THE BLACK-TERN 73 



and flying low, contrary to their usual custom when migrating over- 

 land or oversea. 1 



The species breeds in colonies, large or small. Solitary pairs are 

 very exceptional. The nests are built in marsh or fen-land, on the 

 ground, on floating masses of water-plants, sometimes on standing 

 bent and matted reeds, occasionally on water-lily leaves, when these 

 are close and strong enough to bear the nest and its occupants. 

 In Southern Spain Mr. W. Farren found the nests floating in the 

 water insecurely anchored by an occasional thin rush. The disturb- 

 ance of the water caused by his wading in made them bob up and 

 down; one, indeed, was shipwrecked. The material of which they 

 were constructed was scanty, and in the surface scum of the water 

 difficult to see. They were in groups of three or four, the groups 

 being usually a hundred yards or so apart. 



Whether both sexes build is not recorded. The material used is 

 chiefly water-plants, and these are often picked from the surface of 

 the water when the bird is on the wing. The eggs are incubated, 

 according to Naumann, by both birds, and the two to three eggs are 

 hatched after about a fortnight, which is almost certainly an under- 

 estimate. According to the same authority the young remain in the 

 nest for two weeks, and are fed by the parents with insects. They 

 continue to be fed both on the ground and in the air for some time 

 after leaving the nest. The parents show great excitement when the 

 nesting-ground is approached. In Holland Mr. Jourdain saw one 

 strike a boy on the head and pursue him for quite a distance, 

 threatening to strike again, though at the time it had not even laid. 

 Old and young depart, for the most part, in August. Of their intimate 

 home-life nothing seems to be known beyond these few facts. 



Those observers who have noted the bird's habits during its short 

 visits to us most are content merely to record its occurrence at this 

 or that place have provided a somewhat striking example of the 

 necessity for verifying statements made even by great naturalists. 



1 Naumann, Vogel Mitteleuropas, xi. 108. 2 See " Classified Notes." 



VOL. III. K 



