Effects of information load on response times in frogs and bats: mate choice vs. prey choice

Decisions tend to become more challenging as the number of available options increases and choice sets become more complex. Choosing between multiple options may require additional information processing time and effort. Here, we asked if response time increases with stimulus number and attractiveness by female frogs (Physalaemus pustulosus) and their predators, frog-eating bats (Trachops cirrhosus), when comparing the mating calls of male túngara frogs. We found that frogs’ response time is significantly longer when presented with two calls, compared with one. Bats also take longer to respond when presented with two calls but only when they were complex calls. Although the frogs and bats behave somewhat similarly in this experiment, the decisions that these animals are making are occurring in different domains (mating vs. foraging) and have different fitness consequences. Given these differences, we find it especially interesting that for both frogs and bats, we see similar temporal patterns in response times as a function of information load. SIGNIFICANCE STATEMENT: Animals are often faced with several options simultaneously. One cost of decision-making is the time involved in choosing the best option within a choice set. Here, we asked whether female frogs and frog-eating bats take longer to respond when presented multiple frog mating calls simultaneously. We also asked whether the attractiveness of those frog calls influences the time it takes frogs and bats to respond to them. We found that the time to respond was influenced by both the number and attractiveness of frog calls for both bats and frogs; however, frog response time seemed to be more greatly influenced by the number of frog calls, while bat response time seemed to be more influenced by the attractiveness of frog calls. In general, our results suggest that there may be similar mechanisms involved in decision-making for both animals.