Long-term population dynamics of an endangered butterfly are influenced by hurricane-mediated disturbance

Effective species conservation requires understanding an organism's population dynamics and natural history, but long-term data are challenging to collect and maintain. As a result, conservation management decisions are frequently made using short-term data which are insufficient to accurately assess population trends in most species. For less-studied taxa, including most invertebrates, inadequate understanding of life and natural history impedes conservation efforts. Long-term studies are highly valuable for improving conservation decisions for target species as they serve as a model for other understudied species. We use mark-recapture data collected over 36 years to examine weather drivers of population patterns for a population of an endangered butterfly, Schaus' swallowtail ( Heraclides ponceana ), and to enhance our understanding of its natural history. We show that the population size of Schaus' swallowtail was highly variable, ranging from under 100 to over 10,000 individuals. Population size was influenced by wind events and population size in the previous year. Population size was lower immediately following high wind events but was positively influenced by high wind events four years prior, with notable population increases following tropical cyclone events. This study reveals the potentially beneficial role of hurricane-mediated disturbance on Schaus' swallowtail populations potentially due to increased treefall gaps and the resulting shifts in plant communities. This remarkable data set represents one of the longest-term studies on a tropical insect and highlights the need for further study of tropical cyclone disturbance on insect populations. • Over a period of 35 years, Schaus' swallowtail population size is stable • Inter-year population is highly variable, ranging from 56 to 11,360 individuals • Tropical cyclones may have short-term impacts but long term benefits to populations • The role of tropical cyclone disturbance should be investigated for other taxa