An analysis of habitat utilization and feeding ecology of Plethodon richmondi and Plethodon cinereus in northern West Virginia

Studies were conducted on the comparative microhabitat requirements and feeling habits of the ravine salamander, Plethodon richmondi and the redback salamander, P. cinereus in northern West Virginia. Plethodon richmondi had a mean SVL of 49.7 ± 7.1 mm and were significantly larger than P. cinereus which had a mean SVL of 37.2 ± 8.0 mm. Both species had biennial egg laying patterns and deposited eggs in late spring or early summer. Juvenile P. richmondi were not surface active except for the early spring and neonates did not become surface active until the ensuing spring; conversely, P. cinereus juveniles exhibited more activity throughout the entire active season and neonates became surface active during the fall of the year they hatched. Neither species were surface active during the warmest and driest months of summer and early fall (June - October). Of the 22 environmental parameters measured, eight were significantly different between the two species. Plethodon richmondi utilized rocks with a significantly larger circumference, diameter length, mean diameter and impression diameter length; in addition, P. richmondi used rocks that exhibited more contact between the bottom of the rock and the surface of the ground. Plethodon richmondi also utilized soil with a lower pH and temperature as well as soil with a higher soil moisture content. Plethodon cinereus displayed more variability in measured environmental parameters and had a larger variance for 17 of the 22 environmental parameters. Principal components analysis revealed that P. cinereus utilized a broader range of habitats than P. richmondi. There was a significant correlation in the diets of P. richmondi and P. cinereus (r.s = 0.813); in addition, all diets compared were significantly correlated and resource overlap calculations were high for all comparisons except between P. richmondi at North Bend and Long Run (0.45). Plethodon richmondi had a significantly smaller volume of food on days when rainfall for the previous three days was \u3c 0.42 inches than for dates when rainfall for the previous three days was \u3e 0.42 inches but there was not a significant difference for P. cinereus. The sum of the environmental and feeding data show that P. richmondi had a more narrow set of environmental requirements and may be affected more by extreme values which may explain at least partly the differences in macrodistributional patterns