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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 have 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 begin 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 focus our searches. Once eggs are located, they are removed from the wild and brought into a laboratory setting where their temperature, moisture, and development can be closely monitored. After 2-3 weeks of embryonic development, the eggs are 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 are marked, measured, and released back to the site where they were originally collected as eggs. A subset of breeding ponds are monitored to determine how many headstarted salamanders return as adults to breed.

Since 2017, we have released 4,638 headstarts. However, return rates (1%) have not exceeded adult attrition (30-50%) so population declines continue. It appears that post-release survival and/or recruitment is too low to prevent population declines. Additionally, extreme weather events (e.g. winter droughts) have prevented appreciable natural reproduction in 4 our of 5 project years. To increase the number of individuals successfully recruiting into breeding populations, it will be necessary to incorporate captive bred eggs and larvae into the headstarting program. Stay tuned for future updates on these efforts.