DOI: 10.5061/dryad.rbnzs7hjq
title: Physiological and morphological traits affect contemporary range expansion and implications for species distribution modeling in an amphibian species

description: Species range shifts due to climate alterations have been increasingly
 well-documented. Although amphibians are one of the most sensitive groups
 of animals to environmental perturbations due to climate change, almost no
 studies have offered evidence of poleward distribution shifts in this
 taxon in response to climate warming. Range shifts would be facilitated by
 variation in traits associated with the ability of species to persist
 and/or shift their range in the face of climate change, but the extent and
 consequences of intraspecific variation in these traits is unclear. We
 studied the role of intraspecific variation in the ongoing range shift of
 green treefrogs (Hyla cinerea) in response to climate change. We explored
 factors that are often associated with range shifts to test the hypothesis
 that there are differences in these traits between recently range-expanded
 and nearby historical populations. We then tested the consequences of
 intraspecific variation for modeling climate-induced range shifts by
 comparing species distribution models (SDM) that used as input either data
 from the entire species range or separate inputs from ‘subpopulations’
 corresponding to the historical range or the recently-expanded range. We
 expected that building a separate SDM for each population would more
 accurately characterize the species range if historical and expanded
 populations differed in traits related to their response to climate.
  We found that critical thermal minimum decreased and thermal
 breadth increased with latitude, but the effect of latitude was
 significantly stronger for expanded populations compared to historical
 populations. Additionally, we found that individuals from expanded
 populations had longer leg lengths when compared to their historical
 counterparts. Lastly, we found higher model accuracy for one of the
 population-level SDMs than the species-level SDM. Our results suggest that
 thermal tolerance and dispersal morphologies are associated with amphibian
 distributional shifts as these characteristics appear to facilitate rapid
 range expansion of a native anuran. Additionally, our modeling results
 emphasize that SDM accuracy could be improved by dividing a species range
 to consider potential differences in traits associated with climate
 responses. Future research should identify the mechanisms underlying
 intraspecific variation along climate gradients to continue improving SDM
 prediction of range shifts under climate change.
description: Green treefrogs<em> </em>(<em>Hyla
 cinerea</em>) were collected under permits obtained from the
 Kentucky Department of Fish and Wildlife Resources (educational wildlife
 collecting permit #SC2211235, issued to OME), Illinois Department of
 Natural Resources (permit #HSCP 19-48, issued to D. Edwards), and
 Tennessee Wildlife Resources Agency (permit #5510, issued to BZ).
 Permission to collect frogs on sites in Shawnee National Forrest was
 granted by Tim Pohlman, District Ranger of Shawnee National Forrest’s
 Hidden Springs/Mississippi Bluffs Ranger Districts.
description: # Physiological and morphological traits affect contemporary range
 expansion and implications for species distribution modeling in an
 amphibian species
 [https://doi.org/10.5061/dryad.rbnzs7hjq](https://doi.org/10.5061/dryad.rbnzs7hjq) Owen M. Edwards1,3, Lu Zhai2, Michael S. Reichert1, Ciaran A. Shaughnessy1, Logan Ozment2, Bo Zhang1* 1Department of Integrative Biology, Oklahoma State University, Stillwater, Oklahoma, USA 2Department of Natural Resource Ecology and Management, Oklahoma State University, Stillwater, Oklahoma, USA 3Oklahoma Biological Survey, University of Oklahoma, Norman, Oklahoma, USA *Corresponding author: Bo Zhang, 1Department of Integrative Biology, Oklahoma State University, Stillwater, OK, USA, 74078. Phone: 786-863-6669, Email: [bozhangophelia@gmail.com](mailto:bozhangophelia@gmail.com) ## Descriptions of the data sets associated with the analyses presented in the paper: ### JAE\_GTF\_Morph\_Data.xlsx This is the data file containing morphological data for frogs presented in the study. The following are explanations of the variables: * Species - Scientific name of collected individual  * Identification - Unique identification for each frog during the study  * Specimen Tag # - Personal Identification specimen Tag  * County - County in which the individual was collected * Colonization Stage - Population spatial history (expanded or historical) * SVL1 mm - First measurement of Snout-vent length (mm) * SVL2 mm - Second measurement of Snout-vent length (mm) * SVL3 mm - Third measurement of Snout-vent length (mm) * Average_SVL mm - The average of SVL1-3 (mm) * Left_Tibulafibula1 mm - First measurement of left tibulafibula (mm) * Left_Tibulafibula2 mm - Second measurement of left tibulafibula (mm) * Left_Tibulafibula3 mm - Third measurement of left tibulafibula (mm) * Average_LTF mm - The average of Left_Tibulafibula1-3 (mm) * Right_Tibulafibula1 mm - First measurement of right tibulafibula (mm) * Right_Tibulafibula2 mm - Second measurement of right tibulafibula (mm) * Right_Tibulafibula3 mm - Third measurement of right tibulafibula (mm) * Average_RTF mm - The average of Right_Tibulafibula1-3 (mm) * Average_Tibulafibula mm - The average of Average_LTF (mm) and Average_RTF (mm) * TF/SVL - Average_Tibulafibula (mm) divided by Average_SVL (mm) * Left_Femur1 mm -  First measurement of left femur (mm) * Left_Femur2 mm -  Second measurement of left femur (mm) * Left_Femur3 mm -  Third measurement of left femur (mm) * Average_LF mm - The average of Left_Femur1-3 (mm) * Right_Femur1 mm -  First measurement of right femur (mm) * Right_Femur2 mm -  Second measurement of right femur (mm) * Right_Femur3 mm -  Third measurement of right femur (mm) * Average_RF mm - The average of Right_Femur1-3 (mm) * Average_Femur mm - The average of Average_LF (mm) and Average_RF (mm) * F/SVL - Average_Femur (mm) divided by Average_SVL (mm) * Left_Humerus1 mm - First measurement of left humerus (mm) * Left_Humerus2 mm - Second measurement of left humerus (mm) * Left_Humerus3 mm - Third measurement of left humerus (mm) * Average_LH mm - The average of Left_Humerus1-3 (mm) * Right_Humerus1 mm - First measurement of right humerus (mm) * Right_Humerus2 mm - Second measurement of right humerus (mm) * Right_Humerus3 mm - Third measurement of right humerus (mm) * Average_RH mm - The average of Right_Humerus1-3 (mm) * Average_Humerus mm - The average of Average_LH (mm) and Average_RH (mm) * H/SVL - Average_Humerus (mm) divided by Average_SVL (mm) * Left_Radioulna1 mm - First measurement of left radioulna (mm) * Left_Radioulna2 mm - Second measurement of left radioulna (mm) * Left_Radioulna3 mm - Third measurement of left radioulna (mm) * Average_LR mm - The average of Left_Radioulna1-3 (mm) * Right_Radioulna1 mm - First measurement of right radioulna (mm) * Right_Radioulna2 mm - Second measurement of right radioulna (mm) * Right_Radioulna3 mm - Third measurement of right radioulna (mm) * Average_RR mm - The average of Right_Radioulna1-3 (mm) * Average_Radioulna mm - The average of Average_LR (mm) and Average_RR (mm) * RU/SVL - Average_RR (mm) divided by Average_SVL (mm) * Skullwidth1 mm - First measurement of skull width (mm) * Skullwidth2 mm - Second measurement of skull width (mm) * Skullwidth3 mm - Third measurement of skull width (mm) * Average_SW mm - The average of Skullwidth1-3 (mm) * SW/SVL - Average_SW (mm) divided by Average_SVL (mm) ### JAE\_GTF\_Thermal\_Data.xlsx This is the data file containing thermal tolerance data for frogs presented in the study. The following are explanations of the variables: * Species - Scientific name of collected individual  * Identification - Unique identification for each frog during the study  * Specimen Tag - Personal Identification specimen Tag  * Colonization Stage - Population spatial history (expanded or historical) * Sex - Sex of individual (male or female) * State - Two letter state abbreviation from where the individual was collected  * CollectionLocality - Common name for location from which individual was collected * Population - County in which the individual was collected * Date of Collection - Date at which individual was collected (month/day/year) * Latitude - Latitude coordinates * Longitude - Longitude coordinates * Collector - name(s) of collectors  * Mass (g) - weight (g) * Tb (body temperature)°C - individual body temperature (°C) * Ctmin °C - critical thermal minimum (°C) * Ctmax °C - critical thermal maximum (°C) * warmingtolerance °C - Ctmax °C minus Tb (body temperature)°C  * Breadth °C - Ctmax °C minus Ctmin °C