CLASS AVES (BIRDS). 



321 

 Friendly 



species of birds. Are they timid or aggressive? 

 or quarrelsome? Your evidences. 



How do the following differ as to their favorite places 

 of living : partridges ; doves ; wrens ; robins ; woodpeckers ; 

 blackbirds; thrushes; owls; kingfishers? Select one 

 other type that is like each one of these in respect to 

 place of living. 



FIG. 129. Sectional view of a food-box for birds, to aid in winter study. May 

 be put at top of post or hung up by the hook at the side of a tree. It should front 

 south. The nails (see figure) should be frequent enough to prevent the waste of food. 



Make a study of the colors of birds. Do the sexes 

 usually differ in color? In what way? In what ways 

 may these color differences be of value to them? 



Compare the nesting habits of the various common 

 birds of your acquaintance. Compare them also as to the 

 degree of activity and the ways in which they express it; 

 as to the mode of flight; the notes of song; the social 

 instincts, and the like. 



326. Skeleton and General Form of the Body. The 



skeleton, which gives the form to the body of animals, is 

 much fused in the trunk of the birds. The vertebrae 

 are fused, the ribs have stays which bind them together, 



