Italian cave salamanders in Germany?
© Carl-Henning Loske
Non-native species are among the main problems for biodiversity loss. Among amphibians, it is especially some non-native frogs that can have a great negative impact on alien ecosystems. Since 2013, it has been known that there is a small population of cave salamanders in Weserbergland/Solling, Lower Saxony. Now the species is determined by genetic evidence to be Speleomantes italicus.
The cave salamanders of the genus Speleomantes are endemic to France and Italy. Three of the species occur along the Apennines in mainland Europe, while the other five species are distributed in Sardinia. Despite the trivial name cave salamander, the caudate amphibians are not limited to these and also inhabit other habitats such as mines or rock crevices, where a permanently damp and cool climate prevails all year round. This microclimate is necessary because cave salamanders belong to the group of lungless salamanders (Plethodontidae) and absorb the oxygen they need through their skin.
Since 2013, it has been known that there is a small population of cave salamanders in Weserbergland/Solling, Lower Saxony. However, since the eight species of cave salamanders are extremely similar purely in appearance and therefore difficult to determine, the exact species affiliation of the animals there was unknown and further investigations were also lacking. It was also unclear whether it was a reproducing, established population or just a few animals that had survived there for several years. For this reason, biologists Philipp Ginal from the Leibniz Institute for the Analysis of Biodiversity Change (Herpetology) and Carl-Henning Loske (Ingenieurbüro Loske) visited the study area in Lower Saxony several times to also photographically document as many cave salamanders as possible.
Last autumn, the researchers were able to discover and photograph a total of 70 different individuals of cave salamanders. Three of the animals were also found on a second trapping date. Loske explains: “Since cave salamanders have a very complex and individually unique colour pattern, the identification of single individuals is possible”. Together with colleagues Dennis Rödder from the Leibniz Institute for the Analysis of Biodiversity Change (Herpetology) and Thomas Hörren from the University of Duisburg-Essen, the researchers estimated the population size, i.e. the number of individual animals, using so-called catch-recapture models. “According to our results, the German population comprises between 170 and 485 animals and is thus significantly larger than previously assumed. However, the minimum value of 170 is rather unrealistic and we assume that there are considerably more individuals,” explains Ginal.
Furthermore, a recently published, extensive photo database was used to make a first morphological determination of the species. The photo database used includes more than 1000 images of all cave salamander species from different local populations. “In addition, the comprehensive photographic comparison with the database showed that of the eight known species, only populations of the species Speleomantes italicus are identical to the German animals. This species occurs in the northern and central Apennines,” explains Rödder.
In the meantime, colleagues at the University of Braunschweig have been able to confirm the species affiliation through genetic studies. Both research teams were also able to detect several juveniles and a pregnant female of the species during their field work, thus providing definitive proof of reproduction. As cave salamanders are not native to Germany, future monitoring of the population is necessary. So far, however, the population there is restricted to a rock face of about 40 m. Competition with native amphibians or other negative impacts of the species on the native fauna could not be proven so far. Sometimes the cave salamanders have even been found together with the native fire salamanders or Alpine newts in the same crevice.
Contact:
Philipp Ginal
Leibniz-Institut zur Analyse des Biodiversitätswandels
PhD student
Herpetology Koenig Museum
E-Mail: philipp.ginal@gmx.de
Dr. Dennis Rödder
Leibniz-Institut zur Analyse des Biodiversitätswandels
Section Head Herpetology Museum Koenig
Curator
Herpetology
Tel:+49 (0)228 9122 252
E-Mail: d.roedder@leibniz-zfmk.de
Thomas Hörren
University of Duisburg-Essen, Faculty of Biology, Aquatic
Ecology, Universitätsstraße 5, 45141 Essen, Germany
thomas.hoerren@koleopterologie.de
Carl-Henning Loske
Publicly appointed expert for environmental impact studies
Office Landscape & Water
Salzkotten-Verlar
Tel: +49 (0) 29 48 / 2 90 51 und 2 90 52 ·
info@buero-loske.de
