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I am an Associate Professor at the Biogeography Department of Trier University,
Germany, and the PI of several research projects related to
   - species genesis and delimitation, including geographic range exploitation,
   - character evolution, in particular traits related to aposematism,
ecological niche exploitation and change,
   - biological response to past and future landscape or climate change as well as
      to human impact including pesticide applications,
   - the impact of invasive species and pathogens.

Focal study regions are rainforests of South America and Africa but also our 'back garden' in central Europe. Our key organisms are amphibians. Among our main study groups are poison frogs (Dendrobatidae), harlequin toads (Atelopus), reed frogs (Hyperoliidae) and European land salamanders (Salamandra). But these are not exclusive, as we also investigate reptiles, invertebrates or others. We study species and their environments at different spatial, temporal and taxonomic scales.

In an interdisciplinary frame, our lab may best be seen at the interface of systematics, ecology, biogeography, evolution and conservation. Methodically, we make use of modelling, GIS applications, (molecular) phylogeny etc. and process lab, experimental and field data. We very much like collaborative work!

Lötters is an editor of PLoS ONE and Salamandra. He is member of the IUCN Species Survival Commission, the 'Biodiversity, GMO-Monitoring and risk management' committee of VDI, and he is co-speaker of the 'Arbeitskreis Biogeographie'. He was an editor of Biotropica, a member of the International Committee of the World Congress of Herpetology and the vice-president of the German Herpetological Society DGHT.

My ORCID (Open Researcher and Contributor ID) is orcid.org/0000-0002-7187-1968. I am also on Research Gate.

Lab News and Research Highlights

These Soles are Made for Walking


The diversity of strategies by animals to avoid predation is fascinating. We studied diurnal, toxic harlequin toads, Atelopus spumarius sensu lato, from the Amazon basin. In this species complex, some populations have striking red soles of the hands and feet, visible only when walking (see video). When stationary, the toads are hard to detect. Consequently, these toads switch between high and low conspicuousness. Interestingly, some populations lack the extra colour display of the soles.

In a recent study, lead by Daniela Rößler and published in Scientific Reports, we found comprehensive support that the red coloration can act as an warning signal directed towards potential predators: red soles are significantly more conspicuous than soles lacking red coloration to bird predators and the presence of the red signal significantly increases detection. In line with this, toads with red soles show bolder behaviour by using higher sites in the vegetation than those lacking this signal. Field experiments hint at a lower attack risk for painted frog clay models with red soles than for those lacking the signal, in a population where the red soles naturally occur.

If advantageous, why red soles are absent in some Atelopus populations? Signal lack (evolutionary loss?) may be explained by a higher overall attack risk or potential differences of predator community structure between populations.

Rößler, D.C., S. Lötters, J. Mappes, J.K. Valkonen, M. Menin, A.P. Lima & H. Pröhl (2019): Sole coloration as an unusual aposematic signal in a Neotropical toad. — Scientific Reports, 9: 1128.

New Alarming Discovery: Co-infection of Chytrid Fungi on Amphibians


Emerging fungal diseases are increasingly contributing to the global biodiversity crises. Among the most blatant is chytridiomycosis in amphibians. It can be caused by 2 species of chytrid skin fungi, Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal). We for the first time ever found that both fungi can parasite on the same host individual. Of 22 fire salamanders (Salamandra salamandra) found dead at the "Belgenbach", Eifel (Germany), 21 had Bsal and 16 of them additionally Bd

This is alarming news! In a recent paper we discuss that multi-parasitism can have effects on host susceptibility, infection duration, transmission risk and clinical symptoms. Moreover, 'horizontal gene transfer', already known from Bd and other fungi, may increase pathogen virulence. 

On the other hand, pathogen interaction can also be antagonistic. Moreover, among nearly another 500 fire salamanders from all over Germany Bd - besides its wide geographic spread of Europe - was almost entirely absent. Bsal was confirmed in about 70 of them. Bd/Bsal co-infection definitvely is one of the many research fields in amphibian conservation which urgently need attention!    

Lötters, S., N. Wagner, A. Kerres, M. Vences, S. Steinfartz, J. Sabino-Pinto, L. Seufer, K. Preißler, V. Schulz & M. Veith (2018): First report of host co-infection of parasitic amphibian chytrid fungi. — Salamandra, 54: 287-290.

The Future of Clay Model Studies


Predator-prey interactions can be addressed using clay models of prey animals. These are placed in the field to test the predator’s behavior: attack, avoid or whatever?

Our lab uses clay models to learn more about the function of warning signals in toxic amphibians. For instance we test if attack rates change if a novel signal is involved, such as when in real yellow-black fires salamanders are suddenly blue and black ('fake news' so to say). For various reasons clay model studies are really tricky. In a recent BMC Zoology paper, Rößler et al. comment on such studies in the future including the use of proper (non-toxic) clay materials, standardization and next generation clay model studies. 

