Find a pair of birds engaged in nest building; robins may generally be found. Learn to distinguish the male from the female in appearance, as well as voice. Notice what materials they are using. Which bird takes the lead in building? What does the other bird do? Does he ever carry material, or does he simply act as escort? Does he ever protect his mate from other birds? Write this out, carefully drawing your conclusions from your own observations. After the young birds have left the nest and have no further use for it, you may take the nest and examine it closely. You will find that while there is a similarity in the nests of the same kind of birds, they differ considerably in the materials of which they are composed. For example, the typical robin's nest consists of straws and hairs plastered together with mud and lined with some soft material, but others have been found made entirely of raveled rope; others of carpet rags. The bird evidently is not guided in this matter by blind instinct, but uses its reason in adapting materials that are at hand. If you are fortunate you may find a pair of orioles building their nest. Place some bright-colored yarn or string in pieces of convenient length where the birds will see them. Some of them are almost sure to be woven into the nest. The oriole's nest may be attached to a limb by two or more cords; if it is, notice how it is prevented from swinging by side ropes. You will find it guyed against the prevailing winds. The oriole frequently ties several twigs together, and so uses these to suspend his nest. Notice the nest pouch; those built near houses are quite shallow; those near forests are much deeper. Can you tell why? _The wings of birds._--Describe the different kinds, as short and round, or long and slender, and the effect of the wing-shape upon the bird's motion in the air. Describe the flights of different birds. _Songs of birds._--Write the syllables which seem to you to express the different songs of birds. Notice the different songs of the same bird. A song sparrow was observed to have twelve different songs. He sang each one several times over, as if each song had a number of verses. Then changing his position, he would sing another. To most ears the robin's song is always the same, but close attention discovers that there are variations. Many birds are genuine musicians and compose as they sing, not having formal songs. _Free description of birds._--Write description of some bird of your acquaintance, noting the following:-- _Its appearance._--Color, gait, flight, size from tip of beak to end of tail, spread of wings. _Its common name._--Why given? _Time of arrival and departure._ _Character._--Is it trustful, or shy and retiring?