Some Like It Cold: Long-Term Assessment of a Near-Global Invader.

Long-term studies depicting the multicontinental invasion trajectories of species are often constrained by the scarcity of documented records, especially for invertebrates. The red swamp crayfish, (Decapoda: Cambaridae), stands out as an uncommon example of hypersuccessful invasive species with a well-known invasion history at both regional and global levels. This allows for the use of its records to track distribution dynamics and bioclimatic preferences over time. Through multiple temporal comparisons, the global bioclimatic tendencies of the species have been explored over a period exceeding a century (1854-2023) using linear models with generalized least squares estimation and two-sample t-tests. This specific setup provides a rare focus on biological invasions at both broad temporal and spatial scales. The results highlight climatic trends in the invasion process of the species, including decreases in the values of bioclimatic variables associated with temperature and precipitation. This trend encompasses not only mean values but also both extreme (minimum and maximum) and is coupled with increases in elevation and aridity values in the areas with the presence of the species. The findings indicate that the species can engage in new ecological interactions and further affect range-restricted species in climatic refuges once considered protected. These findings help anticipate changes in the species' invasion trajectory, suggesting possible expansions into colder, less humid climates and higher altitudes. This knowledge supports effective monitoring and early detection for management and conservation efforts.