THE SEA- FLIERS. 1 79 



THE COMMON TERN. 



The Common Tern {Sterna hirundo, Coloured Plate XXXVIII.), when in its adult plumage, 

 closely resembles the Caspian Sea Swallow, but may be recognised by its inferior size, the grey -colour 

 of the under parts of the body, and by its red feet. In young birds the plumage of the back, like that 

 of the preceding species, is transversely spotted with brown, but the feet are of a yellowish shade. 

 The length of this species is from sixteen to seventeen inches ; of these six and a half belong to the 

 tail, the fork being four inches deep ; the span of the wings is twenty-three inches. It is at present 

 uncertain whether all River Terns are to be regarded as belonging to this speeies or not. Should 

 they be found to do so, their habitat must extend throughout the whole north temperate zone, seeing 

 that they are pretty equally distributed in the eastern and western hemispheres. They are met with 

 more frequently than other Terns in the vicinity of rivers and lakes of fresh water. As these birds 

 make regular migrations, they are only seen at their breeding-places in the summer, appearing during 

 the last days of April or the beginning of May, and in July or August preparing for their departure. 

 They spend the winter in the south of Europe, or in the north of Africa, where at that season they 

 are very common. AVhen on their journeyings they fly leisurely, and at a considerable elevation, from 

 one sheet of water to another, generally following the course of streams and rivers, to which, if 

 pressed by hunger, they repair, in order to obtain food and rest Arrived at their destination, they 

 settle themselves either in the vicinity of the sea, or near fresh water, without seeming to have any 

 decided preference for either. 



The Common Terns arrive in the south of Europe early in May, and progressing northwards, 

 colonising as they go, visit Ireland, Scotland, and some of the adjacent islands. On inland waters 

 the Terns do not congregate in great numbers. On the sea-shore, on the contrary, as the breeding 

 season approaches, hundreds of them collect together and form large settlements. One of these 

 settlements, on the coast of one of the Canary Islands, was visited by Bolle, who gives the following 

 account of what he saw : — " The farther we advanced the more numerous became the flights of such 

 pairs as we had disturbed, until at length we were obliged to proceed carefully to avoid treading on 

 their eggs, so numerously did they lay around us on every side. Scarcely had we begun to collect 

 some of the eggs in our hats and baskets, than up rose the whole multitude of breeding birds into the 

 air, thousands in number, and overshadowed us like a great white cloud. Their shrieks were positively 

 deafening, and the uproar was still further increased by the appearance of some other men at a little 

 distance, who were likewise collecting eggs. From out of the living screen above us, many of these 

 birds seemed to rush right down upon our heads, and these were probably those whose nests lay 

 nearest to the place where we stood, and were consequently in the greatest danger of being plundered. 

 After a little while, we retired to a distance, whence we could plainly see the different pairs, as they 

 returned to their eggs, upon which the females immediately planted themselves, while their faithful 

 spouses took their stations beside them. We did not leave them, however, till we had completely 

 filled all our baskets with eggs, and this we accomplished in less tiian an hour. The men above 

 alluded to, informed us that for a few weeks in the year, the place was constantly resorted to by the 

 inhabitants, who eagerly collected the eggs, and that, nevertheless, the number of birds did not seem 

 to diminish ; the truth of this last assertion was indeed sufficiently evident" It not unfrequently 

 happens that by some sudden flood in the rivers, or heavy storm at sea, the breeding-places 01 

 these Terns are completely inundated, and their eggs consequently destroyed. Should such an event 

 occur early in the season, the parent birds will produce a second brood, but if it happens at a later 

 period, their hope of progeny is at an end. Upon one occasion Naumann had an opportunity of 

 witnessing a fair chase between the Common Tern and the agile Tree Falcon. The Tem did not 



