POND, LAKE, AND STREAM 29 



blue above, but dusky white below, with a white, crescent- 

 like frontlet. 



Watch either the Cliff or Barn Swallow build its nest. 

 Tell how they do it and what material they use. After the 

 eggs are hatched, watch the parents feed the young. Do 

 both parents feed them ? How often do they return within 

 an hour ? Are the swallows as wild as the Great Blue 

 Heron ? Do they seem to love the neighborhood of man ? 

 Why? 



Early in August the swallows begin preparations for leav- 

 ing this part of the country. They assemble in large flocks; 

 at night they roost on trees. Willow thickets near lakes 

 and streams seem to be favorite places. In the summer of 

 1895 I found thousands of them roosting in a willow thicket 

 on a small island in the Des Moines River near Windom, 

 Minn. Where have you seen them assemble in the day- 

 time? About August 20 they have generally left. Why 

 should they leave so early ? The herons do not leave until 

 the middle of October, and wild ducks are often here as late 

 as November. Why ? 



Do you know the Purple Martin and the Tree Swallow ? 

 Do you know 011 what the Chimney Swift and the Night 

 Hawk live ? How do they catch their food ? 



18. The Blackbirds. 



MATERIAL : Picture of bobolink or mounted bird ; similar material 

 for different species of blackbirds ; nest of some blackbirds showing 

 how it is fastened to reeds or twigs ; some warbler's or sparrow's nest 

 with one or two cowbird eggs in it. 



Who is not familiar with the Blackbirds ? A merry tribe 

 they are indeed ; flying about, singing, scolding, wooing the 

 whole summer day ! Everybody knows the large Purple 

 Grackle, or Crow Blackbird; the Red-winged, and the Yel- 

 low-headed Blackbird. In the nesting season you will gen- 



