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

Abstract

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.”

Projected northward shifts in eastern red‐backed salamanders due to changing climate

“…Dispersal‐limited species are likely to be more strongly impacted by these shifts because they cannot quickly respond to rapid environmental change. Given the wide geographical range of P. cinereus and the numerous investigations into its life history and behavior (reviewed in Fisher‐Reid et al, 2021 ), as well as the importance of salamanders generally as environmental indicators (Buckley & Jetz, 2007 ; Feder & Burggren, 1992 ; Fleming et al, 2020 ; Welsh & Droege, 2001 ), this species is an excellent model system for utilizing species distribution models/ecological niche models to better understand the macroclimatic factors driving past, present, and future potential range shifts in dispersal‐limited amphibians.…”

“…Species distribution models/ecological niche models provide a foundation for where we should expect to lose P. cinereus populations using macroclimatic variables. To better understand the effects of microclimatic changes on P. cinereus and other salamanders accompanying climate change, as well as determine whether the decreases in favorability predicted by our models are fulfilled, more long‐term field studies are necessary (Fisher‐Reid et al, 2021 ), especially at the extremes of the distribution range. Combining species distribution models using macroclimatic variables with field data from local, finer‐scale variables (Enriquez‐Urzelai, Kearney, et al, 2019 ) will help to elucidate future trends for P. cinereus , for North American salamanders, and for dispersal‐limited taxa more generally.…”

“…This previous work has established the microclimatic preferences of P. cinereus , such as how air and soil temperature and precipitation impact detection rates of P. cinereus (Hernández‐Pacheco et al, 2019 ), and how temperature impacts the species' growth rates and the onset of sexual maturity (Muñoz, Miller Hesed, et al, 2016 ). As a result of this wealth of research, P. cinereus has become a model species for understanding the impacts of microclimate on amphibian ecology, behavior, and dispersal (reviewed in Fisher‐Reid et al, 2021 ). However, the effects of macroclimate on P. cinereus have been less fully explored, and the potential impacts of future climate on the species as a whole have yet to be studied via species distribution modeling, which may provide important insights into potential distributional changes over the next century (e.g., Zhang et al, 2020 in Chinese giant salamanders).…”

“…These data will generate new insights into large‐scale climatic impacts on P. cinereus and build on our current understanding of P. cinereus ecology. As P. cinereus is becoming a model system in amphibian ecology (Fisher‐Reid et al, 2021 ), these data will be potentially helpful in better understanding range shift ecology in amphibians generally, especially lungless amphibians, in the face of rapidly accelerating climate change.…”