10 BlUTISH BIRDS. [vol. xiv. 



notes would seem to indicate that the first laid eggs change 

 colour more rapidly than the later ones. It may be noted 

 in this connection that the first eggs are slightly richer in the 

 light green pigment ; possibly, also, they receive less shelter 

 from the parent bird than the later eggs. 



The usual vocal performance of these Grebes, so far as I 

 was able to determine, is a sort of " ko-wee, ko-wee," repeated 

 at regular intervals. It might be compared to the squeak 

 of a dry wheelbarrow, producing one double squeak at each 

 revolution of the wheel. It is, however, a clearer quality 

 than this comparison might indicate. Each " ko-wee " has 

 a rising inflection and its two syllables are run closely 

 together, with the accent on the last syllable. 



