WARBLERS. 497 



first discovered its eggs, of which he gives the following account : — " As we 

 were walking along a little bird started up near us, and began most persistently 

 to utter the alarm note of the yellow-browed warbler, a note which I had learned 

 in Gaetke's garden in Heligoland. As it kept flying around us from tree to tree 

 we naturally came to the conclusion that it had a nest near. We searched for 

 some time unsuccessfully, and then retired to a short distance and sat down upon 

 a tree trunk to watch. The bird was very uneasy, but continually came back to 

 a birch-tree, frequently making several short flights towards the ground, as if it 

 were anxious to go into its nest but dare not whilst we were in sight. This went 



ICTERUiE WARBLER (§ nat. size). 



on for about half an hour, when we came to the conclusion that the treasure we 

 were in search of must be within a few yards of the birch-tree, and we again 

 commenced a search. In less than five minutes I found the nest with six eggs in 

 it. It was built in a slight tuft of grass, moss and bilberries, semi-domed exactly 

 like the nests of our willow-warblers. It was composed of dry grass and moss 

 ends lined with reindeer hair. The eggs were very similar in colour to that of our 

 willow-warbler, but were rather more spotted and smaller in sLze. The yellow- 

 browed warbler occasionally straggles into Europe on the autumnal migration. 

 The adult male has the upper-parts olive-green; a well-defined narrow greenish 

 yellow eyestripe extends over the eyes ; the wing-coverts are tipped with yellow 

 forming two bars across the wings, the wing quills and tail are brown, the lower- 

 parts white suffused with yellowish green. 

 vol. in. — 32 



