COMMON AND ARCTIC-TERNS 75 



The enemies of the species are those of the Terns in general. It 

 is attacked in the air by the faster Hawks, from which it seeks to 

 escape by flying to an immense height, or by rapid twists and turns, in 

 which its insect-catching renders it adept. Montagu, in his article on 

 the black-tern, relates how " in a very hard gale of wind many terns 

 were sporting over the water, when a peregrine-falcon passed like a 

 shot, singled out his bird, and presently coming up with the chase, 

 made a pounce, but the great dexterity of the tern avoided the deadly 

 stroke, and took a new direction. The falcon, by his superior velocity, 

 soon regained sufficient elevation to successively repeat his pounces, 

 but at last relinquished the pursuit." 1 



The eggs are sometimes plundered by the usual egg-robbers, 

 furred and feathered. Mr. Jourdain, again, tells me that the "Harriers, 

 especially the marsh-harrier, will rob outlying nests, or even a small 

 colony, but is at once mobbed by all the birds if it approaches a large 

 colony. ' Furred ' enemies must be very few : I fancy a dog would be 

 driven off in many cases ; only an otter would be dangerous, and that 

 only in the few cases when the nests are on deep water." 



COMMON AND ARCTIC-TERNS 

 [F. B. KIRKMAN] 



In order to bring out more clearly what differences there are 

 between the closely allied Arctic and common-terns, I propose to take 

 these two together, apart from their three British congeners. Too 

 little is known of the roseate-tern to give data for satisfactory com- 

 parison. Such information as we possess is summarised in a separate 

 section. This leaves the little and sandwich-terns. As there is 

 nothing much to be gained by emphasising the points of comparison 

 between them, they are treated separately, attention, however, being 

 drawn in each case to important particulars in which they differ from 



1 Ornithological Dictionary. 



