BLACK-BILLED CUCKOO 75 



up with the power of one leg, which implies an extraordinary muscular develop- 

 ment. * * * Though born blind and essentially naked, the young black-bill 

 is neither deaf nor dumb, and in proportion to its size it is probably the strongest 

 and most enterprising altricial nestling on the North American continent. * * * 

 Like other nestlings, the cuckoo lies flat, with toes clenched, and holds to its 

 fragile nest with a firm grip. Attempt to remove it, and it is likely to pull its 

 nest to pieces rather than loose its hold; or it may even drag out a fellow- 

 nestling, reminding one of crayfishes or lobsters, in the handling of which one 

 may also get a living chain. Should you succeed in displacing a bird, its claws 

 will rapidly open and close in its desperate search for any object to clasp, for a 

 contact stimulus afforded by any solid body can alone satisfy this strong 

 reflex. * * * 



At the age of about six days the nestling cuckoo has reached that peculiar 

 transitory state which we may call the "quill" or feather-tube stage. * ♦ * 

 Towards the end of this brief and unique stage the behavior of the young 

 bird changes in marked and rapid fashion. It indulges in new attitudes, 

 acquires new call- and alarm-notes, shows fear, and begins those preening or 

 combing movements which are to effect a relatively sudden and altogether sur- 

 prising change in its appearance. * * * 



In one instance the first preening action was noticed on the sixth day ; there- 

 after this kind of activity became frequent, and the bird would comb every 

 "quill" within reach, drawing the mandibles over it from base to apex. Then, 

 with apparent suddenness, at the close of the seventh day the transparent horny 

 sheaths began to give way at their base — instead of wearing off gradually from 

 apex to base in the usual fashion — and were raked off by the mouthful. * * * 

 Fear may become manifest as early as the sixth day, when a frightened bird 

 will sometimes clear the nest at a bound and, seizing a branch with both feet, 

 hold firmly to it. Should it drop to the ground, it can make off with surprising 

 speed. If captured and held, it will emit loud, explosive squeals, than which 

 nothing seems to arouse its parents to quicker attack or bolder measures. Re- 

 place it in the nest, and it spreads its wings, stiffens, and lies flat with every 

 feather-tube on end ; and it will repeat these defensive measures as often as it 

 is touched or disturbed. * * * 



When from seven to nine days old, with half of its feathers unsheathed, the 

 cuckoo suddenly leaves its nest and enters upon a climbing period, which lasts 

 about a fortnight or until it is able to fly. At one of my observation stations 

 I saw three young birds leave their nest in succession, and the procedure in 

 the case of the oldest one was particularly interesting. This bird, which had 

 been sitting in the bright sunshine, for the day was not uncomfortably warm, 

 of a sudden moved to one side of its platform. After having combed off several 

 mouthfuls of feather-sheaths, it sat upright for some minutes and gazed into 

 its outer world. Then, directing its attention to a small branch and ducking 

 its head as if contemplating flight, with a leap it cleared the nest, and, catching 

 hold of a twig, with both feet, it swung free with acrobatic dexterity. In an- 

 other moment it had pulled itself up and was comfortably perched. If such a 

 first perch is placed in the shade and the young bird is promptly fed, it may 

 keep to it for a long time; but it can move about, and should it drop to the 

 ground, it can mount to safety again. 



The vertical position assumed by young cuckoos, probably as a 

 hiding pose, has been noted by several observers, but the following 

 incident reported to me in a letter from Frederic H. Kennard, is 

 quite unusual; he says: "I had just been investigating a big highbush 



