Collaboration with U.S. Air Force helps restore, protect endangered salamander
August 25, 2020
In April of this year, young salamanders emerged from two northwestern Florida wetlands where they hadn’t been seen in over a decade. Their presence is the result of a long-term collaborative recovery effort between Virginia Tech and Eglin Air Force Base.
The project has led to an increase in the numbers and distribution of federally endangered reticulated flatwoods salamanders in the Florida panhandle and offers potential new avenues for conservationists to successfully bring back endangered amphibians.
“Military bases typically harbor more endangered species by count than national parks or wildlife refuges,” explained Professor Carola Haas of the College of Natural Resources and Environment, lead researcher on the project. “That’s partially because bases are more often managed with prescribed fire and partially because there are limits on human access to the land.”
Those limits have made Eglin Air Force base, located in one of the last remaining old-growth, longleaf pine regions in North America, a crucial habitat for 63 plant and animal species listed as globally rare, including the red-cockaded woodpecker, the Florida bog frog, and a fish known as the Okaloosa darter. It is within this crucial ecosystem, hidden among seasonal ponds and under leaf litter, that a rare amphibian clings to survival.
Tracking an elusive animal
With a web of silvery gray lines crisscrossing over brown-black skin, reticulated flatwoods salamanders are visually striking, but finding them is a challenge. A species of mole salamander, adult flatwoods spend most of their lives underground, avoiding the midsummer heat of the Florida panhandle. They are even more difficult to find in their younger stages.
“Finding eggs for these salamanders is an amazing feat,” said Haas, a faculty member in the Department of Fish and Wildlife Conservation. “Unlike a lot of frog and salamander species that lay eggs in sizable clumps, this species lays their eggs individually or in groups of two or three. Each one is clear and smaller than a green pea, and they’re typically laid in dense vegetation, so it’s a real challenge.”
It is a challenge that Virginia Tech researchers, working under the direction of the Eglin Air Force Base’s Natural Resources Office and in collaboration with the Air Force Wildland Fire Branch’s Eglin Wildland Support Module, U.S. Fish and Wildlife Service, Florida Fish and Wildlife Conservation Commission, Longleaf Alliance, and Georgia Southern University, have managed to meet.
The result is a multifaceted management program tasked with everything from finding eggs and larvae, to participating in prescribed burns and working with hand tools to improve habitat, to partnering with agencies for large-scale restoration work with excavators to create new habitat. This implementation of a range of management practices as part of controlled experiments, combined with using statistical models to assess the likely outcomes, are powerful tools that help focus efforts on the strategies most likely to yield success.
Restoring wetlands to bring salamanders back
As naturally occurring fires were suppressed over the past century, wetlands that would normally have an open canopy and grassy understory have become choked with shrubs, gradually becoming inhospitable to flatwoods salamanders and their invertebrate prey. To combat this, Virginia Tech’s field crew has worked with partners to restore habitats around Eglin to a more suitable condition, while researchers on campus have worked on population models to better understand why flatwoods salamander populations are declining.
Research has shown that flatwoods salamanders have very limited dispersal. With each wetland or small cluster of wetlands functioning semi-independently, subsequent analyses showed that salamander populations in isolated wetlands were much more likely to become extirpated (go extinct locally) than populations with clusters of six or more wetlands located nearby.
Such stark results suggested a need for drastic actions to restore the salamanders to their former breeding range on the base. Over the past 10 years, Virginia Tech and Eglin have partnered with several agencies, nongovernmental organizations, and private contractors, as well as put in a lot of their own crew’s “sweat equity,” to remove woody vegetation and accumulated peat from many wetlands across the base. Eglin and the Florida Fish and Wildlife Conservation Commission brought in heavy equipment to excavate overgrown woody growth and peaty root mat from severely degraded wetlands in order to create better clustering of ponds. This “stepping stone” design connects occupied wetlands with suitable but unoccupied wetlands.
Still, some parts of the base were too far from other occupied wetlands, so researchers have begun the practice of translocating animals into those ponds. Their aim is to recolonize those habitats within this century.
Starting in January 2020, Virginia Tech researchers collected eggs and larvae from wetlands where they were abundant. After holding them for two or three weeks in order to hatch the eggs and gather enough larvae, the animals were released into two long-vacant wetlands. If larvae were found to survive in the ponds for a few weeks, the team would consider it a qualified success.
“After years of deliberation, we got to the point where we realized we’d be well-suited to trying something new,” explained Rodney Felix, an endangered species biologist at Eglin. “We had the chance to test some concepts to see whether or not it’s possible to put these animals in new habitats and see if they’re able to survive and continue the species.”
The early results from the work are positive: not only were surviving larvae observed on biweekly checks, but metamorphosed salamanders were found in two ponds on the base where they hadn’t been found before. This is evidence that larval animals have successfully managed their transition into land-dwelling adults, a crucial step towards species self-sustainability.
“Both of these ponds have been the focus of habitat restoration efforts occurring in several stages over the past 10 years,” said Kelly Jones, research associate at Virginia Tech and leader of the Florida field crew. “We’ve addressed the degraded habitat conditions implicated in the original disappearance of the species from this reintroduction area.”
The next step for researchers is to capture the surviving translocated adults and conduct genetic testing to see what kind of pond they originated from. This will allow researchers to see whether flatwoods salamanders have microgeographic adaptations that result in better survival if their new wetland is similar to their wetland of origin, or if larvae from any wetland can do equally well in new environments.
“Conserving genetic diversity across the landscape is important to long-term survival,” Haas noted, “especially knowing that these populations are vulnerable to climate change and emerging disease threats.”
Felix added, “Without a doubt, we couldn’t do what we’re doing with salamander recovery without the contributions of Virginia Tech. They’ve done all of the egg and larval collection, as well as the monitoring of animals.”
The team of researchers involved have shown both persistence and a key willingness to adjust and adapt conservation strategies to better suit conditions at Eglin. Their success in increasing flatwoods salamander populations on the base will provide critical information about ways that conservationists can more effectively and efficiently protect endangered amphibian populations around the world.
Written by David Fleming