The use of right of ways by primary burrowing crayfishes in the Ouachita Mountains Ecoregion of Arkansas

Roadside ditches can harbor beneficial and detrimental attributes for animal persistence. I sought to determine if roadside ditches could be preferred by two narrowly endemic primary burrowing crayfish species, Fallicambarus harpi and Procambarus reimeri. To investigate this interaction, I collected habitat data, locality information, and tested computer generated habitat models for these two species in the Ouachita Mountains Ecoregion (OME) of western Arkansas in the spring of 2014 and 2015. My first objective was to determine the fine-scale habitat preferences of F. harpi and P. reimeri in relation to their occurrence in roadside ditches. My analysis revealed these species to be habitat specialists, preferring open habitat with a low-herbaceous, wet microhabitat; similar to habitat found in roadside ditches. My second objective was to determine the ability of habitat models to accurately predict the occurrence of these two crayfishes across the OME. To investigate this objective, I used the locality data gained in the first field season to construct species distribution models using the program Maxent. I then used the species distribution model as a guide to sample for both crayfish species across the OME. My analysis revealed that species distribution models, specifically Maxent, are a suitable tool for analyzing and discovering new populations of both F. harpi and P. reimeri. My concentrated search efforts resulted in a documented range expansion of both species in the OME. My third objective was to assess the conservation status of both F. harpi and P. reimeri. Using the locality data that I collected over the two years of study (2014 and 2015), I was able to determine F. harpi and P. reimeri are constrained geographically but relatively stable throughout their range. I discovered new populations of both species, moderately expanding the range of F. harpi (1000 km2). I conclude that the microhabitat of roadside ditches can be beneficial to the persistence of these two narrowly endemic habitat specialists in the Ouachita Mountains Ecoregion in Arkansas