Amphibians in the City

Amphibians are a key indicator species of ecosystem health. Their presence or absence can tell us a lot about the general health of a wetland or riparian area in addition to giving us a sense of site water and habitat quality. When climatic and hydrologic changes occur in an ecosystem, amphibians are often the first to react. Their thin skin makes them vulnerable to temperature increases, chemical pollutants, disease, and radiation. The combinations of pollutants, habitat fragmentation and development in urban areas have had a negative impact on amphibian populations. In the Portland Metro area, everything from mutations of extra legs to complete absence of native amphibians has been documented.

A beaver dam breached by vandals at our Hedges Creek Preserve in Tualatin left several Northwestern Salamander egg masses lying in the drying mud, exposed to the sun. This was the first siting of egg masses at the site. Working with a local amphibian expert and volunteers, we found over 60 egg masses. This discovery encouraged us to consider the interrelationship between beaver dams and amphibian egg masses, conduct more surveys and better document amphibian presence and absence at our preserves and catalogue the habitat and conditions where they are both found and absent.

Over the next year we will be training volunteers to conduct egg mass surveys at TWC preserves and some neighboring wetland and riparian areas. The survey results and analysis of critical habitat elements will be incorporated into setting desired future conditions and subsequent enhancement and restoration projects to meet them for each preserve. Surveys will be conducted annually to track change over time in response to enhancements, restoration or natural climatic variations. This information will be used to prioritize preserve restoration goals and distinguish good areas that should be conserved.

Volunteers will continue to help staff enhance and restore our urban preserves. These projects will involve removing invasive species and trash, improving water flow, and documenting wildlife and macroinvertebrate use. We are excited to create and share some best management practices for improving amphibian and wildlife habitat in urban wetlands for use by our partners and volunteers involved in this and future projects.

Are you interested in working on this project? Contact TWC urban land steward Megan Garvey for more information!
Megan Garvey : megangarvey@wetlandsconservancy.org

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