STERNA BERGII. 
1027 
Young. I have not had an opportunity of examining a nestling of this species. 
Immature, 1st plumage. Wing 12-8 inches ; tail 5-5 ; tarsus 1*12; middle toe T05 ; bill to gape 3-0, at front 2-2. 
Feathers of the back and scapulars with large terminal brown spots ; longer scapulars, tertials, and greater coverts 
brown at the tips, witli a whitish margin ; median wing-coverts marked with paler brown than the back ; the 
lesser series blackish brown, edged with white ; secondaries blackish terminally, the inner webs white ; primaries 
black, tinged with grey ; tail slightly paler, tipped with white ; head and nape blackish brown ; the forehead and 
front of crown whitish, spotted with brown ; beneath white, striped with brown on the sides of the neck, face, 
and across the fore neck ; the upper throat and breast unmarked. The tongue is bluish in the immature bird. 
An example from Bass’s Straits, Australia, younger than the above, has the same general character of plumage, the 
forehead being of course darker, as this becomes pale with age. 
Birds in the second year show their immaturity in the dark band on the ulna adjacent to the edge of the wing. 
An October example in the 2nd year (female) measures — wing 14-7, bill at front 2-65. 
Ohs. This species has been greatly subdivided, owing to local variation in the colour of its plumage and its dimensions, 
a parallel to which we have in many other widely-distributed forms. Hence we have it described from the Cape 
as S. bergii by Lichtenstein, as S. velox from the Bed Sea by Biippell, S. pelecanoides from North Australia by 
King, and, finally, as S. poliocercus (its smallest form) from the south of Australia by Gould. Mr. Saunders has 
rendered good service in examining either the types of these and other races into which the species has been sub- 
divided, or carefully comparing a large series of specimens, including all tbe representatives of the races in 
question, and finally coming to the conclusion that there is but one good species to be made out of them all. 
I have myself looked over a considerable series from various parts of the world, and I can wholly indorse his 
verdict. The main character of the species is the black cap, of similar boundary in all, and the white forehead 
formed by the termination of that cap at a certain distance from the bill. Even in Ceylon there is a considerable 
variation in size and colour ; but fine specimens in good plumage are quite equal in size to those from Africa. To- 
wards China the species begins to decrease in size, and in the south of Australia reaches its minor limit. Examples 
in summer plumage, in the Swinhoe collection from Amoy, measure as follows : — wing 13-1 to 13-4 inches, tail 6-9, 
tarsus IT, bill at front 2-2 to 2-4. A female from the island of Morotai, collected by Bernstein, measures — wing 
13-0, bill at front 2-3, showing a decrease in the wing, but an increase (individual) in the length of the bill. 
Specimens of S. poliocercus in Mr. Saunders’s collection range as low as 12-75 in the wing. Mr. Hume furnishes 
some very valuable data concerning the size of Indian examples ; he found those he procured at the Laccadives 
rather smaller than those from the mainland, the wing-measurement varying from 13-5 to 13-8 ; that of speci- 
mens from various parts of the coast from the Persian Gulf to Tenasserim is 13-2 to 15-12, three fine examples 
from Astolah measuring 14-75, 14-87, 15-12 inches. 
Distribution. — This fine Tern is found all round the coasts of Ceylon more or less throughout the 
year, being, however, most numerous on both sides of the island during the breeding-season, at which 
time it frequents the stretches of coast adjacent to its “ colonies.” They are mostly seen about the coast 
during stormy weather, except in the latter part of the year, when they are very abundant on the rocks near 
Colombo, a large proportion of the flocks seen there being composed of young birds. They appear in consi- 
derable numbers near Galle in the “ Little Monsoon,” or first break-up of the fine weather in April, being 
then driven from the sea towards the shore. During the lull that follows they again go out to sea, and do not 
frequent the shore in numbers until the end of May, at which time they are collecting at the breeding- 
“ colony ” on the rock near Balapitiya. In July I have seen it in the Hambautota district ; and in August 
great numbers frequent the vicinity of the “Basses,” and doubtless are the progeny of some “colony” iu the 
vicinity. At Trincomalie they are common from September until April, but not so abundant as the next 
species. About the shallow waters surrounding the Jaffna islands and on the “ Lake” I do not think they 
are, as a rule, so plentiful as on the exposed and rocky coasts of the island. 
It is found on all the coast of India, but apparently is more abundant on the western side, being a 
common bird on the Malabar coast and near Bombay, and very abundant in the Laccadives, where Mr. Ilume 
considers there must be a breeding-colony at Pere- Mull-Par. On the west coast it is found at Madras pretty 
commonly, but is met with rarely round the head of the Bay and along the coast of Tenasserim, as 
Mr. Hume records it only from the south of Mergui. It frequents the coast of Sindh, Ivurrachee harbour, 
and the Gulf of Oman, breeding in immense numbers on the island of Astolah. It inhabits presumably the 
6 Q 
