Meeting Abstract
During the early stages of development, diet is known to affect the growth of individuals and subsequent quality of adults. Therefore, parents’ dietary choices during provisioning of young may influence fitness of their offspring. With regular biotic and abiotic changes in the environment, parents must adjust their dietary selections to maximize fitness. Many studies have explored the theoretical or lab-based consequences of different diet choices with hypothetical environmental changes, but less often in the field. We took advantage of an accidental human introduction of black solider flies that occurred on our long-term field site in 2015. Our study system includes ~60 breeding pairs of free-living European starlings (Sturnus vulgaris), which provision their young for 21 days before the chicks fledge. We use data from 2 years prior to new prey introduction and 2 years post introduction to understand how diet shifted with environmental change. We also test effects of diet choices on the number (total chicks fledged) and quality of the chicks. Preliminary analysis shows that starling predators were tipulid larva (Tipula paludosa and Tipula oleracea) specialists prior to the introduction: 40-60% of prey items brought back to the nest were tipulids in 2013 and 2014. After introduction in 2015, 65% of the prey items were black-soldier flies, though some individuals persistently provisioned tipulids to their young. We explore the differences in meal content of predators and the effects of the offspring quality and number to understand how changes in the environment affect dietary choices of parents caring for young, and the consequences on offspring.
