THE COMMON TERN. 39 



the general colour above pearl-grey ; " secondaries narrowly margined with white ; 

 outer primary with a black outer web and a broad streak of very dark grey next 

 the white shaft on the inner web, the rest of the inner web white, except toward 

 the tip, where it is dark ash-grey; inner primaries paler grey, with white 'wedges' 

 and dark grey margins to the inner webs " (Saunders) ; the forked tail with the 

 outer webs of its otherwise white feathers, grey the outermost quills darkest ; 

 bill (its tip dark corneous), legs and feet, scarlet. Length 15 inches; wing xoj , 

 tail 6 ; outer feathers yj ; tarsus '85 ; middle toe with its claw '95. 



This species prefers for its nesting place low lying sandy islands, little above 

 the level of the water, gravelly or pebbly shores, and often bare rocks. The nest 

 is merely a rock depression, or a hollow in the ground, occasionally lined with a few 

 strands of vegetable fibre, dry grass, or sea-weed. 



The " Migration " Committee, in their various annual Reports to the 

 British Association, note many instances " of the irregularity of Terns' 

 behaviour at their nesting places, whether of the Arctic or the Common 

 species ; and perhaps still more markedly in the Little Tern. This unsettled 

 habit is worthy of remark. They often occupy and then abandon their nesting 

 places for apparently no particular reason, for it is not invariably because they 

 suffer persecution, though they are more easily scared than most other sea birds. 

 In the Hebrides there are innumerable places where Terns might breed, having, 

 to all appearance, equal advantages with the selected spots ; and possibly the very 

 fact that they are naturally timid birds causes them to take advantage very 

 frequently of a change of residence. In our "Migration Report" for 1886, we 

 find, for instance, that a flock of Terns arrived at Little Ross, in the Sol way Firth, 

 remained a week and then left. In this case, however, they were of course only 

 resting and feeding, probably without any intention of breeding there ; but in many 

 other cases such movements take place suddenly, almost in mid-summer, or in the 

 middle of their nesting season, the dates of which vary greatly at different stations. 



" For purposes of identification during his cruise in 1887, Harvie- Brown often 

 shot some Terns from a colony, both adult and immature, thereby bringing the 

 whole Tern population close about his ears. He scanned all carefully, then lifting 

 the dead birds carried them to a distance, and by throwing them up in the air, 

 again brought the birds all around him. There need never be any difficulty in 

 bringing Terns thus close enough for identification." This sympathetic or 

 inquisitive habit of the Terns is well known. If one of a flock be shot and fall 

 wounded in the water, its companions immediately circle round in the air, uttering 

 shrill screams and sweeping down close to it every few moments, as if encouraging 

 it to rise. 



