154 



OCEAN BIRDS. 



No. 155. 



COMMON TERN. 



Genus: Sterna. Species: S. hirundo. 



Distribution: 



A common summer resident along the coast. 



Date of Arrival: May. 



Date of Departure: Late September. 



General Plumage: 



111 summer, upper parts bluish gray, long wing feathers white, 

 crown black ; under parts white, lower parts pearly, outer 

 tail leathers grayish, rest of tail white. In winter, forehead 

 and under parts white; immature, upper parts brownish. 

 Bill red, black tipped, feet orange in summer. Bill almost 

 black in winter. Length about 15,00. 



Song and Other Notes: 



Crying, harsh screams. 



Haunts; 



A bird of the ocean and bay, breeding on sandy islands. 



