The Fate of the Frogs
We’re finding allies in amphibian conservation.
Less than a mile from the wastewater treatment facility in North Portland sits a white bungalow home with turquoise shutters. Whirring traffic buzzes by and the business of humans continues on, but what lies in the fenced-off backyard of this humble home is an unexpected sanctuary. In a seven-by-four-foot blue pool is a mini-wetland maturing with life and about a dozen frog egg masses. Seemingly insignificant on a regional scale, ponds like these have developed into critical habitat for frogs and other amphibians in an increasingly urban scene.
“My family thought I was crazy for wanting to set up the pool,” Nancy Whitmore says, “but I had to at least try.”
Whitmore’s yard boasts tall grasses and native shrubs and is certified by the Backyard Habitat Certification Program, a partnership between Columbia Land Trust and the Audubon Society of Portland.
Just a few months after the pond’s installation, Pacific tree frogs (Pseudacris regilla), also known as chorus frogs, began moving in and laying eggs. “People visit and ask where I bought the frogs,” Whitmore says with a crooked eyebrow. “We all seem to forget that these species can thrive in a metropolitan space.” Indeed, as more local wetlands succumb to development, urban habitats are playing a larger role in frog conservation. Frogs serve an invaluable role as bio indicators. As cutaneous breathers (exchanging gas across their skin), they are often one of the first species to signal climate, air, and water quality changes with their weakening.
The Oregon spotted frog (Rana pretiosa), a sensitive species adapted to warm and large marshes with aquatic plants, is federally listed as threatened by the U.S. Fish and Wildlife Service. It has been extirpated in nearly 78 percent of its former habitat due to habitat loss, pollution, predation by exotic bullfrogs, and invasive non-native plants, such as the aggressive reed canarygrass (Phalaris arundinacea).
Columbia Land Trust has worked for several years to restore wetlands, including eradicating reed canarygrass at Indian Jack Slough, a wetland within the Lower Elochoman watershed. In 2012, 11 acres were removed, provisionally freeing the marsh of the tenacious species. Contouring made way for mounds and depressions, allowing the native sea bank to flourish and protected habitat spaces to emerge. A year later, in 2013, citizen scientists and Land Trust stewards surveyed over 4,000 northern red-legged frog (Rana aurora) egg masses.
Stewardship Lead Jeff Malone said the team has installed thousands of native plants in the associated uplands and will place woody debris along the windward water borders to provide breeding and basking habitat for amphibians and other wildlife this fall.
While the Land Trust focuses on protecting and restoring wetlands, others are helping bolster area frog populations. The Sustainability in Prisons Project, which is facilitated by Evergreen State College and the Washington Department of Corrections, is one such group. Since 2009, inmates at the Cedar Creek Correction Center in Littlerock, Washington have reared and released 625 Oregon spotted frogs. The minimum-security facility partners with the U.S. Fish and Wildlife Service, local parks, and zoos. Inmates work six hours per day alongside biologists and graduate students, feeding the frogs, participating in research, and releasing plump and prepped frogs throughout Pierce County.
But frogs in the region face yet another challenge in the form of water pollution. The City of Gresham Watershed Restoration Coordinator and Natural Resource Ecologist for the City of Portland, Laura Guderyahn, has worked in wetland restoration since 2006 and has surveyed over 250 public and private ponds throughout Gresham, Portland, and Vancouver.
Since 2008, her team has monitored high rates of malformation in various frog species at seven sites across Hillsboro, Beaverton, Gresham, and Clark County. Fertilizer runoff into aquatic habitats produces excess phosphorus. Algae blooms quickly, and snails consume it, producing waste where dense and infectious parasite populations proliferate. The parasites affect the development of neighboring egg masses and tadpoles that metamorphose into young adults sometimes with extra, bent, or no legs. Guderyahn sends samples to the Johnson Lab at the University of Colorado Boulder, where researchers are studying the consequences of the pathology and population persistence.
Still, Guderyahn says ponds like Whitmore’s are a reason to stay positive. “We might not have many of the specialist species, such as the Oregon spotted frog,” she said, “but creating habitat in urban areas allows us to have some amazing species living and thriving ten feet out our back doors.”
As traffic dies and dusk arrives, Whitmore’s frogs swell to a crescendo, creating a calming euphony in unison, almost as if they’re expressing thanks for their new surroundings. The family dozes off as the wind carries the chorus into their home through half-open windows. They’re eager to witness changes in the pool in the coming weeks.