56 



finally excavating the overlying soil exactly in the right place, 

 thereby exposing the curved end of the burrow and its helpless 

 tenant. It would be impossible to give anything like an 

 approximate estimate of the number of grubs that were thus 

 taken by the Rooks ; but it is quite safe to compute the 

 number at 25 per cent., a very high percentage considering 

 the extent of the infested area ; but the Rooks were attracted 

 to this rich feeding ground in enormous numbers, and by their 

 unremitting search for the grubs did more to reduce the devas- 

 tating army than could any human agency. It was during 

 the months of June and July that the Rooks made their attack, 

 and when the larvae had pupated and the flies began to appear 

 these birds left the district for other fields." 



Raven (Corvus corax, Linn.). 



374. Female ; Arenig, near Bala ; 23rd April, 1903. — 1 egg 

 of the grouse, in broken fragments ; a quantity of carrion mixed 

 with sheep's wool ; 1 small bone of a mammal ; bits of moss 

 and other vegetable matter ; 1 pebble. 



Carrion Crow (Corvus corone, Linn.). 



375. Female (incubating) ; Crickleigh, Gloucester ; 23rd 

 April, 1906. — Filled with dung of ? horse or ox containing 

 numerous fragments of the beetles Aphodius fimetarius, A. 

 fossor, and 1 Pterostichus madidus ; 1 grain of maize. 



Summary. — Contained insects of the indifferent and bene- 

 ficial groups and corn. 



Skylark (Alauda arvensis, Linn.) 



376. Male; Dee Estuary; 15th January, 1894. — A large 

 quantity of grass ; a few pebbles. 



377. ? Sex ; Dee Estuary ; 15th January, 1894. — A mass of 

 vegetable fibre (chiefly grass), mixed with turnip leaves ; 2 

 beetles (Helophorus aquaticus) ; large pebbles. 



378. Female ; near Chester ; 2^th February, 1894. — Grass 

 remains of 1 beetle (Staphylinid) ; fragments of brick and 

 quartz pebbles. 



379. ? Sex ; Aldford, Chester ; 22nd March, 1894. — Numerous 

 fragments of weevils (Otiorhynchidae, Curculionidae) ; 1 spider ; 

 imperfect seeds of Polygonum sp. ; fragments of brick ; pebbles. 