Rößler, D.C., H. Pröhl & S. Lötters (2018): Commentary: the future of clay model studies. — BMC Zoology, 3: 6.


James Bond of Biodiversity


The license to kill - are we allowed to drive species to extinction that are transmitters of serious diseases? At least we do so: In the “Pan African Tsetse and Trypanosomiasis Eradication Campaign,” we aim at eradicating the pathogen Trypanosoma via eradication of its vector: tsetse flies. Is this justified, can we decide a species is 'good' or 'bad'? How does this meet with our general goal to globally safeguard biodiversity? We come to the conclusion that disease eradication programs may not be in line with the Convention on Biological Diversity (CBD), which we discuss in a recent policy perspective by Hochkirch et al. in Conservation Letters. The 'License to Kill' might be exclusive to Mr. James Bond in another mission.

Hochkirch, A., J. Beninde, M. Fischer, A. Krahner, C. Lindemann, D. Matenaar, K. Rohde, N. Wagner, C. Wesch, S. Wirtz, A. Zink, S. Lötters, T. Schmitt, A. Proelss & M. Veith (2018): License to kill? – Disease eradication programs may not be in line with the Convention on Biological Diversity. — Conservation Letters, 11: 1-6.

De-Extinction, Nomenclature, and the Law


This week, our group was involved in a policy forum article in Science. People from the Department of Biogeography and the Institute of Environmental  and Technology Law of Trier University contributed to this paper by  Norman Wagner and colleagues. 

Our policy piece deals with de-extinction of animal species which no longer exist on our planet, such as mammoths species. New techniques  -  back-breeding, cloning, and genomic engineering  -  now provide the opportunity to attempt to resurrect extinct species. We discuss implications for conservation laws, which largely depend on zoological nomenclature, and laws regarding the release of genetically engineered species, which do not, and argue for unique naming of de-extinct species.

Wagner, N., A. Hochkirch, H. Martin, D. Matenaar, K. Rohde, F. Wacht, C. Wesch, S. Wirtz, R. Klein, S. Lötters, A. Proelss & M. Veith (2017): De-extinction, nomenclature, and the law. — Science, 356: 1016-1017.


Joint European Forces to Mitigate Problems from Salamander Fungus


Under the lead of Gent University / BE, the European Commission has granted EUR 900,000

for 36 months for the project "Mitigating a new infectious disease in salamanders to counteract
a loss o
f European biodiversity" (No 07.027731/2017/750768/SER/ENV.D.3.). Apart from
Trier University / GER, the following institutions from six countries are partners: Stichting Reptielen Amfibieën Vissen Onderzoek Nederland (RAVON) / NL;
Centre National de la Recherche Scientifique (C.N.R.S.) / F; Universita degli Studi di Genova (UNIGE) / I;
Zoological Society of London / UK; Agencia Estatal Consejo Superior de Investigaciones
Cientifica (CSIC) / ES; NATAGORA / BE.

The goal of this international research project is to collect data at the large scale to better understand the epidemiology of the dangerous salamander fungus, Batrachochytrium salamandrivorans (Bsal) – and to eventually stem the expected tide of amphibian population declines and prevent mass extinctions. A webpage informs about the project.

The part of Trier University is to provide information on the presence/absence of Bsal in Germany. For this purpose, we sample fire salamanders (Salamandra salamandra) at 50 localities all over Germany. We swab up to 30 live individuals per site and subsequently use quantitative real time PCR (polymerase chain reaction) to test for Bsal infections. Like all partners in this project we use the same standard protocols. 

In addition, we run a Bsal hotline (+49 - 651 - 201 4174) for emergency contact in case of observed salamander declines.

Salamander Fungus Research Goes On


The salamander fungus, Batrachochytrium salamandrivorans (Bsal), has been identified as a serious threat to the amphibian diversity of the Western Palearctic. It is suggested that this pathogen is of Asian origin and has been introduced into Europe some years ago, with records so far known from Belgium, Germany and the Netherlands. Apparently, Bsal is spreading in the wild, e.g. the "Eifel" in Germany. We have now developed a first epidemiological model that explores the effects of Bsal on host populations (fire salamander). The model suggests that disease outbreaks can occur at very low host densities so that natural populatiosn are at high risk of severe decline - or extinction. The research was conducted in collaboration with colleagues from Braunschweig and Zurich Universities and with the expertise of Wildlife Analysis GmbH,  Zurich.

Apart from these theoretical efforts, our field-based research and monitoring will continue from 2017 on. We have recently been able to obtain grants by the German Federal Agency for Nature Conservation (Bundesamt für Naturschutz) and the European Commission Directorate-General Environment. 

Schmidt, B.R. C. Bozzuto, S. Lötters & S. Steinfartz (2017): Dynamics of host populations affected by the emerging fungal pathogen Batrachochytrium salamandrivorans. — Royal Society Open Science, 4: 160801.

Dangerous Salamander Fungus Spreads...


