Meeting Abstract
Optimizing plasticity in behavioral performances requires the abilities to regulate physiological effort and to estimate the effects of the environment. One way to do so is through the use of performance-based feedback, which occurs when an individual adjusts behavior according to feedback from prior iterations of the behavior. To describe how performance-based feedback may regulate recursive or continuous behaviors, I developed two models, one (environmental feedback) that assumes an initial ability to regulate effort but not to predict the effects of the environment and the other (effort feedback) that assumes an initial ability to predict the effects of the environment but not to regulate effort. The models produce opposite predictions for how an individual should modulated performance based on feedback from a previous performance and should therefore be readily distinguishable when subjected to an experimental manipulation of feedback. I conducted such a manipulation using an egg-substitution experiment in wild, free-ranging Lincoln’s sparrows (Melospiza lincolnii) and discovered that females adjusted the size of their clutches’ third-laid eggs in a directly proportional response to the size of an experimentally substituted first-laid egg. Moreover they did so in the manner consistent with the environmental feedback model but not with the effort feedback model. Thus, results support the hypothesis that a female bird modulates the size of an egg according to feedback from a previously laid egg on the cumulative effects of the environment. The models call for tests in other systems in order to assess their generalizability. Such feedback-based regulation may not only help female birds maximize net benefits of egg production, it also may be a basis for regulating a wide range of other behavioral performances as well.
