BIRD-STUDY 85 



Birds' feet. Draw the foot of the duck, built for 



Compare the foot of the grebe. Why are the legs placed so far back? 



Draw the foot of the hawk, especially fitted for 



Draw the foot of the gallinule, coot, or rail. What other birds have such 

 feet as the rail ? What kinds of legs have they as a rule ? Draw the 

 foot of a chicken or turkey. Examine the foot of a turkey or of a 

 chicken when it has been cut off. Is it closed or open ? When you pull 

 on the tendons, the white cords at the cut, what happens ? In the living 

 animal muscles work these tendons. Would it require effort on the part 

 of the bird to grasp its perch or to let go ? How would this be an advantage ? 



The wing. Draw in outline one of the main wing feathers, a wing 

 primary, from the wing of chicken or turkey. It consists of (i) the quill 

 and (2) the vane, the latter made up of (a) the shaft and (b) the web. 

 Is the web equally wide on both sides of the shaft ? If you were to cut 

 across the wing primaries as they lie in the wing, the cut of the shafts might 



appear something like this (Attach lines to these dots 



to show how the web of each feather would lie.) A bird flies by beating 

 the air with its wings. But when the wing has arrived at the end of the 

 downstroke it must carry back again to begin the next. Why does not the 

 upstroke undo all the lifting effect of the downstroke? Watch birds to 

 see if the downstroke is more rapid than the up. 



FIELD KEY TO CHICAGO BIRDS 



To use a key of this sort when you are trying to identify a bird that 

 you see in the field, read through the description of the several groups 

 lettered A-i, A-2, etc. Select the one that fits the bird under observation, 

 then read under this heading the characters of the several alternative 

 groups lettered E, EE, etc. Such alternative groups always stand under 

 each other in line at the same distance from the left-hand margin of the 

 page. Continued selection narrows down the choice until the final one 

 leads to the name of the bird. 



The several major groups from which selection is to be made in the 

 order of their occurrence are as follows: 



A- 1. Ducks or ducklike birds with characteristic throbbing flight. 

 A-2. Birds of soaring flight usually seen on the wing: gulls, terns, hawks, 



buzzards, swallows, swifts, etc. 



A-3. Birds with feathered rosettes around the eyes: owls. 

 A-4. Birds conspicuous for their long necks and long legs: herons, rails, 



sandpipers. 

 A-5. The woodpeckers. 



