Aquatic Habitats and Communities
Science Center Objects
The Pacific Northwest includes a patchwork of public lands managed by numerous state and federal agencies. Our research informs and supports these agencies as they conserve and manage native amphibian species, including pre- and post-treatment assessment, decision support, long-term monitoring, population translocation, and habitat restoration.
Many of the systems we work in have altered hydrological regimes, so a focus of our research is understanding native species relationships with timing and amount of water. Examples are studies of amphibian distribution and abundance relative to different water management scenarios and relationships with active beaver dams.
USGS researchers Brome McCreary (orange vest) and Chris Pearl take measurements on Cascades frog at a mountain lake in Oregon.
(Credit: Stephanie Galvan, USGS. Public domain.)
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Date published: September 20, 2017Status: ActiveHerpetological Research Team (FRESC)
The Herpetological Research Team focuses on issues related to conservation and management of amphibians and other aquatic and semi-aquatic species. Among our current studies are effects of invasive species, disease, and land use change on the dynamics of amphibian communities to inform conservation and management decision making.
Contacts: Michael J Adams, Christopher A Pearl
A new parameterization for integrated population models to document amphibian reintroductions
Managers are increasingly implementing reintroduction programs as part of a global effort to alleviate amphibian declines. Given uncertainty in factors affecting populations and a need to make recurring decisions to achieve objectives, adaptive management is a useful component of these efforts. A major impediment to the estimation of demographic...
Duarte, Adam; Pearl, Christopher; Adams, M.J.; Peterson, James
Herpetological monitoring and assessment on the Trinity River, Trinity County, California—Final report
The primary goal of the Trinity River Restoration Program is to rehabilitate the fisheries on the dam-controlled Trinity River. However, maintaining and enhancing other wildlife populations through the restoration initiative is also a key objective. Foothill yellow-legged frogs (Rana boylii) and western pond turtles (Actinemys marmorata) have been...
Snover, Melissa L.; Adams, M.J. Evidence of counter-gradient growth in western pond turtles (Actinemys marmorata) across thermal gradients
Counter-gradient growth, where growth per unit temperature increases as temperature decreases, can reduce the variation in ectothermic growth rates across environmental gradients. Understanding how ectothermic species respond to changing temperatures is essential to their conservation and management due to human-altered habitats and changing...
Snover, Melissa; Adams, M.J.; Ashton, Donald T.; Bettaso, Jamie B.; Welsh, Hartwell H. Using occupancy models to accommodate uncertainty in the interpretation of aerial photograph data: status of beaver in Central Oregon, USA
Beavers (Castor canadensis) influence habitat for many species and pose challenges in developed landscapes. They are increasingly viewed as a cost-efficient means of riparian habitat restoration and water storage. Still, information on their status is rare, particularly in western North America. We used aerial photography to evaluate changes in...
Pearl, Christopher A.; Adams, M.J.; Haggerty, Patricia K.; Urban, Leslie Short-term response of Dicamptodon tenebrosus larvae to timber management in southwestern Oregon
In the Pacific Northwest, previous studies have found a negative effect of timber management on the abundance of stream amphibians, but results have been variable and region specific. These studies have generally used survey methods that did not account for differences in capture probability and focused on stands that were harvested under older...
Leuthold, Niels; Adams, M.J.; Hayes, John P. Using spatiotemporal models and distance sampling to map the space use and abundance of newly metamorphosed Western Toads (Anaxyrus boreas)
High variability in abundance, cryptic coloration, and small body size of newly metamorphosed anurans have limited demographic studies of this life-history stage. We used line-transect distance sampling and Bayesian methods to estimate the abundance and spatial distribution of newly metamorphosed Western Toads (Anaxyrus boreas) in terrestrial...
Chelgren, Nathan D.; Samora, Barbara; Adams, M.J.; McCreary, Brome Demography and movement in a relocated population of Oregon Spotted Frogs (Rana pretiosa): Influence of season and gender
We used five years of recapture data and Bayesian estimation to assess seasonal survival, movement, and growth of Oregon Spotted Frogs (Rana pretiosa) relocated into created ponds at Dilman Meadow in Oregon, USA. We evaluate hypotheses specific to the relocation and elucidate aspects of R. pretiosa life history that are poorly known. The odds of...
Chelgren, N.D.; Pearl, C.A.; Adams, M.J.; Bowerman, J. Amphibian occurrence and aquatic invaders in a changing landscape: Implications for wetland mitigation in the Willamette Valley, Oregon
Despite concern about the conservation status of amphibians in western North America, few field studies have documented occurrence patterns of amphibians relative to potential stressors. We surveyed wetland fauna in Oregon's Willamette Valley and used an information theoretic approach (AIC) to rank the associations between native amphibian...
Pearl, Christopher A.; Adams, M.J.; Leuthold, N.; Bury, R. Bruce
Wetland management for amphibians in the Willamette Valley
Introduction In the past two decades, scientists around the world have increasingly noted losses of amphibian populations. Many of these declines have occurred in protected areas like national parks, where the causes mostly remain mysterious. However, in multipleuse landscapes, resource managers frequently face more obvious conservation...
Adams, M.J.; Pearl, Christopher A.; Bury, R. Bruce The endemic headwater stream amphibians of the American Northwest: Associations with environmental gradients in a large forested preserve
We used a large forested preserve (Olympic National Park, USA) to examine the habitat associations of a unique and environmentally sensitive stream amphibian fauna: Ascaphus truei Stegneger, Rhyacotriton olympicus (Gaige) and Dicamptodon copei Nussbaum. We quantified the relative abundance of stream amphibians and compared them to physical,...
Adams, M.J.; Bury, R. Bruce Pond permanence and the effects of exotic vertebrates on anurans
In many permanent ponds throughout western North America, the introduction of a variety of exotic fish and bullfrogs (Rana catesbeiana) correlates with declines in native amphibians. Direct effects of exotics are suspected to be responsible for the rarity of some native amphibians and are one hypothesis to explain the prevalence of amphibian...
Adams, M.J.