REFLEXES, IXSTIX(T, AND UEASOX 433 



instinctively. Tliis may be because all ponies which have not 

 this reflex dislike have been destroyed. The imported horse 

 lias no sucli instinct and is poisoned. NCry few animals will 

 eat any poisonous object with wiiich their instincts are familiar. 

 unless it be concealed from smeU and taste. 



In some cases, very elaborate instincts arise in connection 

 with feeding habits. In the case of the California wfM)dpecker.s 

 (Melanerpcs jormicivorus bainlii) a large number together select 

 a live-oak tree for their operations. Tliey first bor(» its bark 

 full of lioles, each large enough to iiold im acorn. Then into 

 each hole an acorn is thrust (Figs. 267 and :l()S). Only one tree 

 in several square miles may be sele-jted, and when their work i.s 

 finished all those interested go aij-out tiieir business elsewhere. 

 At irregular intervals a dozen or so come b\'.ck with much 

 clamorous discussion to look at the tree. Wiien {\\o right time 

 comes, tliey all return, open the acorns one by one, tlevouring 

 apparently the substance of the nut, and probably also the 

 grubs of beetles which have develoi)ed within. W'iien the nuts 

 are ripe, again they return to the same tree and the same 

 process is repeated. In the tree figured this has been noticed 

 each year since 1891. 



The instinct of selj-defense is even more varied in its mani- 

 festations. It may show itself either in the imj)ulse to make 

 war on an intruder or in an impulse to flee from its enemies. 

 Among the flesh-eating mammids and birds fierceness of de- 

 meanor serves both for the securing of food and for protection 

 against enemies. The stealthy movements of the lion, the 

 skulking habits of the wolf, the sly selfishness of the fox, the 

 l)lundcring good-natured power of the l)ear, the greedines.s of 

 the hyena, are all proverbial, and similar traits in the eagle. 

 owl, hawk, and vulture are scarcely less matters of conuntui 

 observation. 



Herbivorous animals, as a rule, make little direct resistance 

 to their enemies, depending rather on swiftness of foot, or in 

 some cases on simple insignificance. To the latter '-ause thr 

 abundance of mice and mouselike rodents may be attribute*!. 

 for all arc the prey of the carnivorous beasts and birds, and 

 of snakes. 



Even young animals of any species show great fear of their 

 hereditary enemies. The nestlings in a nest of the American 

 bittern when one week old sh.owcl no fear of man, but when 



