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Grantee Research Project Results

NCER Grantee Research Project Results

Predicting the Biotic Effects of Climate Change: An Integrative Approach Using an Ectothermic Vertebrate Model

EPA Grant Number: FP917231
Title: Predicting the Biotic Effects of Climate Change: An Integrative Approach Using an Ectothermic Vertebrate Model
Investigators: Telemeco, Rory S.
Institution: Iowa State University
EPA Project Officer: Jones, Brandon
Project Period: August 23, 2010 through August 22, 2013
Project Amount: $111,000
RFA: STAR Graduate Fellowships (2010)
Research Category: Academic Fellowships , Fellowship - Global Change

Description:

Objective:

Because numerous aspects of reptilian biology, from embryonic development to behavior, are strongly impacted by the thermal environment, reptiles are thought to be at high risk of climate change-induced decline. Even so, virtually nothing is known about the effects of thermal variation, much less climate change, on the natural history and development of many reptile species. This research project will help bridge these knowledge gaps using alligator lizards (genus Elgaria, family Anguidae) as a model system.

Synopsis:

Numerous aspects of reptile biology are impacted by temperature. Because of this, reptiles are at high risk of climate change-induced decline. However, little is known about the specific effects of thermal variation, much less climate change, on many reptile species. This project will help bridge these knowledge gaps by combining field and laboratory experimental techniques with molecular techniques and bioclimatic modeling using alligator lizards (genus Elgaria) as a model system.

Approach:

To determine the probable effects of climate change on alligator lizards and their relatives, this research will combine field and laboratory experimental techniques with cutting-edge molecular phylogeographic techniques and bioclimatic modeling. The first stage of research will involve experimental incubation studies designed to describe the effects of thermal variation during embryonic development on offspring phenotype and fitness. Next, field and laboratory experiments will be utilized to examine whether or not female lizards can effectively buffer their progeny from climatic variation by altering the microclimate of their nests (nest depth, shade cover, moisture, etc). This information will then be used to build bioclimatic envelope models capable of predicting the likely effects of climate change on alligator lizards and their relatives. For this model to be effectively applied, it will be important to identify taxonomic groups of conservation concern, particularly cryptic species that may not be immediately obvious. Therefore, molecular phylogeographic techniques will be utilized to identify any cryptic species within the southern alligator lizard (Elgaria multicarinata) species group. Finally, the bioclimatic envelope model will be applied to threatened alligator lizard species and any identified cryptic species such that management recommendations may be made.

Expected Results:

Results from the experimental portions of this study will detail the effects of varied thermal conditions on the reproductive life-histories of alligator lizards and the capacity of alligator lizards to adaptively and/or plastically adjust their phenotypes in response to climate change. For example, this research will determine whether or not increasing temperatures in the nest will skew the sex ratios of offspring, what temperatures are too high for successful embryogenesis, the effects of climatic variation on natural nests in the field, and the ability of females to adjust their behavior or physiology to counter these deleterious effects. The molecular portion of the study will result in the reconstruction of a phylogeny for Elgaria multicarinata that will resolve the validity of each E. multicarinata subspecies. There are three possible fates for the currently recognized subspecies: 1) they might be supported; 2) they might not be supported, in which case it will be recommended that the subspecies designation be removed; or 3) they might be strongly supported as individual clades, in which case it will be recommended that they be elevated to species status and considered as discrete taxonomic units for conservation purposes. Finally, the modeling portion of the study will incorporate the experimental and molecular data from the previous portions, and current climate change predictions, into a model that predicts the effects of future climate change on high-risk groups of alligator lizards. With this model, it will be possible to make informed management recommendations for these and other lizards.

Potential to Further Environmental/Human Health Protection:

This study will provide information vital to the effective management of alligator lizards and their relatives as global climates change. Furthermore, with minor modification the bioclimatic envelope model that results from this study should be applicable to other, diverse reptile species (particularly squamates, snakes, and lizards), thereby allowing predictions to be made about how these populations will likely respond to impending climate change.

Supplemental Keywords:

alligator lizard, Elgaria, Anguidae, squamate, climate change, global warming, life history, temperature-dependent sex determination, bioclimatic envelope,

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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.

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