"Many birds, including practically all members of the parrot tribe, many of the crows and jays, as well as mynas and starlings, learn to repeat sounds, words and sentences. Ability varies with both species and individuals. Certain species show greater aptitude as a whole than other species, while there is a great difference between individuals of the same species. "Gray parrots are generally considered the most intelligent of their tribe, and are especially apt at imitating sounds, such as running water, whistles, etc. I have one at home which always answers a knock with 'Come in.' Often he furnishes the knock himself by pounding the perch with his bill, following it with 'Come in.' Amazon parrots are especially good at tunes, some specimens being able to whistle complicated airs and sometimes sing several verses in a high, clear voice. Both grays and Amazons often talk with great fluency, vocabularies having been reported of as many as one hundred words. Often there seems to be intelligent association of certain acts or conditions with corresponding sentences, these sometimes occurring with singular patness.
"Hill mynahs, of the genus Eulabes, often talk as well as parrots. The common introduced European starling often says a few words quite clearly. I once knew a long-tailed glossy starling (Lamprotornis caudatus) which shared an aviary with an accomplished albino jackdaw. The starling had acquired much of the jackdaw's repertoire, and the 'conversations' carried on between the two birds were most amusing."
A raven in the Zoological Park says "Arthur," "Shut up," "All out" and "Now look what's here" as perfectly as any parrot.
Listed in the order of their ability to learn and remember talk, the important talking birds are as follows: African gray parrot, yellow-headed Amazon, other Amazons, the hill mynahs, the cockatoos, the macaws, and the various others previously mentioned.
It is safe to assert that all migratory birds display excellent powers of memory, chiefly by returning to their favorite haunts after long absences.
Recognition of Persons. Mr. Crandall says there can be no doubt of the ability of most birds to recognize individual persons. This is seen in the smallest species as well as in the largest. He once saw a bullfinch in the last stages of pneumonia and almost comatose, show an instant reaction to the presence of an owner it had not seen in weeks. Many birds form dislikes for individual persons. This is especially noticeable in the parrot tribe. A large male South American condor was friendly enough with two of his keepers but would instantly attack any other keeper or other person entering his enclosure, whether wearing the uniform or not. With his two approved keepers he was gentleness itself.
Parasitic Nesting Habits. In the bird world there are a few species whose members are determined to get something for nothing, and to avoid all labor in the rearing of their offspring. This bad habit is known of the Old World cuckoos, the American cow- birds, the South American rice grackle (Cassidix), and suspected in the pin-tail whydah (Vidua serena). It seems to reach its highest point in the cuckoos. It is believed that individuals lay their eggs only in the nests of species whose eggs resemble their own. Apparently much skill and intelligence is required for introducing parasitic eggs at the most favorable moment. This is equally true of other parasites.
Curator Crandall has taken several eggs and young of the rice birds from nests of two species of giant caciques in Costa Rica, but never saw an adult Cassidix. It is considered a very rare species, but probably is more sly than scarce. Young cuckoos eject unwelcome nestlings shortly after hatching.
Daily contact with a large and varied collection of birds great and small, gathered from every section of the habitable regions of the earth, naturally produces in time a long series of interesting cases of intelligence and behavior. Out of our total occurrences and observations I will offer two that reveal original thought.
Good Sense of the Wedge-Tailed Eagle. In discussing bird intelligence with Mr. Herbert D. Atkin, keeper of our Eagles Aviary and the cranes and water birds in the Flying Cage, he called to my attention two species of birds which had very much impressed him. Afterward he showed me all that he described. Keeper Atkin regards the wedge-tailed eagle, of Australia, as the wisest species with which he has to deal. In the first place, all four of the birds in that flock recognize the fact that he is a good friend, not an enemy, and each day they receive him in their midst with cheerful confidence and friendship. In the fall when the time comes to catch them, crate them and wheel them half a mile to their winter quarters in the Ostrich House, they do not become frightened, nor fight against being handled, and submit with commendable sense and appreciation.