28 



GULLS AND TERNS 



Subgenus Thalasseus. 



64. Sterna caspia Pall. CASPIAN TERN. 



Tail not very deeply forked, the outer feathers pointed, but not much 

 narrowed; bill red, feet black. Breeding plumage : crown and back of 

 head .black; mantle light gray; wings darker gray, the outer quills tipped 



Fig. 48. 



with black. Winter plumage: black of head streaked with white. Young : 

 crown grayish, mixed with black posteriorly ; back and tail feathers with 

 dusky spots. Length : 19.00-22.50, wing 15.00-17.40, bill 2.48-3.10, tail 

 5.30-6.75, forked for .75-1.60. 



Distribution. North America at large, breeding in isolated localities. 



Nest. In hollow in the sand. Eggs : usually 3. 



But for their long wings, slender forms, and forked tails, the Cas- 

 pians, the largest of our terns, could easily be mistaken for gulls. 

 Their flight is quicker and stronger, however, and their black crowns 

 usually conspicuous. They are eminently social in the breeding 

 season, nesting in large colonies, and it is no uncommon sight to see 

 several hundred of them lined up on a sandy lake beach, with the 

 waves rippling in at their feet. After the breeding season they scat- 

 ter out and wander widely over the country. VERNON BAILEY. 



Subgenus Actochelidon. 



65. Sterna maxima Bodd. ROYAL TERN. 



Crest of long pointed feathers on back of head ; tail long and forked for 

 half its length ; inner webs of quills broadly margined with white ; bill 

 orange red, feet black. Breeding plumage : upper parts light pearl gray, 

 top and back of head, including crest, black ; under parts white. Post- 

 breeding plumage : forehead and fore part of crown white. Winter plum- 

 age : white mixed with black on back of head. Young : crown speckled 

 with white and dusky, crest only slightly developed; upper parts and 

 tail feathers with spots of dusky." Length : 18-21, wing 14-15, bill 2.40- 

 2.75, tail 6-8, forked for 3-4. 



Distribution. Coasts and larger lakes of the United States, mainly 

 southward. 



