ADAPTATIONS AXD DISTRIBUTION 



during daylight have been lound beneath rocks or lioards ( l^ragg and Smith, 

 1^43). All of the remainder of the bufos and all species of Scaphiopus are 

 definitely fossorial but some specimens of the toads may be diurnal during 

 moist spring weather, and often at other times. In central Oklahoma this is 

 true particularly of large females of B. cognatus and B. w. tvoodhonsii. In 

 the moister southeastern part of Oklahoma, B. t. anu-ricunits and B. ic. joivlcri 

 are commonly out during daylight, especially in shaded areas. 



The seasonal behavior of these organisms is interesting because it varies 

 not only interspecifically, as is to be expected, but also intraspecifically with 

 age, environmental conditions, and sex. This is especially true of the toads 

 (Bufo) as has been shown earlier (Smith and Bragg, 1943; Bragg and Weese, 

 1942). The young of all of the species of Bufo in Oklahoma tend in their 

 first season to be active and to feed both day and night for several weeks after 

 metamorphosis, the exact time depending upon available moisture and inter- 

 specific differences in behavior. The young of B. cognattts, B. compactilis and 

 B. msidior (all limited to prairies in distribution) remain about the parent 

 pool for some time after metamorphosis and disperse from it only when it 

 evaporates or when they reach an age of approximately two to three months, 

 whichever occurs first. At the other extreme, B. t. amen'ainus and B. w. 

 jowleri disperse from the pool and scatter widely within a week or less; but 

 B. w. woodhousii shows an intermediate condition, the individual young 

 toads wandering gradually away from the region of the pool in moist periods 

 but staying rather close to it if the weather is exceptionally dry during their 

 first two or three months. The movements of young B. punctatus are largely 

 unknown, although I have one specimen taken on a dry hillside during day- 

 time and Jones and Derrick (1939) reported young ones active near a pool 

 in daylight. 



The food preferences and feeding habits of salientians in Oklahoma are 

 imperfectly known. The hylas apparently feed in the trees, probably mostly 

 upon insects. The ranas and the cricket-frogs ( Acris crepitans) eat smaller 

 organisms within their normal habitat, the latter being very adept at catching 

 the insects which frequent the banks of pools and streams. The members of 

 the commoner species of Bufo in Oklahoma show little food selection, except 

 that they very rarely ingest vertebrates (Smith and Bragg, 1949) and this 

 seems to be true also for the adults of most species of Scaphiopus (Bragg, 

 1944). The spotted chorus frog (Pseudacris clar^ii) has been seen jumping 

 among weeds, feeding upon small insects. Members of Ps. strecl{eri more 

 commonly frequent road sides and flood plains searching for ground dwell- 

 ing, nocturnal insects and probably spiders after the manner of toads. 



From limited observations, it would seem that food (arthropods) is so 

 abundant in most habitats during the warmer seasons that little in the way 

 of special adaptations has evolved among these animals. All are alike in the 

 essentials of food preference and methods of capture. What the average indi- 

 vidual eats depends upon availability and relative size of the food object. It 

 should be recalled, however, that toads are more selective than frogs, and 

 that young spadefoots sometimes behave as though certain insects are dis- 



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