CHAP. V Social Life of Animals 73 



chased it, so that it had to make off at once." Of the 

 cranes, Kropotkine notes that they are extremely " sociable 

 and live in friendly relations, not only with their congeners, 

 but also with most aquatic birds." They post sentries, send 

 scouts, have many friends and few enemies, and are very 

 intelligent. So is it also with parrots. ' " The members of 

 each band remain faithfully attached to each other, and they 

 share in common good or bad luck." They feed together, 

 fly together, rest together ; they send scouts and post sen- 

 tinels ; they find protection and pleasure in combination. 

 Like the cranes, they are very inteUigent, and safe from 

 most enemies except man. 



On the other hand, some of the most successfiil carni- 

 vores, e.g. wolves, hunt in packs, and not a few birds of 

 prey (some eagles, kites, vultures) unite to destroy their 

 quarry. Combination for defence has its counterpart in 

 combination for attack. In both cases the collective action 

 is often associated with the custom of posting sentinels, who 

 warn the rest, or of sending scouts to reconnoitre. Pecu- 

 liarly interesting are those cases in which the relatively 

 weak unite to attack the strong ; thus a few kites will rob an 

 eagle, and wagtails will persecute a sparrow-hawk. Kropot- 

 kine has noticed how the aquatic birds which crowd on the 

 shores of lakes and seas often combine to drive oflf intrud- 

 ing birds of prey. " In the face of an exuberant life, the 

 ideally armed robber has to be satisfied with the off-fall of 

 that life." 



Among many animals there is co-operation in labour, as 

 well as combination for attack or defence. Brehm relates that 

 baboons and other monkeys act in thorough concert in 

 plundering expeditions, sending scouts, posting sentinels, and 

 even forming a long chain for the transport of the spoil. It 

 is said that several Hamadryad baboons will unite to turn 

 over a large stone, sharing the booty found underneath. 

 When the Brazilian kite has seized a prey too large for it 

 to carry, it summons its friends ; and Kropotkine cites a re- 

 markable case in which an eagle called others to the car- 

 case. Pelicans fish together in great companies, forming a 

 wide half-circle facing the shore and catching the fish thus 



