48 BIRDS 



birds rise like a cloud and fly about in majestic circles, 

 screaming peisistcntly until the trespasser leaves. 



Early in June three eggs are laid, varying greatly in 

 shape and color; the background is light green, buffy or 

 drab, spotted and blotched with various shades of brown 

 and lilac. The young are able to care for themselves as 

 soon as hatched. 



BLACK TERN 



The Black Tern, the only dark-plumaged member of the 

 gull or tern family inhabiting the interior portions of North 

 America, breeds from the Gulf of Mexico to upper Canada 

 and from the Atlantic to the Pacific coast, nesting even 

 within the corporate limits of Chicago. 



While gregarious, they are found in smaller groups than 

 most of our long-Avinged swimmers. Largely insectivorous, 

 they capture their prey in the air. They also plunge into 

 the water after small minnows and other marine life. 

 Although the feet are webbed, these birds seldom swim, 

 except, perhaps, when migrating across large bodies of 

 water. Their call note is a harsh shriek, uttered incessantly 

 if one intrudes upon their nesting sites, usually in marshy 

 places, preferably open country free from timber. 



The nests are constructed of decayed vegetation, dead 

 flags, and rushes, often a mere depression on a partially 

 submerged muskrat house, containing two or three dark- 

 yellowish eggs, heavily and tliicklj' blotched with shades of 

 lilac and very dark brown. These birds have a habit of 

 rolling their eggs in the wet earth and vegetation, thereby 

 rendering them less conspicuous. I have known the birds 



