Amphibians

A Quick Look

Amphibian populations are fairly stable.

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Wood frog (Rana sylvaticus) eggs attached to a slim reed. Photo: NPS

Importance and Issues

Amphibians (frogs, toads, and salamanders) are good indicators of environmental changes. They are closely tied to both land and aquatic habitats and are sensitive to factors such as pollution, drought, habitat loss, and disease. In the rapidly urbanizing region around Washington, DC, the potential for multiple and interacting stressors is significant. These factors may cause changes in amphibian distribution, numbers, and the diversity of species at a given site (species richness). They may also cause increases in diseases and malformations.

Amphibians play an important role in the food web, serving as prey for many fish, reptile, bird, and mammal species and in turn eating a wide variety of vertebrate and invertebrate species.

Jump to how we monitor amphibians.

Monitoring Questions and Approach

• Of the amphibians found in the park, which species are stable, increasing, or decreasing?

• How widespread is each amphibian species across stream and wetland pool habitats?

• What are possible threats to amphibians?

• What are potential management actions that can protect amphibians?
  
  Detailed monitoring objectives from our protocol document are found here.

Reports, Data & Protocol

Source: Data Store Saved Search 1295. To search for additional information, visit the Data Store.

Resource Briefs
Summaries of fieldwork and findings

Source: Data Store Saved Search 1266. To search for additional information, visit the Data Store.

How We Monitor

National Capital Region Network monitors amphibians in both streams and wetlands. Wetlands are visited four times a year—twice in spring to do visual surveys for egg masses and adult amphibians and twice in summer to dip-net for larval amphibians. Streams are visited twice each year—leaf litter is searched and cover objects are turned to find adult salamanders. Any amphibian malformations are recorded.

Measures of amphibian populations include: proportion of area occupied and occupancy. Calculations take into account variations in the likelihood of detecting species at a site due to their behavior, habitat, and other variables. These measures also allow us to test specific hypotheses about factors influencing amphibian distributions.

Wetland Amphibian Monitoring by Park and Year

 

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

2017

2018

2019

2020

2021

Antietam NB

x

Catoctin Mountain Park

x

x

x

x

x

x

x

C&O Canal NHP

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

x

GW Memorial Parkway

x

x

x

x

x

Harpers Ferry NHP

x

x

Manassas NB

x*

x*

x*

x*

x*

x*

x

x

x

x

x

x

x

x

Monocacy NBP

x

x

x

x

x

x

x

National Capital Parks - East

x

x

x

x

x

Prince William Forest Park

s

s

s

s

s

x

x

x

x

x

Rock Creek Park

x*

x*

x*

x*

x*

x*

x*

x*

x*

x*

x*

x

x

x

x

x

x

Wolf Trap NP for the Performing Arts

* indicates that only a subset of species were identified. "s" indicated stream sampling only.