Effect of increased aerial temperature on sex specific foraging behavior in Nucella ostrina

Abstract

Global climate change impacts, including increasing frequency of extreme climatic events and elevated aerial and aquatic temperatures, are predicted to substantially affect organisms, ecosystems, and ecological communities. Species interactions’ are fundamental drivers of ecosystem and community dynamics. Comprehensive climate change assessments demand consideration of both the role of species’ interactions in communities, and modulation of body temperature and thus thermal stress impacts via organism morphology and mobility. Sharp environmental stress gradients and a gradient of emersion time make the rocky intertidal a model system for studying the effects of climate change on communities. In this study we manipulated low-tide aerial temperature to test the predicted effects of climate change on the interactions between a motile predator, the gastropod Nucella ostrina, and its sessile prey, the barnacle Balanus glandula. Nucella ostrina, exhibits periodicity in foraging on Balanus glandula, with maximum foraging occurring during periods of nighttime exposure. Subjecting Nucella to chronic and acute aerial temperature manipulations did not alter the timing or magnitude of a previously documented foraging bout, though asynchrony in the feeding of males and females was observed. Movement of Nucella away from food during low tide exceeded initiation of feeding independent of aerial temperature, suggesting behavioral refuge. Sex specific trends in movement may be the effect of different energetic costs for production of eggs and sperm. These results suggest thermal stress affects male and female Nucella differently, but does not disrupt the tide- specific timing of foraging bouts.