Year of Award
2024
Document Type
Dissertation
Degree Type
Doctor of Philosophy (PhD)
Degree Name
Fish and Wildlife Biology
Department or School/College
Wildlife Biology Program
Committee Co-chair
Lisa A. Eby, Blake R. Hossack
Commitee Members
Zachary A. Cheviron, Winsor H. Lowe, Paul M. Lukacs
Abstract
Amphibians have experienced major declines and are highly vulnerable to the impacts of climate change. Yet we still lack sufficient information to understand where amphibians are most vulnerable to changes in climate and how effects might manifest. In this dissertation, I worked to understand risks due to climate change and investigate effective indicators of survival in amphibians. To predict which species might be most affected by increasingly dry conditions, in Chapter 1, I extended the climate change vulnerability assessment framework to rank amphibian vulnerability based on projected climate change and species life history traits. Traits including clutch size, daily activity period, and range size within the study area indicated either decreased sensitivity or increased capacity to adapt to change. Using projections of high variance in water deficit, environmental changes overwhelmed traits in vulnerability rankings. For projections with low variance in future water deficit, life history traits discriminated among differences in species climate vulnerability. In Chapter 2, I assessed which measures of body condition were most useful in describing body fat and lean mass and if condition indices predicted growth. Scaled mass index and residual index were related to fat and lean mass, and were uncorrelated with body length. Body condition predicted summer growth in Columbia spotted frogs at my focal study site. To investigate the role of future drier conditions amongst multiple stressors on amphibian populations, in Chapter 3, I explored patterns in the effects of increased drying on survival across 29 amphibian populations in the western United States, and whether increased body condition might help buffer negative effects on survival. I found that at higher elevation sites, survival tended to increase with drought. Increased body condition reduced the likelihood that drier conditions would result in decreased survival. This dissertation improves our understanding of climate risks to amphibian populations and how to better predict those risks, with the objective of improving goal-setting measures to minimize biodiversity loss.
Recommended Citation
Hinderer, Ross Kenneth, "INTEGRATING INDIVIDUAL AND SPECIES TRAITS TO BETTER IDENTIFY RISKS TO PERSISTENCE AND SURVIVAL IN AMPHIBIAN POPULATIONS" (2024). Graduate Student Theses, Dissertations, & Professional Papers. 12387.
https://scholarworks.umt.edu/etd/12387
© Copyright 2024 Ross Kenneth Hinderer