Order GAVIE. 
Family LARIDAS. 
Sub-Family STERNINA. 
BLACK TERN. Aydrochelidon mgra (Linneus). 
Coloured Figures.—Gould, ‘ Birds of Great Britain,’ vol. v, pl. 
75; Dresser, ‘ Birds of Europe,’ vol. viii, pl. 592; Lilford, 
‘Coloured Figures,’ vol. vi, pl. 1. 
Less than a century ago the Black Tern was quite a 
common summer-migrant to the south-eastern counties of 
England, where it bred in large numbers; but as in: the 
case of the Ruff and other species, drainage has wrought 
such changes that no longer are these districts used as 
nesting-sites. 
In April and early May,! small numbers make their 
appearance, not only on the coast, but about rivers, lakes, 
and marshes. 
In the northern and western counties of England, this 
Species 1s comparatively rare, but it is met with in many 
parts of the low-lands of Scotland. In the Hebrides and 
Orkneys it is not known. 
Its visits to Ireland are irregular. Examples have 
been recorded from the following counties, chiefly during 
the autumn :—Kerry, Cork, Waterford, Tipperary, Louth, 
Mayo, Leitrim, Antrim, Down, Londonderry, Donegal, and 
Dublin. In the last-named county specimens have been 
most frequently obtained. 
Of the birds which appear in August on the southern 
‘ In the ‘ Zoologist,’ 1901, p. 105, Mr. A. Patterson mentions that on 
May 8th, 1895, he saw forty-two of this species on the mud-flats of 
Breydon, in company with Gulls. On the same date of the previous 
year a flock of thirty was observed. 
