BLACK TERN. 193 



occurring inland, and must have been occasioned by 

 some very peculiar accident. The weather had been 

 rather stormy and unsettled for a week or two pre- 

 vious, attended by a good deal of wind from S. and 

 S.E. 



BLACK TERN.* 



THESE birds occasionally frequent our fens during 

 the summer months, but not in such abundance as 

 formerly. Immense flocks, however, appeared in 

 Bottisham and Swaffham Fens in the summer of 

 1824, which was a very wet season. Many of the 

 specimens which came then under my observation 

 differed considerably from each other in their 

 plumage, particularly with respect to the colours of 

 the head and throat. These parts, which in the 

 winter are much varied with pure white, generally 

 become in the breeding-season wholly black, or at 

 least of a dark ash-colour like the rest of the body : 

 but in some of these individuals no such alteration 

 had taken place ; the forehead, space between the 

 bill and the eyes, throat and fore-part of the neck, 

 being as white as at other times of the year. Yet 

 this was on the 8th of July, when the season of 

 incubation was going on ; as was proved by our find- 

 ing a nest the same day containing two eggs, which 

 were in a forward state for hatching. This nest was 

 placed on the ground, and about the size of a saucer, 

 quite flat, and composed of roots and dry grass, 



* Sterna nigra, Linn. 



