Jeremy L. Marshall and Carlos D. Camp 



and parasitic wasps (Scelionidae), were the second most important 

 group, making up 17% numerically and occurring in 32% of the 

 stomachs. Hymenopterans made up 15% of the relative area. Other 

 important insect groups represented were coleopterans, particularly 

 rove beetles (Staphylinidae), making up 8% of numbers, 9% of area, 

 and occurring in 19% of the stomachs, and delphacid homopterans 

 (7, 11, and 14%, respectively). Although found only occasionally, 

 relatively large roaches (Dictyoptera) and walking sticks (Phasmida) 

 made up a considerable amount of the total quantity of food eaten 

 (19 and 10% of total area, respectively). The only non-insect food 

 items found were arachnids. These consisted primarily of mites 

 (Acarina), which made up 9% numerically, 6% of the area, and occurr- 

 ed in 16% of stomachs. 



Juvenile frogs from the 5 June, Grady County sample had a 

 mean SVL of 8.80 mm with a standard error (SE) of 0.21 mm. Adult 

 males from this sample had a mean SVL of 14.87 mm and a SE of 

 0.23 mm. Food items eaten by these frogs are shown in Table 2. The 

 Shannon-Wiener Index for juvenile prey species diversity (//' = 1.062) 

 was significantly larger than that for adults {H' = 0.739; t = 3.27, df 

 = 45, P < 0.01). There was a negative correlation between number 

 of food items eaten and frog size (r 2 = 0.25, t = 2.18, df = 14, P < 

 0.05). 



DISCUSSION 



Pseudacris ocularis is commonly found on lower tree trunks and 

 foliage up to a height of 1 m or more (Harper 1939); males prefer 

 these sites as calling perches (Harper 1939, Mount 1975). However, 

 the majority of food items we found were arthropods that are associ- 

 ated with leaf litter and/or soil (e.g., springtails, mites, dipteran lar- 

 vae, staphylinids, ants, thrips, palpigrades, etc.). In addition, we found 

 a large number of frogs on the ground, particularly during daytime 

 collections. It is apparent, then, that P. ocularis spends a consider- 

 able amount of its foraging time on the ground. 



According to optimal foraging theory (Pyke et al. 1977, Krebs 

 1978), a predator should choose prey that represent the greatest net 

 energy gain and forage in areas where profitable prey are most fre- 

 quently encountered. Considering the small size of these frogs, small 

 abundant leaf litter arthropods such as springtails and mites might 

 represent a relatively stable, predictable source of profitable prey. 

 However, amphibians might find larger arthropod prey to be more 

 profitable than small ones due to a proportionately smaller exoskel- 

 eton (Jaeger and Barnard 1981). Therefore, little grass frogs should 



