Feathers Teacher Assessment Sheet

Feathers Teacher Assessment Sheet


Fifteen objects or photos/photo copies comprise the "Grab Bag" book review. Each represents a topic developed in the 15 chapters. Feel free to add more, or "wild card" objects to the bag to give more students an opportunity to highlight points from their reading.

If possible, each student should take part in “grabbing” an object from the grab bag. Once an object is drawn from the grab bag, encourage students to use it to help explain the big ideas in the book. Suggested responses are provided in the table on this sheet.


Object or image

Big idea/Teaching point


Archeopteryx. See book picture, p.20


Archeopteryx (pronounced: ark-ee-AHP-ter-icks) is the historic fossil discovery in 1861 that began discussion on relatedness of birds to dinosaurs, which were themselves a controversial and new concept. Archeopteryx was considered a "transitional" life form from reptiles to birds.


A big contour (flight) feather—large enough so anatomic points can be seen of: vane, calamus, rachis, afterfeather. See book, p. 37.

Bird flight is intimately connected to feathers and the aerodynamics they provide birds. Traditionally, scientists taught that feathers evolved so birds could fly. It was a "Why" focus on feather evolution. Modern thinking changes the focus. It is developmental—it probes how feathers actually develop.


Sinosauropteryx prima. See book picture, p. 49.


Discovered in China in 1996 and first reported in the world scientific literature in 1999, Sinosauropteryx (pronounced sigh-no-sore-AHP-ter-icks) provides the first fossil evidence that dinosaurs had feathers. Its discovery helped support the new thinking that developmental needs drove the evolution of feathers, not the function of flight. Many discoveries since then support the new developmental focus. Its power to predict that they would be found is a strong evidence-based measure of its accuracy.


A tube—could be a plastic drinking straw


This chapter elaborates the five developmental stages of feather evolution, and is based on the idea of a feather as a structure that is a hollow tube emerging vertically from a follicle.


A down pillow/mitten—an item with a label stating it contains down


While structural development drives the evolution of feathers, function remains important. In fact, the author said in an interview he was inspired to write about feathers because they performed so may amazing functions—not just one function. That to him is what makes them miraculous. One key function to understand about feathers are their insulating ability—their power to keep birds warm, and therefore alive in cool and cold temperatures. Down is a specialized form of feather “adapted” to insulation, meaning that it so well contributes to the survival of baby and adult birds that evolution has preserved it. Scientists express that concept of a key adaptive trait vital to survival as being “evolutionarily conserved.”


A copy of the two-panel image of  a Toco Toucan on p. 112, without the caption


This chapter explores another key survival trait feathers provide: cooling the bird in warm and hot temperatures—since their muscles generate a tremendous amount of heat. These images show the cooling mechanism in the toucan.


A note card with the acronym WAIR written on it


The acronym WAIR stands for Wing-Assisted Incline Running. Described on p. 127 of the book, it was coined by Ken Dials, a biology professor in Montana who with his students conducted experiments to help settle the ongoing question: How did flight originally evolve, from the ground up, or from the tree down?  That is, did an ancient feathered organism run with wings out and get a lift that led to flight? Or did this winged creature fall out of a high nest and learn to glide and maneuver? Scientists still debate this as an either/or question. While Dials' experiments with WAIR show that a running, ground-nesting chick flapping its wings can in fact achieve flight, many scientists think it's reasonable that both ground up and tree down play a role in flight.


Toy airplane


The author elaborates on the exquisite aerodynamics of flight and the airfoil that feathers form—and which are then combined in an airfoil of a wing—with help from a skydiving falcon named Frightful. A jump out of an airplane with man and bird shows Frightful flies 242 miles per hour—a record for animal flight. page.135.


Flying machine picture, see book, page 147


As myth, story, and songs of the ages show, humans have long been intrigued with flight and sought to mechanically construct what nature gives freely to birds.


Colored picture of a bird of paradise


Another key function of feathers is their ability to communicate through color, such as breeding displays of bird of paradise, gender identity (red male cardinals vs. fawn-colored females) and life stage (spotted breasts of young robins disappear in adulthood.) Color also can camouflage birds to protect them from predators.


A woman's vintage hat, preferable with feather decoration


While birds use feathers to live, humans have always used feathers, too. The feather trade for fashion decorations took an enormous toll on many species, and cultures across the globe still look to feathers for adornment or ceremonial symbols of power.


Bottle of clear dishwashing liquid

Color is a pronounced trait of feathers—and color vision an amazing trait of birds. They can see a range of ultraviolet shades invisible to humans. Scientists study the physics of feather colors to understand how it arises. Color can be created by pigments, or by mechanical means through the structure of the feather components and their ability to bend light waves. To understand the physics of color, the author conducted an experiment at home in his sink with colorless dishwashing fluid, filling the sink. He noticed small bubbles appeared uniformly white. Big bubbles, however, shimmered with structural iridescence as their surfaces stretched and bent light into rainbow colors.


Toy fish

Humans use feathers for many purposes—as flies to catch trout is one more example. Mimicking their waterproofing prowess is another.


Fountain pen


Humans have valued feathers for many of their miraculous properties throughout history—and pens are one more prominent example. For most of history, humans communicated through writing using a bird's feather as a quill pen. The hollow tube held ink, and then released it to paper upon the application of pressure.


Swimming cap

Scientific investigations often begin with a common question—and this book's investigation of feathers did too: If feathers are so important to bird survival, why don't vultures have feathers on their heads? The long-haired, pony-tailed author learned the answer while examining a dead zebra: its stomach exploded, washing his hair in a putrid spray of stomach contents that took days to eliminate from his hair. Putting a swimming cap on his head first would have protected him—and simulated the vulture's featherless head adapted to a carrion-dependent lifestyle of eating rotten food.





This teacher sheet is a part of the Feathers: The Evolution of a Natural Miracle lesson.

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