Written by guest author Gavin Graham, summer 2025 NW CASC science communications intern
Is there a shortcut to saving species that are affected by our changing climate? For one group of Northwest Climate Adaptation Science Center-supported researchers, what started as an attempt to understand how the changing climate affects a group of threatened amphibians in the Northwest, led them to unexpected findings and insights about species management in a changing climate. These findings reveal possible pitfalls in a climate adaptation strategy that has recently been gaining traction.
A fresh NW CASC-supported study led by Washington State University researchers Sky Button and Jonah Piovia-Scott, in collaboration with the U.S. Forest Service, set forth to model how the changing climate is affecting amphibians at risk in the Pacific Northwest. Their findings, published in the journal Ecological Indicators, suggest that utilizing one species to make conservation decisions about other, similar species can be misleading for certain groups, even though the species may look the same on paper.
When there are not enough resources or time to study each species in depth, wildlife managers sometimes rely on an “indicator species” approach — studying how climate change impacts one species and generalizing those findings to a broader group of similar species, allowing for more efficient, climate-smart planning.
Amphibians are the most threatened vertebrate class in the world. They face pressure from the effects of climate change and human interference, including habitat loss, invasive species, diseases and climate warming. The Pacific Northwest is home to more than 30 species of frogs and salamanders, making it a hotspot of amphibian diversity. Since many of these amphibians are being threatened by the impacts of a changing climate as well as other threats like invasive species and disease, researchers and wildlife managers in the Northwest are collaborating to find efficient climate adaptation strategies that can support vulnerable amphibians. When there are not enough resources or time to study each species in depth, wildlife managers sometimes rely on an “indicator species” approach — studying how climate change impacts one species and generalizing those findings to a broader group of similar species, allowing for more efficient, climate-smart planning. As Jonah describes, “It makes sense in the presence of limited resources. We’re going to use information about one species to represent another.” But the new study suggests shortcuts like this may not always work.
Jonah and his team of researchers aimed to assess the impact of climate change on amphibians of high conservation concern in the Pacific Northwest. The first step was identifying which species had enough data to support the creation of species distribution models (SDMs) — used to analyze environmental variables that are associated with suitable habitat for a species and predict what kinds of habitats will be suitable under a warmer climate. The research team selected four groundwater-dependent amphibian species, all of which are listed as Species of Greatest Conservation Need in at least one state: Rocky Mountain tailed frog, Cope’s giant salamander, Coeur d’Alene salamander, and Van Dyke’s salamander. Considered habitat specialists, these four species can only tolerate a narrow range of environmental conditions. Unfortunately, their habitats are expected to be highly impacted by changing snowmelt and precipitation under climate change. These similarities led the research team to think that these species would be impacted similarly under climate warming — that their suitable habitat would shrink under warmer conditions. Though the team initially chose the species based on their data availability, they realized that because of their similarities, the study could be a good opportunity to test the indicator species approach.
“We didn’t go into this particular project with the notion that it was about an indicator species… But we had this sort of striking result… These species seem very similar, but actually… they are not at all aligned in terms of the projected impacts of climate change.”
The team developed species distribution models using variables including groundwater availability, temperature, precipitation, and geology, to create maps showing current habitat suitable for their four study species. Then, using climate change projections from global climate models, they generated maps showing projected habitat suitability for these species under climate change. Surprisingly, they found that the future trajectories of these species are different despite many ecological similarities. Says Jonah, “We didn’t go into this particular project with the notion that it was about an indicator species… But we had this sort of striking result… These species seem very similar, but actually… they are not at all aligned in terms of the projected impacts of climate change.”
They found that the Rocky Mountain tailed frog and Cope’s giant salamander experienced modest shifts in the amount of suitable habitat. On the other hand, the Coeur d’Alene salamander displayed a major expansion of suitable habitat under a warmer climate. Surprisingly, the closely related Van Dyke salamander, its sister species, revealed a major contraction in suitable habitat, specifically in the Washington Cascades Range.
These findings show that using one species to infer the future of others, even within similar ecological groups, may result in generalizations leading to misguided conservation efforts.
So how will this research be applied in the world? This research was designed and completed with input from the people who need it most: state and federal wildlife managers. Managers at these agencies are in charge of protecting these species, and they need accurate and current information on how to incorporate climate considerations into their conservation planning for each species. As Jonah explains, “their input is critical because they tell us what they need to know, and we try to design our research to help meet their informational needs.” Studies like these can help them identify how much of a threat climate change is to different species, and when to use, or not use, strategies like the indicator species approach. In addition, this can help organizations prioritize funding and their conservation actions, like species relocation and habitat protection, based on which amphibians are most vulnerable.
More broadly, these findings challenge the efficacy of the climate indicator approach for habitat specialists. For many habitat specialists, species-specific approaches will be needed, which will require better ecological data to understand how these often-understudied species are impacted by climate change.
As far as what’s next for Jonah, this research has sparked many new questions and ideas for future research. Jonah is interested in revising the research, expanding the modeling to include more species and more habitats. When asked about future studies, Jonah stated, “There are other threats that are critical, that would be really hard to capture using this kind of approach… a great example is disease, which is a big threat to a number of other amphibian species… We’re working on that now.” Jonah brings up an important point that incorporating other stressors, like disease, into future research can provide a more comprehensive understanding of how species cope under multiple threats. In this changing world and climate, researchers like Jonah are paving the way for more precise, climate-smart conservation strategies.
This story was written by Gavin Graham, NW CASC’s summer 2025 science communications intern. Gavin is currently an undergraduate at the University of Washington, majoring in environmental studies and minoring in business administration. Gavin can be reached at gaving4@uw.edu.