1 4 THE NESTS AND EGGS OF BRITISH BIRDS. 



daw-like manner, uttering their noisy and distinctive 

 cries. One cavity sometimes contains several nests. 



Range of egg colouration and measurement : 

 The eggs of the Chough vary from four to six in number, 

 and range in ground colour from white, with a faint tinge 

 of blue or green, to creamy-white, blotched and spotted 

 with various shades of brown and gray, and with under- 

 lying markings of violet-gray. Sometimes a few dark 

 brown streaks or scratches occur, usually on the larger 

 end. In the size and distribution of the markings they 

 vary considerably, some having them large and bold, 

 and arranged in a mass or zone round the largest portion 

 of the shell ; others are more regularly spotted over the 

 entire surface, and in this type the colour of the marks is 

 paler. Another type has few markings, but bold and 

 large, and scattered here and there over the entire surface. 

 Average measurement, i"5 inch in length, by ri inch in 

 breadth. Incubation, performed by both parents, lasts 

 from seventeen to eighteen days. 



Diagnostic characters : The pale ground colour 

 and comparative indistinct definition of the markings 

 are the most important points of distinction characterizing 

 the eggs of the present species. They are most likely 

 to be confused with eggs of the Jackdaw ; but the two 

 species do not breed in company. 



