Flatwoods Salamander Headstarting Project

flatwoods salamander larvae underwater by Pierson Hill

The Apalachicola National Forest is considered one of two remaining population strongholds for the frosted flatwoods salamander. However, recent comprehensive surveys have indicated precipitous population declines and extinctions. In response to this alarming trend, FWRI biologists implemented a “headstarting” program in cooperation with the US Forest Service. The goal of headstarting is to artificially increase the survival rate of larval salamanders in hopes of maintaining or increasing the size of local populations while their breeding habitats can be restored. The presence of a headstarting program also mitigates the effects of La Niña-associated winter droughts, which often results in complete reproductive failure. Natural survival rates of larvae are estimated to be less than 10% but headstarting methods have increased larval survival to over 80%.

Following the arrival of rainy cold fronts in October and November, we began diligently searching known breeding ponds for flatwoods salamander eggs. Flatwoods salamanders lay their eggs in small clusters beneath lush carpets of fire-maintained wetland plant communities, and it’s these areas that we would focus our searches. Once eggs were located, they were removed from the wild and brought into a laboratory setting where their temperature, moisture, and development could be closely monitored. After 2-3 weeks of embryonic development, the eggs were hatched into water-filled “cattle tank” mesocosms. Aquatic mesocosms create a controlled environment for the gilled aquatic larvae which mimics their natural wetland habitats. Key differences are that mesocosms provide stable water levels, constant food (i.e. aquatic crustaceans), and a predator-free environment. After 4-5 months, the larvae undergo metamorphosis and transform into air-breathing juvenile salamanders. Within 48 hours of transformation, the young salamanders were marked, measured, and released back to the site where they were originally collected as eggs. A subset of breeding ponds were monitored to determine how many headstarted salamanders returned as adults to breed.

Over the course of the project (2017-2022), we released over 4,500 headstarts. However, return rates (1%) were not exceeding adult mortality (30-50%) so population declines continue. The US Fish and Wildlife Service and other partners are carrying on these efforts moving forward.

An FWC biologist located salamander eggs at the edge of a dry breeding pond.

a man searches through grass looking for salamander eggs

An array of “cattle tank” mesocosms used to raise larval flatwoods salamanders.

multiple tanks in a field which are used to raise larval flatwoods

A cluster of flatwoods salamander eggs nearing hatching age. The developing embryos are clearly visible through the clear membrane. The embryos will hatch from the eggs within an hour of being submerged in water.

A large larval flatwoods salamander foraging for food at night in a mesocosm. Flatwoods salamander larvae have gills for breathing underwater and have vivid brown stripes for blending in with underwater grasses.