LIFE HISTORIES OF NORTH AMERICAN GULLS AND TERNS. 311 



fully gliding on their long, slender wings close ; to the surface in 

 search of their finny prey, the tiny minnows, which have followed 

 the advancing tide into the protecting, grassy shallows. It is a 

 pleasure to sit and watch their graceful evolution in their untiring 

 efforts to secure a meal, as they quarter back and fprthi over the same 

 ground again and again, cutting the smooth? surfaces of the water 

 with their razor-like bills, scaling, wheeling, and turning like giant 

 swallows, silently engrossed in their occupation for, which they are so 

 highly specialized.! ,.. • ,> . :•.■.. .1, 



, Sprmff.r—Th$ black skimmers arrive on their breeding grounds 

 on Cobb's. Island janduin its vicinity late in April or early in May 

 bu£ they are Jate breeders. For .several weeks they roam about in 

 large, flocks; or ropst , on ;the sand, bars in masses so dense that they 

 blacken the ground, every bird facing the .wind- When resting 

 or sleeping in such situations they squat closely or sit upon the 

 sand for hpursj but if approached every bird rises to its feet and 

 simultaneously all mount .suddenly into the air, flying straight 

 toward the intruder with a chorus of peculiar barking yelps ; wheel- 

 ing just in time they circle over his head, perform a series of aerial 

 evolutions, now high in the air and again close to the water, until 

 they finally settle again on the sand. Their mating performances 

 show off their marvelous powers of flight to advantage and are 

 most exciting as two or more males give chase to the coveted female. 



The coy one* shooting aslant to either side, dashes along with marvelous 

 speed, flying hither and thither, upward, downward, in all directions. Her 

 suitors strive to overtake her ; they emit' their love cries with vehemence ; you 

 are gladdened by their softly and tenderly enunciated ha, ha, or the hack, 

 hack, cae, cae, ot, the last in the chase. Like the female, they^ all perform 

 the most curious zigzags as they follow in clrfse pursuit, and as each beau at 

 length passes her In succession he extends his wings for an instant, and in a 

 manner struts by her side. (Audubon, 1840.) 



Nesting. — In 1907 I spent the last week in June on Cobb's Island 

 and other islands dn its vicinity where I found several large colonies 

 of black skimmers just beginning their breeding operations. On Pig 

 Island, a low, flat, sandy island, entirely devoid of vegetation and 

 barely above high-water mark during the spring tides, I found two 

 large colonies. They had, chosen for .their, breeding grounds the 

 higher, portions of, the §and flats beyond, the reachof high tides, where 

 numerous qys^er, clam, and scallop shells were scattered; about, (half 

 buried in ;the, sand, among which the eggs were not, conspicuous. 

 Large numbers of little hollows had been scraped put in the sand, but,, 

 «ven aitha,t,,lat@ date, June 24, laying had only just, begun ; two. 

 nests, were, seen .wj.th, one egg each and, pne .with t?wo. eggs, ^Ma^iyof 

 the birds, were already, squatting .on the, empty hollows or were 

 busy with^jtheir^urjtships;.., They were very, spl^tpus, flying out 

 174785—21 21 



