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Some good news for the Frosted Flatwoods Salamander

This adorable amphibian is a Frosted Flatwoods Salamander (Ambystoma cingulatum). Listed under the US Endangered Species Act as ‘Threatened’ in 1999, populations since then have declined by 90% and now the salamander faces imminent extinction.

The Frosted Flatwoods Salamander in the Southeastern United States is a mysterious species that spends almost its entirely life in secrecy underground. Most people have never seen, or have even heard of this amphibian, and yet it is facing extinction — primarily due to habitat loss, climate change, and fire suppression (yes, these salamanders are fire-dependent!)

A Frosted Flatwoods Salamander from the world’s only captive colony in Atlanta, GA USA at the Amphibian Foundation.

In 2014, a US federal Recovery Team for the species determined that the salamander was at such risk, a captive assurance colony needed to be established to ensure the species could be safeguarded in captivity, while conservation and restoration measures could be employed in the field. Staff at the Amphibian Foundation (AF) were tasked with developing husbandry protocols that could be used to keep the species alive in captivity, while working within a larger group of conservation partners working on other aspects of the salamander’s recovery (Such as US Fish & Wildlife, US Geological Survey, Georgia Department of Natural Resources, Florida Fish & Wildlife, San Antonio Zoo’s Center for Conservation Research, Virginia Tech, and others). At that time, the goal for AF was merely to maintain a genetic repository for Frosted Flatwoods Salamanders, given their precipitous decline in the wild.

Over the next few years, AF focused on building a captive colony, although animals were so rare and difficult to detect, that the first few years yielded less than a handful of animals. Partners in the field from their last known habitats, such as US Army Biologists at Fort Stewart, GA USA and Florida Fish and Wildlife began monitoring the drought conditions in the southeast, and alerted staff at the Foundation when eggs were drying in the field, or when wetlands were drying out too quickly, and the larvae would not have time to metamorphose. These rescue missions supplied the majority of the founding stock for the captive colony.

In 2017, AF had completed the Amphibian Research and Conservation Center, which is an outdoor laboratory with 33 artificial and experimentally controllable wetlands called mesocosms. The mesocosms hold many breeding groups of Flatwoods Salamanders as well as other native imperiled amphibian species. While we have had reproductive behavior and some encouraging results (e.g. spermatophore deposition) no eggs have been laid in the mesocosms, and the breeding season is currently ending. Maybe next year!?

The biosecure Salamander Lab at the Amphibian Foundation, including the ‘indoor mesocosm’ (left) and 3 ‘ecotonal rainchambers’ (right)

While the majority of the captive colony is housed in the outdoor mesocosms, there are some salamanders which have been lab-reared for indoor captive spawning experiments. In 2020, we introduced 12 larval Frosted Flatwoods Salamanders into the indoor mesocosm (pictured above) so they could complete metamorphosis in the indoor habitat which was modeled after their native Longleaf Pine ecosystem. The mesocosm contains vegetation from their breeding microhabitat, including plants that the species is known to nest under. We introduced them as larvae because certain Ambystoma exhibit site fidelity, meaning they return to their natal pond each year to breed. Certain congenic salamanders imprint on their natal wetland at metamorphosis, and so we considered this when developing our conservation strategy.

What you are seeing here are the first eggs ever produced in captivity for the Frosted Flatwoods Salamander — an imperiled species considered at imminent risk of extinction. These eggs were produced by the salamanders in an ecotonal rainchamber at the Amphibian Foundation.

Another group of lab-reared Frosted Flatwoods Salamanders were raised individually and carefully monitored (monthly weights and measurements and veterinary inspections). In the fall of 2021, some of the salamanders were exhibiting secondary sexual characteristics and so were placed carefully into ecotonal rainchambers, which is a breeding environment developed at the Amphibian Foundation to encourage spawning of salamanders which naturally nest in the ecotone, or the graduation between the wetland and the upland. For species that nest in the ecotone, only significant rain events fill the ponds high enough to reach the eggs, and this maximizes the chances that the wetland will hold water long enough for the larvae to complete metamorphosis.

It was this third strategy (individually lab-reared salamanders, introduced in breeding condition to the rainchambers) which paid off first. 6 weeks after they were introduced, we detected eggs in the rainchamber — and they looked good! We were thrilled to witness this as we have been focused on this species for many years, and have finally produced some captive offspring. About a month later, a second group produced eggs in another rainchamber, and weeks after that — eggs in the indoor mesocosm!!

That’s 3 breeding groups of salamanders in two distinct spawning strategies that produced eggs. We are beyond excited and have immediately begun the next phase, as established by the Recovery Team in 2014, which is to identify partner organizations who would like to work with us to build up the numbers of Frosted Flatwoods Salamanders produced in captivity, which will greatly increase our chances to successfully reestablish them into protected habitat in the wild.

Thank you for the opportunity to share a little good news with you all!!!

For the amphibians,

Executive Director, Amphibian Foundation

A Frosted Flatwoods Salamander embryo hatches in a single drop of water.