170 Dr. J. E. Duerden on the 



and run a short distance with the head just skimming the 

 ground, and then raise themselves with a sudden jerk and 

 resume spinning. Occasionally during the day a troop of 

 adult birds, it' slightly disturbed, will make a short start 

 forward and then commence the same circling movements. 

 The performance seems always indicative of good spirits and 

 atmospheric freshness, such as one so frequently experiences 

 in the early morning and towards evening. 



The waltzing is undoubtedly a performance of great com- 

 plexity, involving a number of rapid, well co-ordinated 

 movements of all parts of the body, and calls for considerable 

 practice before perfection is attained. Young chicks, a 

 month or two old, succeed in making only incomplete circles, 

 and do this rather clumsily, sometimes stumbling in the 

 attempt, particularly when reversing. But as they become 

 older they perform several complete turns with great facility, 

 though even adult birds will occasionally stumble and break 

 their legs. 



In any individual the waltzing seems to be greatly stimu- 

 lated by the force of example. At first one bird in a troop 

 will dart forward and commence the circular movements, 

 another will follow and begin the same, and then others, 

 until in the end the entire troop will be careering round, 

 mutually encouraged and stimulated in their mad wdiirl. 

 Some will continue until they drop exhausted, or, apparently 

 becoming giddy, will stumble and fall. The phenomenon is 

 only displayed in all its fullness where a number of birds are 

 herded together. It is, however, frequently resorted to where 

 only a few are associated, but it is never so intense nor pro- 

 longed as where the troop is large. 



The behaviour is without doubt truly instinctive, though, 

 as in many other instincts, it is greatly encouraged by 

 example and perfected by experience. It usually begins to 

 show itself when the chicks are several weeks old, and that 

 it can be initiated without any previous training or example 

 was shown by three chicks under my own care. These were 

 taken from the parent birds when only a week old and then 

 reared by hand, far away from all other Ostriches. It was 



