Developmental environment affects risk-acceptance in the hissing cockroach, Gromphadorhina portentosa.

Abstract

Consistent individual differences in the tendency to accept risk have been demonstrated in invertebrates, fish, birds, and mammals, including humans. These individual differences have been associated with size, growth rate, survival, and reproductive success. Little research, however, has investigated the effect of developmental environment on individual differences in risk-acceptance. Competing hypotheses offer different explanations of how variation in the quality of the developmental environment affects risk-acceptance in adults. The first hypothesis states that individuals developing in poor quality environments take risks because such behavior is their only means of obtaining adequate fitness returns. The second hypothesis states that individuals developing in poor environments avoid risk because their poor physical condition makes them especially vulnerable to injury or death. We measured several forms of risk-accepting behavior (exploration, foraging, and recovery after disturbance) in male hissing cockroaches (Gromphadorhina portentosa) that had developed in nutritional and social environments of varying quality. Individuals raised on poor nutrition diets exhibited lower levels of risk-acceptance than those raised on high nutrition diets. Risk-acceptance among individuals that developed on poor nutrition diets was negatively correlated with body size. We conclude that quality of developmental environment affects risk-acceptance across behavioral contexts in male hissing cockroaches. Our findings are consistent with the hypothesis that condition-dependent vulnerability mediates the relationship between developmental environment and risk-acceptance.