Repeatability of water loss and gain rates of Plethodon cinereus

Water loss and gain rates of amphibians are important to understanding their ecology, especially for plethodontid salamanders. We report the first estimates of repeatability of relative water loss and gain rates of the two major colour morphs of the Eastern Red-backed Salamander, Plethodon cinereus, in the fall and spring seasons. Repeatability of relative water loss in P. cinereus was >0 in the fall but not in the spring. Repeatability of relative water gain was significant for all salamanders pooled in the fall, and was not repeatable in the spring. There were no apparent differences in repeatability of relative water loss or gain between the two colour morphs. Our results suggest that the repeatability of relative water loss and gain rates varies by season, but not by colour morph.

Eastern red-backed salamanders: A comprehensive review of an undervalued model in evolution, ecology, & behavior

What makes a model organism? Identifying the qualities of a model organism has been given a great deal of attention in the biomolecular sciences, but less so in the fields of evolution, ecology, and behavior (EEB). In EEB, biotic and abiotic variation are features to understand, not bugs to get rid of, and EEB scientists often select organisms to study which best suit the scientific question at hand. Successful EEB model organisms can be studied at multiple biological scales and have a wealth of accumulated knowledge on which current research programs build. A recent call within EEB to invest in the inclusive development of diverse model systems and scientists has led us to evaluate the standing of the widespread, abundant, terrestrial salamander we study, the eastern red-backed salamander (Plethodon cinereus). We first look at salamanders as EEB models more generally, to determine where P. cinereus fits in this broader context. We next present a comprehensive review of the literature on the eastern red-backed salamander (Plethodon cinereus) since the last comprehensive review was completed in 1998. The core of our paper reviews 410 recent studies and highlights inconsistencies, gaps in our knowledge, and future directions in the context of the 1998 review. Finally, we present a collaborative research network, SPARCnet, as a nascent infrastructure for continued research on P. cinereus. Here, we especially discuss how this type of infrastructure can be broadly applied not just to other salamanders, but to other model systems, so that the future of EEB research may benefit from models which accurately represent, in Darwin’s words, “endless forms most beautiful and most wonderful.”

Woodland salamander population structure and body condition under irregular shelterwood systems

Ecosystem-based management aims to preserve old-growth forest attributes using techniques mimicking natural disturbances. One such technique is irregular shelterwood logging, but its impacts on forest floor organisms are poorly known. Our objective was to quantify the effects of three different treatments of irregular shelterwood on population structure and the body condition of the eastern red-backed salamander (<i>Plethodon cinereus</i>) 5–6 years following harvesting. A total of 64 sites in western Québec were sampled using artificial refugia and quadrat searches. Large salamanders (> 32 mm) were more abundant in the gap treatment than in strip, uniform, or control treatments. Small salamanders (≤ 32 mm) followed the same pattern, although the differences were marginal. For a given treatment, small salamanders were as abundant as large salamanders. Salamander body condition differed between the two years of sampling, but did not differ among treatments, regardless of salamander size. We conclude that environmental conditions in irregular shelterwood treatments 5–6 years following harvesting support populations of small vertebrates on the forest floor.

Range limitation of the Peaks of Otter salamander (Plethodon hubrichti) due to competition with the eastern red-backed salamander (Plethodon cinereus) in sympatry

The Peaks of Otter salamander, Plethodon hubrichti, is a montane species found at altitudes above 442 m within a 117 km2 area of the Blue Ridge Mountains in central Virginia, USA. In areas where this species is sympatric with the eastern red-backed salamander (Plethodon cinereus) it seemed likely that P. hubrichti populations were either depressed or eliminated. The habitability of areas beyond the current range boundaries for P. hubrichti is supported by several disjunct populations in areas sympatric with P. cinereus. From 2009 to 2012 we tested whether P. hubrichti was negatively impacted by competition with P. cinereus by removing P. cinereus from treatment plots at three sympatric field locations. The number of surface-active (SA) P. hubrichti increased significantly more on treatment plots than on corresponding reference plots, whereas the number of SA P. cinereus decreased significantly more on treatment plots than on reference plots. The removal of every one P. cinereus from the treatment plots led to an increase of 0.69 P. hubrichti. These results emphasise the importance of conserving mature hardwood forests along the perimeter of the P. hubrichti distribution, where it is sympatric with P. cinereus, so as to prevent future range contraction of this vulnerable species.