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 



ICTERINE 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 size. 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 



