RAPID: The role of disturbance in maintaining behavioral variation in native species

Cuny Baruch College, New York NY

Investigators

Abstract

Significant weather events may have long-term effects on populations, but these effects can be difficult to measure due to the ephemeral nature of severe weather. Hurricane Harvey has provided the opportunity to precisely test how populations respond to extreme weather. This study specifically looks at how individuals of a common ant species who are repopulating decimated areas behave. Because recent climate models predict severe storms will become more common, understanding how these events affect the populations of native species exposed to them will become increasingly important to understanding the future trajectory of plant and animal survival and the population health of important species. This knowledge can be used to shape effective conservation and preservation strategies and to protect vulnerable species and habitat. This project leverages the existing interest the public has in how ants respond to flooding, such as fire ant rafting, to help explain how animals respond to extreme weather events. It also provides a foundation for hands-on activities and lesson plans to be distributed to rural Texas schools, including schools associated with citizens of the Alabama-Coushatta Tribe. Last, the researchers on this project have a strong commitment to recruiting underrepresented minorities to participate in this work. The ability to disperse to and successfully colonize new habitats is predicated on a disperser's phenotypic and life history traits. In animal populations, patterns of space use and range expansion are inherently behavioral processes. As such, many animals exhibit distinct morphological and behavioral polymorphisms associated with dispersal and range expansion. However, few studies have focused on patterns of recolonization in populations' native ranges after local extinction events, despite the potential for long-term effects on population demography. This study leverages the unique circumstances created by Hurricane Harvey to ask whether re-colonizers of native, disturbed habitat bear behavioral traits predicted to promote colonization in new, non-native habitats. Using ants of the genus Temnothorax, this study tracks the risk-tolerance and life-history phenotype of colonies recolonizing Big Thicket National Preserve in Eastern Texas after the local extinction event caused by Hurricane Harvey flooding. This is done by tracking the risk-tolerance of colonies re-establishing following floods with a standardized aggression assay. Additionally, colonies are kept in common garden conditions for one reproductive cycle to measure energetic allocation toward reproductive and somatic maintenance; a proxy for life-history strategy. This research provides significant insight into the role disturbance has in maintaining behavioral variation and thus a population's ability to recolonize after an extinction event.