A Plague for Salamanders
The Nuremberg Zoo has been committed to protecting local fire salamanders since autumn 2020. These salamanders are threatened by a new, deadly skin fungus: the “salamander killer” Batrachochytrium salamandrivorans (Bsal for short). The fungus probably came to Europe from Asia and continues to spread. It was first detected in the Bavarian national park Steigerwald in the summer of 2020. So as not to stand idly by as infected animals in this local population perish, through the initiative of Mark-Oliver Rödel, president of Frogs & Friends, all animals that were tested positive were brought to the Nuremberg Zoo in autumn 2020 to quarantine in the zoo’s outdoor station. Fortunately, although nearly 100% of salamanders in the wild die of the infection, BSal ist treatable in human care at least – with a strict two-week heat therapy at a constant 25°C.
Successful therapy in the Nuremberg Zoo
Housed individually in hygienically equipped containers, five infected fire salamanders were moved into a heating cabinet for two weeks. To be on the safe side, they then spent a further 12 weeks in quarantine. During the entire treatment period, the containers and furnishings were disinfected daily.
The salamanders’ body weight was recorded every other day to ensure an early reaction in the event of an alarming weight loss. Fortunately, during the subsequent regular check-ups, the fungus was not detected again.
All of the animals, even including a salamander baby weighing just three grams, have recovered. They are now supposed to lay the foundation for large-scale ex situ conservation breeding. It’s looking good: one of the animals is pregnant. How do we know this? Fire salamanders are the only caudates to give birth to living larvae, and the zoo experts were able to make them visible using an ultrasound.
Outlook: Conservation of local fire salamander populations
Since we can assume that the fungus will continue to spread in the Steigerwald, we are working to build a “reserve population” in human care. In case the fire salamanders are completely wiped out, as in other affected regions, we will still have salamanders that can be reintroduced into the wild later when the danger has dissipated.
We don’t know when that might happen. Infested areas are lost to fire salamanders for years or even decades. The fungal spores can persist for a long time in these ecosystems – even in other amphibians such as newts, which do not necessarily die from it. It remains to be seen whether BSal will eventually disappear from infested habitats or whether fire salamanders will develop a resistance to it – naturally or artificially.
In any case, there is only one option left to save affected fire salamander populations: a coordinated conservation breeding program! Citizen Conservation wants to rise to this challenge.