COLUK AM) PATTKitX L\ AMMAI.h 417 



doubtedly tlie result of ])rcvi()iisly made (rials; tliat is, it has 

 been learned by experience. Now it would obviously l>e of 

 advantage to those species of insects that arc ill-tasliriK, if 

 their coloring and pattern were so distinctive and conspicuoui; 

 as to make them readily known by birds, and once learned 

 easily seen. A distasteful cateri)illar needs to advertise it:: 

 mipalatability so effectively that the swooping bird will recog- 

 nize it before making that single sharp-cutting stroke; or peck 

 that would be as fatal to a caterpillar as being wholly eaten. 

 Hence the need and the utility of warning colors. And indeed 

 the distasteful insects, as far as recogniz{>d, are mostly of con- 

 spicuous colors and patterns. 



Such warning colors are presumably possesserl not only by 

 unpalatable insects, but also by many that have certain sj)ecial 

 means of defense. The wasps and bees, provided with stings 

 dangerous to most of their enemies, are almost all conspicu- 

 ously marked with yellow and l)lack. Many bugs, well defended 

 by sharp beaks, possess a conspicuous color ])attern. 



Numerous other animals l)esides insects also are ])elieved 

 to have warning colors. The Gila monster {11 cinder ma) , the 

 only poisonous lizard, differs from most other lizards in being 

 strikingly patterned with black and brown. Some of the ven- 

 omous snakes are conspicuousl}^ colored, as the coral snakes 

 (Flaps) or coralillos of the tropics. The naturalist l^elt. whose 

 observations in Nicaragua have added much to our knowledge 

 of tropical animals, describes as follows an interesting exanii)le 

 of \varning colors in a species of frog: 



''In the woods around Santo Domingo (Nicaragua) there arc many 

 frogs. Some are green or brown and imitate green or dotul l.vives, 

 and live among foliage. Others are dull earth-colored, and hi'lv va 

 holes or under logs. All these come out onl\- :i1 night to feed, and tliey 

 are all preyed upon by snakes and l)ir(ls. In contrast with these ol>- 

 scurely colored species, another little frog hops about in the daytime, 

 dressed in a bright livery of red and blu<'. Ih' cannot l)e mistaken for 

 any other, and his flaming breast and blue stockings show that )ie diH-s 

 not court concealment. He is very abundant in th<> (lam|) woods, aiul 

 I was convinced he was uneatable so soon as I made his ac<iuaintanco 

 and saw the hajipy sense of security with which lie hopped aimut. I 

 took a few specimens home witli me, and tried my fowls and duck.s 

 with them, but none would touch then). M h<\ . by throwing down 



