RELATIONS TO ANIMATE ENVIRONMENT 123 



large deposits of their bones indicate that the)' were on the wane, 

 and that natural causes had ah'eady reduced the feathered 

 l)opulation of these islands. A glacial period is believed to 

 have wrought their destruction, and in one great morass, 

 abounding in springs, their bones occur in such enormous 

 numbers, layer upon layer, that it is thought the birds sought 

 the place where the flowing springs might afford their feet at 

 least some respite from the biting cold, and there perished 

 miserably by thousands. 



" What Nature spared man finished, and legends of Moa 

 hunts and Moa feasts still lingered among the Maoris when 

 the white man came and began the extermination of the 

 Maori." 



That these gigantic birds— the largest species being far 

 larger than an Ostrich — owe their final extinction to man there 

 can be no doubt ; for masses of charred bones and egg-shells 

 show that they were hunted for the purposes of food. 



F'urther illustrations of this work of extermination and 

 extinction could be shown, but enough has surely been quoted 

 for the purpose of this chapter, since our aim is more especially 

 to show that birds, by close adaptation to any particular environ- 

 ment, become too highly specialised to respond to any further 

 changes therein, and consequently must die out. Nowhere is 

 this fact more strikingly illustrated than in the case of flightless 

 birds. Here, from an abundance of food procurable on the 

 ground, and freedom from enemies, flight becomes unnecessary. 

 As a consequence, in the course of a few generations the wings 

 have so decreased that flight has become impossible. Should 

 these times of abundance and peace continue, the wings, as in 

 the case of the Moa, vanish completely. The introduction of 

 carnivorous animals now introduces a new factor into this Edenic 

 environment, to which it is impossible to respond further. 

 Return to flight is impossible, and before any devices for avoid- 

 ing or meeting the new conditions can be developed, extinction 

 has overwhelmed the victims. 