For some years now, we have to struggle with a new amphibian pathogen in Europe, the skin-eating salamander fungus, Batrachochytrium salamandrivorans (Bsal). It kills salamanders and newts. Especially the Fire salamander is affected, while frogs and toads seem fine with Bsal. Apparently of Asian origin, there is evidence that Bsal is now emerging in its invasive European range, although this is not proven with certainty yet. Bsal is considered a serious threat to Western Palearctic amphibian diversity. 

Our ongoing research — in collaboration with Biostation Aachen, Biostation Düren, Braunschweig University, Ghent University, RAVON, and others — has yielded 14 of 55 studied sites as Bsal-positive in Belgium, Germany and the Netherlands. In some of these, Bsal was not detected on earlier occasions. Read more in our scientific publication by Spitzen van-der-Sluijs et al. (2016). For updates and most recent Bsal findings, we recommend the webpage of RAVON.

Because of the threat by Bsal and to aid mitigation strategies and conservation action, we for the first time have modelled the potential distribution of this fungus for the region where it is so far recorded in Europe. In this study, we created various models with different data and assumptions. As a novelty, we also incorporated fine-scale weather data, which allowed us to emphasize predictors in accordance with the known pathogen's biology. In this way, we were able to appreciate Bsal's invasion potential in geographic space and to identify areas which are of high invasion risk, such as the Black Forest.

Spitzen-van der Sluijs, A., A. Martel, J. Asselberghs, E.K. Bales, W. Beukema, M.C. Bletz, L. Dalbeck, E. Goverse, A. Kerres, T. Kinet, K. Kirst, A. Laudelout, L.F. Marin da Fonte, A. Nöllert, D. Ohlhoff, J. Sabino-Pinto, B.R. Schmidt, J. Speybroeck, F. Spikmans, S. Steinfartz, M. Veith, M. Vences, N. Wagner, F. Pasmans & S. Lötters (2016): Expanding distribution of lethal amphibian fungus Batrachochytrium salamandrivorans in Europe. — Emerging Infectious Diseases, 22: 1286-1288.


Feldmeier, S., L. Schefczyk, N. Wagner, G. Heinemann, M. Veith & S. Lötters (2016): Present and future high risk zones for the spreading lethal salamander chytrid fungus in its invasive range in Europe using bioclimate and weather extremes. PLoS ONE, 11: e0165682.

Diversification and Niche Conservatism in an African Frog Since the Miocene


The Mascarene ridged frog (Ptychadena mascareniensis species complex) is known from many humid savannas and open forests of mainland Africa, Madagascar, the Seychelles and the Mascarene Islands. In a recent study (Zimkus et al. 2017), by multiple collaborators, we demonstrate high levels of genetic differentiation with ten distinct lineages, and that Central Africa is diversity hotspot for these frogs. Further, we show that most speciation took place throughout the Miocene, including 'Out-of-Africa' overseas dispersal. Interestingly, the bioclimatic niche was remarkably well conserved, with most species tolerating similar temperature and rainfall conditions common to the Central African region. The P. mascareniensis complex provides insights into how bioclimatic niche shaped the current biogeographic patterns with niche conservatism being exhibited by the Central African radiation and niche divergence shaping populations in West Africa and Madagascar.

Zimkus, B.M., L.P. Lawson, M.F. Barej, C.D. Barratt, A. Channing, K.M. Dash, J.M. Dehling, L. Du Preez, P.-S. Gehring, E. Greenbaum, V. Gvoždík, J. Harvey, J. Kielgast, C. Kusamba, Z.T. Nagy, M. Pabijan, J. Penner, M.-O. Rödel, M. Vences & S. Lötters (2017): Leapfrogging into new territory: How Mascarene ridged frogs diversified across Africa and Madagascar to maintain their ecological niche. — Molecular Phylogenetics and Evolution, 106: 254-269.

The DZG "Masterpreis" 2016 Goes to Our Lab


The German Zoological Society DZG (Deutsche Zoologische Gesellschaft) has awarded Sarah S. Bisanz for her MEd thesis in Biology entitled "Aktivitätsräume von Ameerega trivittata im amazonischen Tieflandregenwald in Peru". In her study, Sarah examined the home range behavior of a Neotropical poison frog at Panguana Biological Fieldstation in a lowland rainforest of Amazonian Peru. Ameerega trivittata is one of our focal taxa when studying evoluton and dispersal of Amazonian biota. Life history information is important when trying to understand historical processes.

Sarah's fieldwork was carried out in 2014. We have repeated the same study in the following year. A scientific publication on the combined results has recently been published, reporting site fidelity over consecutive years and for the first time female home range behavior in Ameerega trivittata, so far only known in males of this poison frog species.

Neu, C.P., S.S. Bisanz, J.A. Nothacker, M. Mayer & S. Lötters (2016): Male and female home range behavior in the Neotropical poison frog Ameerega trivittata (Anura, Dendrobatidae) over two consecutive years. — South American Journal of Herpetology, 11: 149-156.