather to grow.  Growth bars are like a dieter’s diary, being narrow when food is scarce and wider when plentiful.  This biological bar-code is called “ptilochronology” which literally means “study of feather time”.  Ptilochronology can also be employed to measure habitat quality.  Scientists compared growth bars from a species of bird living in 4 different types of habitats.  Birds that lived in the most disturbed habitats that were sprayed with insecticides had the narrowest band indicating that they were finding the least amount of food. 

Another team of scientists is decoding an invisible feather message by using isotopes.  Isotopes are stable forms of the same chemical element but with a different atomic mass.  It is known that the exact isotopic composition of rocks, plants and soils varies predictably from region to region.  This variation becomes evident in the feathers when a bird eats an insect that fed on a tree species that grew in a particular soil type.  This enables scientists to sort populations of migratory birds over vast geographic ranges by matching northern populations to their southern wintering grounds.  Once critical habitats are identified for declining species of birds, then priorities can be set for habitat protection, thus bolstering conservation efforts.

adorable bird sitting on tree branch in winter forest
“Stop staring at my feathers!” Photo by Skyler Ewing on

Other scientific teams have studied the pollution record found in bird feathers.  Bound up in each feather structure is a record of the bird’s exposure to heavy metals and other dangerous pollutants.  In these experiments breast feathers from young birds still in the nest were analyzed. That way the only food that could have been eaten was that collected locally, so only local contamination would be measured. 

So there you have it:  A fantastic flurry of feathery fun facts and feats!

Please note:  It is illegal to possess the feathers of migratory bird species without the proper state and federal permissions (1918 Migratory Bird Treaty Act).  Enthusiasm for birds and feather study is encouraged but please do so responsibly.  Conduct your hands-on exploration by taking photographs or making sketches, record measurements, and write notes in a journal to admire your feather finds.

If you enjoy our feathered friends at Iroquois National Wildlife Refuge, consider becoming a member of FINWR, or making a donation in support of our Cavity Nesting Bird program! Click here to read more about our Cavity Nesting program.