LONG-WINGED SWIMMERS 47 



become very noisy, "uttering a grating, monotonous note." 

 It is said that at times, in their frenzy they fly at an 

 intruder, often approaching very close to his head. 



In the winter the plumage of this beautiful tern shows 

 a decided change. The head becomes white, more or less 

 spotted with black; the eye is enclosed by a large black 

 area : the bill becomes black and the feet brownish. 



COMMON TERN 



The Common Tern, often called Wilson's Tern, sea 

 swallow, red shank, summer guU, and mackerel, is often 

 confused with arctic tern and Forster's tern. This beautiful 

 httle sea swallow was first reported by Wilson, one of our 

 earliest ornithologists. Formerly abundant, this bird is now 

 threatened with extinction unless protected from plumage 

 and egg hunters. These terns perform extensive migra- 

 tions, passing the winter months on the coasts of South 

 America, often far below the equator. In summer they may 

 be found breeding on the islands of the Great Lakes in 

 company with herring gulls and Caspian terns. 



The birds are as agile on the wing as our barn swallow, 

 and capture many flying insects. They also feed upon 

 marine life, but refrain from playing the role of scavenger, 

 leaving the gulls to devour any decaying animal matter. 



Hundreds of terns may be found nesting together, 

 depositing their three eggs in a carelessly constructed nest 

 of dry grasses on the pebbly beach or rocky projections just 

 above high-water mark. Quite a commotion prevails when 

 the naturalist intrudes upon their breeding grounds; the 



