NON-INDIGENOUS BRITISH BIRDS. 255 



with dry grass and other vegetable refuse. As soon as 

 their breeding haunts are invaded, the old birds rise and 

 fly to and fro with noisy clamour, rarely, if ever, remaining 

 on their nests until closely approached. 



Range of egg colouration and measurement: 

 Tile eggs of the Black-tailed Godwit are four in number. 

 They are pyriform, smooth in texture, and vary from 

 olive-brown to olive-green in ground colour, spotted and 

 blotched w^ith darker olive-brown, and with underlying 

 markings of pale brown and gray. The markings as a 

 rule are somewhat pale and ill-defined, but types occur 

 in which they are bolder and clearer. Average measure- 

 ment, 2*15 inches in length, by rs inch in breadth. 

 Incubation is performed chiefly by the female, but the 

 duration of the period is unknown. 



Diagnostic characters : There is no constant 

 character by which the eggs of this Godwit can be dis- 

 tinguished from those of the Bar-tailed Godwit. As the 

 latter are far and away the rarest, great care should be 

 exercised in their identification. The breeding range 

 of the two species does not impinge, that of the Bar- 

 tailed Godwit being above the limits of forest growth in 

 the Arctic regions. 



