154 Mr. A. B. Brooke on the 



is incalculable. They are also very fond of lizards ; and the 

 crop of one which I killed in March was crammed with their 

 remains, both large and small. 



22. ASTUR PALUMBARIUS. 



Very common. One day, when stalking Moufflon, I came 

 suddenly upon an old female in a wild rocky gorge, engaged 

 picking a Woodpigeon she had just killed ; instead of leaving 

 it, as I expected, she gave one look of defiance over her 

 shoulder, seized it in her claws, and dashed off down the 

 mountain, gliding and steering her way through the thick 

 forest in the most marvellous manner. Another, a young 

 male, which I shot, was on the point of taking a three-quarter- 

 grown rabbit. This bird had the remains of a Short-toed Lark 

 (Calandrella brachydactyla) in his stomach. Two males weighed 

 respectively 1 lb. 6 oz. and 1 lb. 4 oz. I mention these ap- 

 parently insignificant details, as I believe that all facts tending 

 to show that permanent differentiation of form that has been 

 effected by isolation consequent upon an island life (even 

 though that differentiation consists in many instances in a 

 large change as to size accompanied by but slight changes of 

 coloration) may lead, if carefully recorded and followed out, 

 to fresh light being thrown upon some questions of the 

 highest zoological interest. 



23. Accipiter NISUS. 



Not very common, and I have only observed them during 

 the winter. 



24. Circus ^eruginosus. 



Very common about the plain ; and round the neighbour- 

 hood of Oristano these Harriers swarm. A nest I found in 

 the end of April was built in the middle of a reedy marshy 

 lake, placed halfway up the stems of the reeds, just clear of 

 the water; the bottom was formed of rough coarse sticks, 

 and the interior of dried matted rushes, in some cases with 

 their roots attached, the egg lying carelessly in the middle. 

 Out of all the numbers that passed under my notice, I never 

 observed any, excepting in the dark brown plumage with the 



