The relationship between climate and adult body size in redback salamanders (Plethodon cinereus)

Abstract

Several biogeographic studies of salamanders have described relationships between salamander body size and climate. We specifically selected Plethodon cinereus as a widely distributed species that was well represented in museum collections to investigate the effects of warming climate on adult body size. We found a positive correlation between mean maximum July temperature and body size, and a negative correlation between precipitation of the driest month and body size. Surface-collected adult P. cinereus were 2.3% larger in warmer counties on the coastal plain compared with cooler counties in the Appalachian Mountains. We compared salamanders collected between 1950 and 1970 versus those collected between 1980 and 2000 and found that body size increased 1.8% in counties on the coastal plain where mean maximum July temperatures had also increased by 0.5-1.2°C. Warming temperatures alone, however, did not adequately account for the observed size increases, because body size also increased 1.3% in places that experienced less than 0.25°C warming, but that difference was not statistically significant.

Seasonal differences in climate change explain a lack of multi-decadal shifts in population characteristics of a pond breeding salamander

“…Similar patterns were observed for how inter-annual variation in climate influence body size, despite the absence of an overall body size shift during the study period (Fig 2E and 2F). Although recent evidence suggests that climate change can lead to body size reductions in amphibians [7, 9], others have offered alternative explanations [56] or have found increases in body size [10, 57]. We did observe a positive relationship between body size and summer temperatures, which is contrary to our predictions and those of other studies.…”

Demographic consequences of changing body size in a terrestrial salamander

“…Along with other plethodontids, this species has a high sensitivity to temperature warming (Moore et al., 2018; Riddell et al., 2018), and has been hypothesized to undergo phenotypic changes under climate change. These changes include some natural populations decreasing in size (Caruso et al, 2014), while others increasing in size (McCarthy et al., 2017). Our study suggests that these shifts could lead to significant changes in the viability of our study population, a response potentially expected for other terrestrial ectotherm populations.…”

“…Several recent studies have focused on the quantification of body size changes and the potential for adaptive shifts in salamander size in response to climate change (Caruso et al, 2014; McCarthy et al., 2017; Riddell et al., 2018). Contradictory findings on the direction of the change in body size among P. cinereus populations have been reported (Li et al., 2013).…”

“…We estimated the elasticity of the population growth rate, the distribution of size, and the associated uncertainty to variation in survival and body size. This is important as several recent studies have reported P. cinereus body size changes and its potential for adaptive shifts in response to warming environments (Caruso et al, 2014; McCarthy et al., 2017; Riddell et al., 2018). Some populations have been found shrinking in size by up to 1.7% every decade (Caruso et al, 2014), while other populations are responding by increasing in size (McCarthy et al., 2017).…”

Towards an Integrative, Eco-Evolutionary Understanding of Ecological Novelty: Studying and Communicating Interlinked Effects of Global Change

“…Complementary to the site-specific perspective, the organism-centered perspective considers whether and how organisms are affected by abiotic or biotic human-induced change, for example, in their morphological traits, behavior, or fitness (Sih et al 2011, McCarthy et al 2017). The basic idea is that abiotic and biotic environmental conditions will be perceived as novel by a focal organism if they are outside the range of environmental conditions experienced during a species’ evolutionary history (see e.g., Wilsey et al 2011, Saul et al 2013).…”