Green Salamander Project (Aneides aeneus)

The Green Salamander (Aneides aeneus) is a cryptic species of lungless salamander that is rarely encountered in Tennessee. The species is a habitat specialist whose primary habitat is along sandstone rock outcroppings where they are found inside of narrow crevices. The species is occasionally found on limestone outcroppings and, more infrequently still, under logs and in trees. This is the only species of salamander in eastern Northern America that has a green coloration, which makes excellent camouflage around the moss-covered, shady rock outcroppings it calls home.

Unfortunately, Green Salamanders face a variety of anthropogenic threats and, overall, the species is thought to be declining across its range. Disease caused by the Chytrid fungus and Ranavirus are leading to mass extinctions of amphibian species across the world, and both diseases have been found in the Green Salamander. While disease is certainly a major threat, habitat loss and fragmentation is likely the greatest threat to amphibians, including the Green Salamander. Threats to habitat can isolate populations and inhibit the flow of genes which can lead to dramatic population declines.

In 2012, the U.S. Fish and Wildlife Service was petitioned to protect the Green Salamander under the Endangered Species Act. After an extensive review process, the U.S. Fish and Wildlife Service announced in 2015 that protection may be warranted. In order to make an accurate assessment of the species’ conservation status, knowledge gaps concerning many aspects of its demographics (population size, natural birth and death rates) and ecology must first be filled.

To fill these knowledge gaps, the Tennessee Wildlife Resources Agency (TWRA), in partnership with five other states representing the core of Green Salamander geographic distribution, applied for and received a competitive State Wildlife Grant from the U.S. Fish and Wildlife Service. The three primary objectives of the research are to: 1) survey historical occurrence records and document new occurrences of the species, 2) assess the prevalence of disease, and 3) evaluate the genetic structure of the species across its range. The TWRA then partnered with the University of Tennessee at Knoxville to conduct the disease aspect of the study and with the University of Alabama at Huntsville to conduct the genetic analyses.

TWRA biologists and their university partners will survey numerous areas across the eastern two-thirds of the state including Wildlife Management Areas (WMAs), State Parks, State Natural Areas, State Forests, and private lands in search of the elusive Green Salamander. The basic method for finding the species involves walking along bluff lines and rock outcroppings, and peering into crevices with flashlights.

Once an individual is found, researchers use zip ties to coerce the salamanders out of the crevice and into a single use zip-lock bag. While in the bag, measurements are taken along with swab samples that will be sent to the University of Tennessee for disease testing. Also, a small section of the end of the tail is severed off for genetic sequencing at the University of Alabama. Finally, the salamanders are released back into their crevice.

Ultimately, protecting a species under the Endangered Species Act is a costly and time consuming endeavor, and the primary goal of the State Wildlife Grant Program is to provide research that will keep species from being listed unless protection is absolutely critical. At the conclusion of this research, we will have a much better idea of how disease is impacting Green Salamanders across their range and if populations are being isolated enough to halt gene flow across populations. As the other objects of this research are fulfilled, we will be in a much better position to not only assess the conservation needs of Green Salamanders, but also focus our conservation strategies to best ensure the persistence of these colorful amphibians for generations to come.