Connect with Metro
503-797-1804 TDD
503-797-1797 fax

Amphibian monitoring

Planning and conservation    Natural areas, parks and trails    Restoring the landscape    Wildlife monitoring    Amphibian monitoring

Amphibian monitors gather data from egg mass surveys to help track sensitive species populations and gauge results of restoration at Metro natural areas.

Photograph of volunteer amphibian monitors

Metro has initiated several floodplain restoration projects in the region since the open spaces, parks and streams bond measure was passed in 1995. To help gauge the effectiveness of these projects, Metro is tracking pond-breeding amphibian populations with the help of dozens of dedicated volunteers.

Beginning in February when pond water closely resembles ice water, volunteers search for jelly-like egg masses to collect information about the distribution and abundance of native pond-breeding amphibians such as the state sensitive northern red-legged frog (Rana aurora aurora). The data collected by the amphibian monitors not only helps Metro assess the effectiveness of current restoration work, but also guides management actions and helps to raise grant funds for ongoing restoration work. Other species tracked include the exotic bullfrog (R. catesbeiana) the northwestern salamander (Ambystoma gracile), the long-toed salamander (Ambystoma macrodactylum) and pacific chorus frog (a.k.a. Pacific treefrog, Pseudacris regilla).

Photograph of Pacific chorus frog

Initial findings are encouraging. Volunteers have tracked red-legged frogs as they have expanded throughout nearly 100 acres of newly restored seasonal floodplain wetlands at Metro’s Multnomah Channel Natural Area where Metro partnered with Ducks Unlimited, the U.S. Fish and Wildlife Service and the Natural Resources Conservation Service to install two water control structures. In 2004 volunteers documented more than 100 new red-legged frog masses at its newly restored Gotter Prairie Natural Area. In 2006, volunteers tracked expansions of red-legged frog breeding activity in the Coffee Lake Bottoms Natural Area. For more information about current findings, read Metro's annual amphibian monitoring reports...Download monitoring reports below

Photograph of an egg mass

Volunteers are asked to conduct at least four surveys during the two months during the peak of the breeding season. Total time commitment ranges between 15-25 hours. In 2006, fifty-seven volunteers surveyed 10 sites contributing over seven hundred hours to the project.

Program information

Download project reports, datasheets, monitoring protocols and other information about the amphibian monitoring program below

2005 and 2006 monitoring reports

These reports provide a brief overview of the Metro amphibian egg mass monitoring program and present summaries of the data collected through the 2005 and 2006 seasons. Most of the data presented in the report were collected by volunteers working under Metro's direction.

Photograph of Pacific chorus frog

Amphibian monitoring protocol

Learn about the sampling methods used to monitor pond-breeding amphibian egg mass abundance and distribution at targeted restoration sites.

Amphibian survey datasheet

See a sample of the datasheet used for egg mass surveys.

Related Documents

To view PDF files, download free Adobe Reader. To translate PDF files into text to assist visually-impaired users, visit

To view MOV files, download free QuickTime.

Need assistance?

Katy Weil

© 2014 Metro. All rights reserved.

Send questions, comments and suggestions about the website to

600 NE Grand Ave.
Portland, OR 97232-2736
503-797-1804 TDD
503-797-1797 fax