Is the future already here? The impact of climate change on the distribution of the eastern coral snake (Micrurus fulvius).

Jennifer N Archis,Christopher Akcali,Bryan L Stuart,David Kikuchi,Amanda J Chunco

doi:10.7717/peerj.4647

Abstract

Anthropogenic climate change is a significant global driver of species distribution change. Although many species have undergone range expansion at their poleward limits, data on several taxonomic groups are still lacking. A common method for studying range shifts is using species distribution models to evaluate current, and predict future, distributions. Notably, many sources of ‘current’ climate data used in species distribution modeling use the years 1950–2000 to calculate climatic averages. However, this does not account for recent (post 2000) climate change. This study examines the influence of climate change on the eastern coral snake (Micrurus fulvius). Specifically, we: (1) identified the current range and suitable environment of M. fulvius in the Southeastern United States, (2) investigated the potential impacts of climate change on the distribution of M. fulvius, and (3) evaluated the utility of future models in predicting recent (2001–2015) records. We used the species distribution modeling program Maxent and compared both current (1950–2000) and future (2050) climate conditions. Future climate models showed a shift in the distribution of suitable habitat across a significant portion of the range; however, results also suggest that much of the Southeastern United States will be outside the range of current conditions, suggesting that there may be no-analog environments in the future. Most strikingly, future models were more effective than the current models at predicting recent records, suggesting that range shifts may already be occurring. These results have implications for both M. fulvius and its Batesian mimics. More broadly, we recommend future Maxent studies consider using future climate data along with current data to better estimate the current distribution.

Highlights

Climate change is dramatically altering the distribution of species across the globe (Parmesan, 2006; Chen et al, 2011)
Area under the curve (AUC) values supplied by Maxent may differ from true AUC values because Maxent relies on background data and not true absence data, as noted in Proosdij et al (2016)
Current Maxent models suggest coral snake distributions are restricted to the southeastern United States, with only very limited areas of high habitat suitability; the majority of high to moderate habitat suitability areas are restricted to Florida

Summary

Introduction

Climate change is dramatically altering the distribution of species across the globe (Parmesan, 2006; Chen et al, 2011). Climate change has been hypothesized to drive range shifts at poleward range limits, especially for warm-adapted species (Parmesan, 2006). The impact of climate change on the distribution of the eastern coral snake (Micrurus fulvius). Hughes (2000) notes that a change of 3 degrees Celsius can result in poleward isotherm shifts of 300–400 km in temperate zones; the ranges of species are expected to expand in response. In a review of range shifts in 434 species of varied taxa including birds, butterflies, and alpine herbs, 80% had moved in the direction predicted by climate change (Parmesan & Yohe, 2003). The cascading effects of range shifts are manifold and include: decoupling of intricate predator–prey interactions and multitrophic effects (Gilman et al, 2010), increased invasion (Hellmann et al, 2008) and infection (Pounds et al, 2006), increased intraspecific competition (Huey et al, 2009), and potential competitive exclusion in extreme cases (Gilman et al, 2010; Tylianakis et al, 2008; Chapin III et al, 2000)

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Results

Conclusion