Effects of Early Experience on Substrate Pattern Selection in Rana aurora Tadpoles

Rana aurora tadpoles from laboratory-hatched eggs were reared in artificial habitats to examine the effects of early experience on their response to substrate patterns. Tadpoles reared in featureless environments showed no preference for either square-patterned or striped substrate types. Similarly, tadpoles reared in a square-patterned environment showed no differential response to the two substrate patterns, but stripereared individuals showed a significant preference for the striped substrate. This preference was apparently established during the first 14-17 days in the striped rearing habitat, and continued exposure to this pattern through metamorphosis effected little improvement in this expression of preference. Other experiments indicated that the preference was retained through a period of isolation from the rearing substrate type, and could rapidly be established in old and in young tadpoles. The relationship of these results to the developmental ecology of R. aurora is discussed.