76 



4. Legs. 



(a) Tibia. (e) Middle toe. 



(b) Tarsus. (f) Outer toe. 



(c) Carpel joint. (g) Inner toe. 



(d) Hind toe. 



IV. Bird Music. 



1. Songs. 



(a) Character of song. 



(b) Call notes; alarm calls. 



(c) Manner and time of singing. 



2. Sexual Differences in Song. 



(a) Compare notes of male and female. 



(b) Relate color to song. 



V. Color of Birds. 



1. Variation of Color. 



(a) With age robin, bobolink. 



(b) With seasons tanager, snow-bunting. 



(c) During moulting and wearing off of feathers. 



2. Color in Relation to Haunts and Habits. 



(a) Protective against enemies quail, sparrow. 



(b) Deceptive to prey owl, hawk. 



(c) Attractive in harmony with leaves and flowers oriole, hum- 



ming bird, warbler. 



3. Sexual Differences. 



(a) Tanager, bobolink, peacock, pheasant. 



Read "The Law Which Underlies Protective Coloration," in "The 

 Auk," New York City, Vol. XIII, p. 124. 



4. Relation of Color to Nesting Habits. 



(a) Location. 



(1) Ground meadow lark, song sparrow. 



(2) Trunks of trees woodpeckers; holes bluebird. 



(3) Branches robin, cat bird. 



(4) Pendant from branch oriole. 



(5) Banks bank swallow, kingfisher. 



5. Form of Nest. 



(a) Open nests thrushes. 



(b) Pocket shaped oriole. 



(c) Basket shaped vireo. 



(d) Dome shaped oven bird. 



(e) Wall pocket shaped chimney swift. 



