Living on the edge: Status of Eurycea lucifuga (Cave Salamander) and Gyrinophilus porphyriticus (Spring Salamander) at the periphery of their ranges in Mississippi, USA

Abstract

The northeastern corner of Mississippi is at the southwestern periphery of the Cumberland Plateau, and
little is known about most of the salamander species in this region. Especially for Cave Salamanders (Eurycea lucifuga)
and Spring Salamanders (Gyrinophilus porphyriticus), much of what we know is based on anecdotal encounters. Both
E. lucifuga and G. porphyriticus are state-endangered in Mississippi and both are considered species of greatest conservation
need. To further assess their conservation status, we completed distribution and encounter-rate surveys during
July/August 2021–2023 in Tishomingo County, Mississippi. For E. lucifuga, we completed 37 surveys at ten caves and
rock-face recesses (total effort: 35.8 person-hours). We made 32 observations of E. lucifuga at four sites (catch-per-unit
effort [CPUE]: 1.5/h), and also opportunistically documented the species along two Hartselle Sandstone rock faces
during a related study of Green Salamanders (Aneides aeneus). For G. porphyriticus, we completed 65 surveys at 36 sites
that included caves, streams, springs/seeps, and waterfall-splash zones (total effort: 92.4 person-hours) and conducted
leaf-litter-bag sampling at three streams in 2022. We observed a total of eight G. porphyriticus during surveys (two
adults and six larvae from three different sites) (CPUE: 0.06/h); two of the six larvae were captured in 84 leaf-litter-bag
checks (CPUE: 0.02/bag check). Both E. lucifuga and G. porphyriticus appear to be rare members of the salamander
community in northeastern Mississippi, as both are known from fewer than 10 localities in Mississippi and have low
encounter rates. Periodic surveys are needed to determine if future changes occur in the distribution or abundance of
either species. Future surveys, especially on private properties, could reveal additional localities for both species.