\D\I-I i\ I COLORA71 199 



n.bably been ;i< omp.i ni.-d on the 

 part of birds by an increasing ability t. di^ riinii 

 their >urroundin 



Warning Coloration. In Btr< tttrast t< the protectively 



colored species, there arc many ii K) vividly colored as 



tremely o>n-pieuou> amid their natural -urjoundiiK' 

 :.m\ Ilemiptera i Ay^r/rv, Mur^niti>n, ( 'oleoptera (NecrophofUS t 

 Lampyrida', ('ocrim-Uida-, ( 'hrysonu lida", Hymenoptera Mutillida-, 

 . and nunuTous caterpillar^ and hut tertlio. ( 'oiispicuous col- 

 '.cin.u frequently though not always associated with qualities 

 that render their possessors unpalatable or offensive to birds or other 

 eneinie-. are advantageous if, by insuring ready recognition, they ex- 

 empt their owners from attack. 



Efficiency of Warning Colors. Owing to much disagreement as 

 t<> the actual value of "warning" colors, several investigators have made 

 many observations and experiments upon the subject. Tests made by 

 offering various conspicuous insects to birds, lizards, frogs, monkeys and 

 other insectivorous animals have given diverse results, according to 

 circumstances. Thus, one gaudy caterpillar is refused by a certain bird 

 oe, or else after being tasted, but another and equally showy cater- 

 pillar is eaten without hesitation. Or, an insect at first rejected may at 

 'length be accepted under stress of hunger; or a warningly colored form 

 warded by some animals is accepted by others. Moreover, some 

 of the experiments with captive insectivorous animals are open to ob- 

 ion on the score of artificiality. 



vertheless, from the data now accumulated, there emerge some 

 conclusions of definite value. Frank Finn, whose conclusions are quoted 

 .d. has found in India that the conspicuous colors of some butter- 

 nainae, Acrcea, viola, Delias eucharis, Papilio aristolochici) are 

 probably effective as "warning" colors. Marshall found in South 

 Africa thai mantids, which would devour most kinds of butterflies, in- 

 cluding warningly colored species, refused Acraa, which appeared to be 

 nly distasteful but even unwholesome; Acraa is eaten, however, 

 by the piedaceous Asiliclac, which feed indiscriminately upon insects 

 .ample, beetles, dragon flies and even stinging Hymenoptera. The 

 masterly studies of Marshall and Poulton strongly support the general 

 theory of warning coloration. 



In this country, much important evidence upon the subject has been 

 obtained by Dr. Judd from an extensive examination of the stomach- 

 contents of birds, supplemented by experiments and field observations. 



