Dissertation Research Wetzel: The links between cognitive ability and individual variation in parental behavior

Dissertation Research: The links between cognitive ability and individual variation in parental behavior. Parental care is an important trait that varies considerably between and within species. The study of parental care has contributed to new understanding of the evolution of life history and the ecology of behavior, but many questions remain unanswered. Parenting behavior exhibits a curious pattern in most organisms that have been studied—it shows phenotypic plasticity in response to variable conditions (e.g., time of season, number and age of offspring, and the behavior of other caregivers), yet individuals show consistently different levels of care across these conditions. This proposal will address this mix of flexibility and repeatability by treating parental care as a behavioral reaction norm and testing for a biological basis of individual variation in provisioning (parenting personality) and plasticity in care. One possible reason for individual differences in care is that it is due to differences in cognitive ability. This proposal outlines a study of cognitive ability and provisioning behavior in a wild, established population of house sparrows (Passer domesticus). Preliminary research has found that individual sparrows in this population show consistent differences in parenting personality and have significantly different responses to nestling age (variation in individual plasticity). The proposed research will attempt to understand these results by achieving four goals. First, it seeks to assess the cognitive foraging ability of individual parents using several cognitive tests, including spatial memory, goal-oriented problem solving, and associative learning tasks. Second, correlations among these tasks will be tested to search for evidence of a common and general underlying ability. Third, the proposed studies will assess whether cognitive ability affects the rate of provisioning a parent can provide or the quality of food items brought to the nest. Differences in cognitive ability could also affect individual plasticity in care. The proposed research will measure correlations between measures of cognition and individual variation in reaction norm slope with respect to nestling age. Finally, a definitive test of the role of cognitive ability in parental care will be performed by experimentally increasing nesting demand for food and testing if cognitive ability influences parental response.