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The stratigraphy and dating of lacustrine sediments and loess derivatives from Rodderberg, a crater of the East Eifel Volcanic Field in Germany, is based on luminescence dating and incorporates radiocarbon ages, fingerprinting of key tephra layers of the East Eifel Volcanic Field (Rieden Tephra, Hüttenberg Tephra, Laacher See Tephra), pollen stratigraphy, varve counting data, and a correlative age–depth model. These methods yield a robust age–depth model for the last 258 ka. Beyond this, luminescence ages differ from tephra‐derived ages. In light of the apparent presence of the Rieden Tephra, the lowermost interglacial is assigned to Marine Isotope Stage (MIS) 11 or 420 ka. This provides a high‐resolution record of environmental conditions representing an analogue for the Holocene, characterized by a warming planet. However, new luminescence ages may indicate a younger age for basal sediments, with the lowermost interglacial representing MIS 9. Both age–depth models constrain regional environmental changes during the Middle Pleistocene controlled by global climate variations. For the hydrologically closed nature of the Rodderberg crater, with limited pathways for sediment inflow and erosional export, these results shed new light on the continuity of long Middle Pleistocene records. [ABSTRACT FROM AUTHOR]

Aim: Aposematic animals, i.e., those that are defended and warn potential predators through signals, are suggested to have resource‐gathering advantages against non‐aposematic ones. We here explore this in a biogeographic framework expecting that aposematic species are better dispersers, which translates into larger geographic range size. Location: South America. Taxon: Poison frogs (Amphibia; Aromobatidae and Dendrobatidae). Methods: We use 43 toxic and 26 non‐toxic poison frog species from the lowlands only as representatives of aposematic and non‐aposematic study organisms, respectively. Realised and potential geographic ranges are calculated using minimum convex polygon and species distribution modelling methods, respectively. Accounting for species body size and phylogeny, we test if both range and aposematism are correlated using linear mixed‐effects models. Results: Aposematic and non‐aposematic species neither differ in realised nor in potential geographic range size. There was no effect on body size. Main Conclusions: The role of aposematism is not yet as clear as suggested and determinants of poison frog range sizes are multifaceted. A more integrative approach is needed using the information on behaviour, predation risk, and reproductive biology to assess the role of aposematism on observed species distributions. Such data are not yet available for most species, neither poison frogs nor other aposematic animals. [ABSTRACT FROM AUTHOR]

Amphibians globally suffer from emerging infectious diseases like chytridiomycosis caused by the continuously spreading chytrid fungi. One is Batrachochytrium salamandrivorans (Bsal) and its disease ‒ the 'salamander plague' ‒ which is lethal to several caudate taxa. Recently introduced into Western Europe, long distance dispersal of Bsal, likely through human mediation, has been reported. Herein we study if Alpine salamanders (Salamandra atra and S. lanzai) are yet affected by the salamander plague in the wild. Members of the genus Salamandra are highly susceptible to Bsal leading to the lethal disease. Moreover, ecological modelling has shown that the Alps and Dinarides, where Alpine salamanders occur, are generally suitable for Bsal. We analysed skin swabs of 818 individuals of Alpine salamanders and syntopic amphibians at 40 sites between 2017 to 2022. Further, we compiled those with published data from 319 individuals from 13 sites concluding that Bsal infections were not detected. Our results suggest that the salamander plague so far is absent from the geographic ranges of Alpine salamanders. That means that there is still a chance to timely implement surveillance strategies. Among others, we recommend prevention measures, citizen science approaches, and ex situ conservation breeding of endemic salamandrid lineages. [ABSTRACT FROM AUTHOR]

Anuran amphibians have intensively been studied to understand Amazonian biodiversity. Improved methods and sampling has revealed that many widespread nominal species in fact are complexes of species with smaller allopatric ranges. Pan-Amazonian anuran species are rather an exception. In a case study using the three-striped poison frog (Anura: Dendrobatidae: Ameerega trivittata), we ask how the pan-Amazonian distribution of this taxon can be explained and hypothesize that dispersal has played a major role. Species delimitation and intraspecific relationships of the study species were examined from novel and existing (GenBank) sequences of the mitochondrial 16S rRNA gene from 108 specimens of 38 localities using maximum likelihood and Bayesian methods. We performed BioGeoBEARS models using a time-calibrated population tree to reconstruct the biogeographic history. Our results support that A. trivittata is a pan-Amazonian species scattered over its geographic range. Being of Late Miocene origin, the species rapidly spread into newly available space and repeatedly dispersed for-and backward, while vicariance played a major role only in the Early Pliocene. We suggest that intrinsic morphological and life history characteristics (adult size, relative reproductive success) make A. trivittata a more successful disperser than other species, so that riverine barriers are more permeable and hamper allopatric speciation. We conclude that there is no universal causality explaining Amazonia biodiversity, because species-specific biological characteristics are key determents of biogeographical histories. Comparatively better dispersal advantages foster larger geographic ranges and can explain pan-Amazonian distributions. [ABSTRACT FROM AUTHOR]