22 
CASPIAN TEEN. 
greater and lesser wing coverts, blue grey; the first four, 
five, or six primaries are slate grey, with a brown tinge, 
the shafts white; greater and lesser under wing coverts,, 
white. The tail, which is only slightly forked, is grey, 
according to Sir William Jardine; under tail coverts, white; 
the legs, bare of feathers for nearly an inch above the knee 
joint, are as the toes, black; claws, strong and curved, black;, 
webs, black. 
The female is not quite so large as the male. 
The young are at first covered with white down. Before 
their first autumnal moult they have the bill dull red, the 
tip black; forehead and crown, white; chin, throat, and 
breast, white; back, greyish brown, with some bars and 
patches of a darker brown or blackish; greater and lesser 
wing coverts, also greyish brown, with marks of a darker 
colour; primaries, dark blackish brown. Greater and lesser 
under wing coverts, white. The tail is dark blackish brown 
at the end. 
Besides the autumnal moult, the Terns change part of 
their plumage in the spring. 
