PRELIMINARY CLASSIFIED NOTES 107 



built, and is lined with small flat fragments of bark from coniferous trees and a little 

 down. (PI. LXIII.) R. F. Tomes records a nest in which the superstructure consisted 

 of dead couch grass. Both sexes share in collecting material (H. S. Davenport). 

 The depression for the eggs is somewhat slight, and the upper surface of the nest 

 flattish. The eggs are usually four or five to six in number, but clutches of seven 

 and even eight have been several times recorded. They are laid on alternate 

 days, and by removing one at a time as laid the number can be increased to fifteen 

 or sixteen. In colour they are bluish white, sometimes very boldly blotched with 

 rich, dark chocolate-brown, sometimes only lightly mottled or smeared with cloudy 

 markings of reddish brown and purplish. There is often considerable variation 

 among the eggs in a single clutch, and it is not uncommon to find one or more 

 very lightly marked eggs even in a heavily marked set. Average size of 100 eggs, 

 1-52 x 1-26 in. [38'7 x 32-1 mm.]. Incubation is performed almost entirely by the 

 female ; the male has, however, been shot from the eggs, so that apparently he 

 takes a small share in the work, unless his presence was due to some accident to 

 the female. Older writers estimated the incubation period at about three weeks, 

 but closer observation has proved this to be erroneous. Mr. S. E. Brock puts it 

 at 30-32 days, and Dr. J. H. Salter at 37-38 days, but in the case of nests watched 

 by Messrs. E. W. H. Blagg, J. H. Owen and myself the period was as nearly as 

 possible 35 days, which may be taken as the average. The first eggs are occasionally 

 laid towards the end of April, but more commonly in May, and full clutches may 

 be found from the first to the fourth week in May, but generally about the middle 

 of the month. Only one brood is normally reared, but a second clutch is laid 

 if the first is taken. [F. c. E. J.] 



5. Food. Young rabbits, rats, mice, lapwings, thrushes, finches, frogs. 

 The young are fed on small birds and mice (see p. 108). [w. p. p.] 



The following subspecies are described in the supplementary chapter on " Rare 

 Birds": 



Goshawk. Accipiter gentilis gentilis (Linnaeus), [Astur palumbarius 



(Linnaeus)]. 

 [American-goshawk, Accipiter gentilis atricapillus (Wilson).] 



