1887-88.] The Rook. 125 



Eecurring to rooks feeding in the garden, it is in such cir- 

 cumstances that their shrewdness and forethought obtrude 

 themselves on our attention. Several cats were in the habit 

 of appearing as soon as the food was thrown out. The rooks, 

 by their noise and attitude of offence, proved themselves able 

 to keep the cats at bay until their appetites were fully satis- 

 fied, when, on their leaving, the cats picked up the remaining 

 food. On the rooks discovering this, it was an interesting 

 study to observe them, as, after having satisfied themselves, 

 they picked up pieces of the remaining meat and carried them 

 off to different parts of the garden, where they carefully buried 

 them in the earth. During the afternoon they regularly re- 

 turned, and with unerring accuracy disinterred the pieces of 

 meat buried in the morning. 



The reflective instinct exhibited by the rook is proverbial, 

 and developed to a larger extent than in most other birds. 

 Its powers of arithmetical calculation have long attracted the 

 attention of naturalists. It has been found that they can 

 count numbers accurately up to three inclusive, but that this 

 is the limit of their capacity of calculation. This peculiarity 

 in the rook has been discredited by many, but, when tested by 

 experiment, has been again and again verified. For example, 

 wheiT they are so pressed for food during a snow-storm as to 

 visit a stack of grain, let a place of concealment be extem- 

 porised by branches of trees or other material within easy 

 shot, where watchers can successfully conceal themselves. If, 

 after being repeatedly fired at from the ambush in question, 

 the rooks discover one,, two, or three persons betake themselves 

 to the place of concealment and leave at intervals, it will be 

 found that they will not descend to feed until the last of the 

 tliree has left. But should four or more persons place them- 

 selves under cover, it will be found that after the third has 

 left their sense of danger disappears, as will be seen by their 

 beginning to feed with apparent security. I am not aware of 

 this peculiarity being possessed to the same extent by any 

 other bird. 



I have several times been much interested in observing the 

 ingenuity displayed by rooks in extracting grease from the 

 grease-box above the wheels of railway-waggons. Perching 

 at the side of the wheel, and placing their necks awry, they 



VOL. II. I 



