Thalasseus bergii.
Sterna bergii Lichtenstein, Verz. Douhl., p. 80 (1823) (Cape of Good Hope).
This, the typical form, is separated easily from all others by the pale colour of the mantle, which is also a purer grey with less brown tinge in it. Mathews has gone very carefully into this species in his c Birds of Australia' *. In this he gives three forms as occurring in India: S.b.velox from the Red Sea and occurring as a straggler in India, S. b. bakeri from the Mekran coast etc., and S. b. edwardsi from Ceylon. In my original review of this genus, when writing my catalogue I rejected S. b. bakeri but a further examination shows that this bird has a decidedly stouter bill than velox and must be maintained.
Key to Subspecies.
A. Larger ; wing 340 to 385 mm., culmen 60 to 71 mm.
a. Paler……………….T. b. velox, p. 120.
b Darker……………….T. b. bakeri, p. 122.
B. Smaller; wing 300 to 357 mm., culmen 57 to 70 mm.
c. Darker……………….T. b. edwardsi, p. 122.
d. Paler……………….T. b. cristata, p. 123.
Add new comment