Unpredictable disturbance and its effects on activity behavior and lifespan in Drosophila melanogaster

Animals exhibit natural movement patterns that are important for their survival and reproduction. Human disturbance can alter these movement patterns. In many natural settings, assessing the long-term impact of these altered movement patterns is difficult. Laboratory studies with model organisms may provide additional insight into the long-term effects of altered movement behaviors, such as those caused by human disturbance. Here, we investigate how unpredictable disturbance impacts animal activity and lifespan of Drosophila melanogaster. We selected four strains from the Drosophila Genetics Reference Panel (DGRP) to assess animals with different baseline activity levels. The unpredictable disturbance treatment was simulated using the TreadWheel to administer four randomized 30-min disturbances daily. We found that both 5-day and 20-day disturbance treatments altered activity levels, but the response was dependent on sex, genotype, and age of the animals. While we detected altered animal activity in several groups, lifespan generally was not affected, with a few exceptions. Our results highlight the complexity involved in predicting individual responses to disturbance but suggest that long-term effects on lifespan are rare in response to short-term disturbance.