Monitoring Amphibians at Mount Rainier National Park, 2018 Summary

A brown toad
Figure 1. Western Toad (Anaxyrus boreas) juvenile.

Introduction

Mount Rainier National Park encompasses 236,381 acres of land in Washington State and includes a wide range of ecosystems. There are approximately 385 lakes and more than 400 streams in the park, and these aquatic ecosystems provide crucial habitats to many amphibian species. Most amphibians spend a portion of their lives in aquatic habitats, and they can be greatly impacted by changing environmental conditions. Therefore, monitoring amphibian species abundance can indicate water quality and overall ecosystem health.

Fourteen species of amphibians are known to occur in the park including nine species of salamanders and five species of frogs/toads. One species of particular interest is the western toad (Anaxyrus boreas), currently considered a candidate species for listing by Washington State. The Southern Rocky Mountain population known as the boreal toad (Anaxyrus boreas boreas) is under review for listing under the federal Endangered Species Act. At Mount Rainier National Park the western toad is considered one of the least common amphibians in the park.

What are we doing?

We are monitoring amphibian abundance throughout Mount Rainier National Park, concentrating our efforts at sites where western toads are known to occur. We monitor the phenology of western toad larva and document changes in ephemeral breeding habitats. Our project volunteers have also monitored amphibian mortality at select lakes, conducted night surveys, and surveyed for larval dragonflies.

A girl holds a frog up in her clasped hands.
Figure 2. A young volunteer holds an adult Cascade frog during a Visual Encounter Survey.

Monitoring Objectives

  1. Engage volunteers in park science through active participation in field data collection.
  2. Monitor amphibian populations at western toad breeding sites throughout the park.
  3. Provide data to the National Park Service on the status of aquatic environments and dependent species within Mount Rainier National Park.
A series of images show development of a western toad from egg to tadpoles to larva metamorphosis to juvenile toad.
Figure 3. Western Toad A) egg string, B) tadpoles, C) larva undergoing metamorphosis, and D) recently metamorphosed juvenile found during the 2016 season.

Monitoring Methods

  • Surveys occur from early July to early September.
  • We are using a survey method called a Visual Encounter Survey (VES) to monitor amphibian species abundance.
  • At Western Toad breeding sites we document specific life stage and size of larval toads (tadpoles), making repeat visits to some sites over the course of the season.
A man wades through the edge of a mountain lake.
Figure 4. A volunteer monitors salamanders at Upper Crystal Lake.

Results: Volunteer Involvement

Since the establishment of this citizen science program in 2009, over 250 volunteers have participated in the project. Volunteers represent a wide range of ages, backgrounds, and experience levels with both data collection and the outdoors. While day-hiking and backpacking on extended trips, volunteers have observed thousands of amphibians, as well as monitored larval toad development at several sites. Volunteers have also contributed to our knowledge of mercury in the park’s lakes and wetlands by collecting dragonfly larvae samples for the nationwide Dragonfly Mercury Project. As of 2018, volunteers have contributed over 5000 hours to amphibian surveys.

A woman in waders stands hip deep in a subalpine pond surrounded by mountains.
Figure 5. Citizen Science Coordinator measuring lake depth at Mirror Lakes.

Results: Amphibians

Volunteers have documented 8 species of amphibians (3 salamanders and 5 frogs) at 113 sites since 2009. During the 2018 season volunteers surveyed 19 sites (figure 6), including 5 known toad breeding locations. Highlights this season include observations of 1 and 2 year old juvenile toads in the Three Lakes area and observations of newly metamorphosed toads dispersing from their natal pond at the littorals. Preliminary results from data collected at 3 toad breeding sites indicate different rates of larval growth suggesting environmental factors – such as seasonal wetland drying – may impact larval development and time to metamorphosis.

A map of Mount Rainier with different terrain (wetlands, meadows) shaded in different colors and survey sites marked with red dots.
Figure 6. Survey sites are located throughout Mount Rainier National Park.

2016 Accomplishments

  • Completed surveys at 19 sites throughout Mount Rainier (Figure 6)
  • Monitored western toad larval development at 3 active breeding sites
  • Documented changes in ephemeral amphibian breeding habitat
  • Monitored northwestern salamander mortalities
  • Collected dragonfly larvae at 3 sites for the Dragonfly Mercury Project

Interested in Helping?

Each summer from July through September we need volunteers to help conduct our surveys. The Citizen Science program gives volunteers of all ages the opportunity to hike and explore some of Mount Rainier’s lakes and wetland habitats while gaining experience in surveying and science. Previous experience is not needed and surveying equipment will be provided. Free camping is available for volunteers at park campgrounds.


(last updated November 6, 2018)

Last updated: November 6, 2018