They enjoy society of other birds as well.  In India, the jays and crows come together from many miles round, to spend the night in company with the parrots in the bamboo thickets.  When the parrots start hunting, they display the most wonderful intelligence, prudence, and capacity of coping with circumstances.  Take, for instance, a band of white cacadoos in Australia.  Before starting to plunder a corn-field, they first send out a reconnoitring party which occupies the highest trees in the vicinity of the field, while other scouts perch upon the intermediate trees between the field and the forest and transmit the signals.  If the report runs “All right,” a score of cacadoos will separate from the bulk of the band, take a flight in the air, and then fly towards the trees nearest to the field.  They also will scrutinize the neighbourhood for a long while, and only then will they give the signal for general advance, after which the whole band starts at once and plunders the field in no time.  The Australian settlers have the greatest difficulties in beguiling the prudence of the parrots; but if man, with all his art and weapons, has succeeded in killing some of them, the cacadoos become so prudent and watchful that they henceforward baffle all stratagems.(22)

There can be no doubt that it is the practice of life in society which enables the parrots to attain that very high level of almost human intelligence and almost human feelings which we know in them.  Their high intelligence has induced the best naturalists to describe some species, namely the grey parrot, as the “birdman.”  As to their mutual attachment it is known that when a parrot has been killed by a hunter, the others fly over the corpse of their comrade with shrieks of complaints and “themselves fall the victims of their friendship,” as Audubon said; and when two captive parrots, though belonging to two different species, have contracted mutual friendship, the accidental death of one of the two friends has sometimes been followed by the death from grief and sorrow of the other friend.  It is no less evident that in their societies they find infinitely more protection than they possibly might find in any ideal development of beak and claw.  Very few birds of prey or mammals dare attack any but the smaller species of parrots, and Brehm is absolutely right in saying of the parrots, as he also says of the cranes and the sociable monkeys, that they hardly have any enemies besides men; and he adds:  “It is most probable that the larger parrots succumb chiefly to old age rather than die from the claws of any enemies.”  Only man, owing to his still more superior intelligence and weapons, also derived from association, succeeds in partially destroying them.  Their very longevity would thus appear as a result of their social life.  Could we not say the same as regards their wonderful memory, which also must be favoured in its development by society—­life and by longevity accompanied by a full enjoyment of bodily and mental faculties till a very old age?