ADAPTATIONS AND DISTRIBUTION 



types of habitats. Those only partially restricted seem eciually at home 

 in some different environments hut seldom il ever occur in others. 



(4) The habits of the animals tend to vary with their ecological restriction. 

 This is especially true of their reproductive activity. All prairie limited 

 species tend to be more like each other than any of them resemble others 

 which are ecologically unrestricted or which are limited to woodland. 

 Similarly species limited to the woodland-savannah are mostly more like 

 each other than any one of them is to others not so limited. 



(5) It is obvious from the above (4) that even though variations in habit 

 and structure often occur at the same time, habit patterns tend to fol- 

 low ecological restrictions in habitat rather than change of structure 

 during evolution and dispersal. This means that habits may develop 

 differently in closely related taxonomic groups and that deductions con- 

 cerning the habits of one species may not apply to a closely related 

 species; and this is more likely to be the case if the two species in ques- 

 tion are differently restricted ecologically. A single, versatile, wide-rang- 

 ing, and ecologically unrestricted species may even have slightly different 

 habits in two ecological communities, especially if these are widely 

 separated geographically so that breeding individuals from one extreme 

 of the range are effectively isolated from those at the other. Trends of 

 this kind are suggested by leopard frogs, by Biifo w. ti'oodhousn, and 

 by B. cognatus, for example. 



(6) In breeding habits, the Oklahoma frogs and toads fall into three groups, 

 fairly closely correlated with their individual ecological limitations. Each 

 species differs somewhat from all others in the details of behavior, but 

 similarities are discoverable which are termed patterns of breeding be- 

 havior and are to be considered as traits or broad tendencies toward 

 adjustment and adaptation to life in ecological niches. 



(7) These patterns are (a) the xeric pattern, exhibited by all species limited 

 to grasslands, by one species of woodland-savannah (Scaphiopm hiir- 

 terii), and by a few less ecologically restricted forms (Microhyla c. 

 olivacea); (b) the mesic pattern, shown by all other species of the wood- 

 land-savannah, and by the same species limited to ecological islands 

 (Rana catesbeiana, R. damitans); and (c) a mixed pattern intermediate 

 between the other two shown principally by B. w. woodhousii Girard, 

 (ecologically essentially unrestricted over much of Oklahoma) and by 

 R. berlandieri, Ps. tristeriata and A. crepitans (partially restricted to 

 ecological islands). 



(8) The contrasts between the xeric and mesic patterns are the most clear- 

 cut the most closely correlated with life in specific ecological commu- 

 nities. The patterns differ essentially as follows: the xeric pattern is 

 characterized by the following tendencies: (a) use of temporary water 

 only, (b) breeding initiated only by rainfall at proper temperatures (no 

 clear-cut breeding season), (c) calls of males attractive to other males 

 as well as to females, (d) huge breeding congresses and much individual 



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