Arlington’s Amphibian Resurgence
Arlington County, Virginia is very urbanized. Due to loss of wetlands (including vernal pools) and heavy development, half the frog and toad species that used to live in Arlington are now gone. The remaining species are often in small, isolated populations, in only a handful of locations.
Frogs and toads are excellent bio-indicators of environmental health. Since they consume plant material when young and then switch to a predatory diet, they can build up toxins in both diets. Since they can also absorb chemicals and pollutants through their skins in all stages of life, they are also very sensitive to changes in the environment. So loss of frogs and toads can point to an unhealthy environment and their declines can serve as a warning about the state of the habitat.
In addition to having cleaner water and preserving our wetlands, the control and management of invasive plant species has allowed the habitats to support more insect food. Native plants that have also been making comebacks support more insect prey than the exotic invasive plants (and these insects then feed so many more animals such as most of our bird and all our bat species).
Some of our frogs needed a bit more help in getting established. Such was the case for our Wood Frogs which are dependent on mostly fish-free vernal ponds and mature woodlands. For the longest time Arlington only had two places where they bred. In time, the population from Long Branch Nature Center eventually made it into Glencarlyn Park on its own. But since these frogs need mature woods and vernal ponds that may not be close to one another, we assisted in establishing new populations.
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