Resource use by the slenderwrist crayfish, a narrowly endemic primary burrowing crayfish in Arkansas, USA

Narrowly endemic species are usually of high conservation concern. Understanding those species’ habitat and resource needs is critical for effective conservation. The Slenderwrist Crayfish, Fallicambarus petilicarpus, is a primary burrowing crayfish species historically known from an approximately 200 sq. km region of south-central Arkansas, USA. To determine its diet and habitat use, we conducted stable isotope analysis on abdominal tissue from the species and measured habitat variables at field sites visited during 2021 and 2022. Our results represent some of the first available data on long-term feeding in primary burrowing crayfish and support a more herbivorous diet strategy in this species. Our field sampling also suggests the importance of low canopy cover and low vegetation height in habitat selection. During the course of our field work, we identified new populations of Slenderwrist Crayfish, however, those populations do not dramatically expand the known range of this narrowly endemic species. With little evidence for specialized dietary or habitat needs, other explanations must be explored to determine factors limiting burrowing species such as the Slenderwrist Crayfish to extremely narrow ranges.