Species- and sex-specific chemical composition from an internal gland-like tissue of an African frog family.

Intraspecific chemical communication in frogs is understudied and the few published cases are limited to externally visible and male-specific breeding glands. Frogs of the family Odontobatrachidae, a West African endemic complex of five morphologically cryptic species, have large, fatty gland-like strands along their lower mandible. We investigated the general anatomy of this gland-like strand and analysed its chemical composition. We found the strand to be present in males and females of all species. The strand varies in markedness, with well-developed strands usually found in reproductively active individuals. The strands are situated under particularly thin skin sections, the vocal sac in male frogs and a respective area in females. Gas-chromatography/mass spectrometry and multivariate analysis revealed that the strands contain sex- and species-specific chemical profiles, which are consistent across geographically distant populations. The profiles varied between reproductive and non-reproductive individuals. These results indicate that the mandibular strands in the Odontobatrachidae comprise a so far overlooked structure (potentially a gland) that most likely plays a role in the mating and/or breeding behaviour of the five Odontobatrachus species. Our results highlight the relevance of multimodal signalling in anurans, and indicate that chemical communication in frogs may not be restricted to sexually dimorphic, apparent skin glands.

The global importance and interplay of colour-based protective and thermoregulatory functions in frogs.

Small-scale studies have shown that colour lightness variation can have important physiological implications in ectotherms, with darker species having greater heating rates, as well as protection against pathogens and photooxidative damage. Using data for 41% (3059) of all known frog and toad species (Anura) from across the world, we reveal ubiquitous and strong clines of decreasing colour lightness towards colder regions and regions with higher pathogen pressure and UVB radiation. The relative importance of pathogen resistance is higher in the tropics and that of thermoregulation is higher in temperate regions. The results suggest that these functions influence colour lightness evolution in anurans and filtered for more similarly coloured species under climatic extremes, while their concurrent importance resulted in high within-assemblage variation in productive regions. Our findings indicate three important functions of colour lightness in anurans - thermoregulation, pathogen and UVB protection - and broaden support for colour lightness-environment relationships in ectotherms.

Drop dead! Female mate avoidance in an explosively breeding frog.

Males' and females' reproductive strategies may differ, potentially leading to sexual conflict. Increased efforts by males (harassment, forced copulation, intimidation) to gain access to females could even negatively affect female survival and thus lead to reproductive failure for both individuals. In anurans, a higher mortality risk of mating females has been reported in explosive breeding species. During these mating events, several males cling to a female, which are mostly unable to get rid of the unwanted males. This can lead to the female's death. From the literature, it seems that females of explosive breeding frogs have no means to reject unwanted males. Here we describe female mate avoidance behaviours in the European common frog. We observed three female avoidance behaviours, namely 'rotation', 'release call(s)' and tonic immobility (death feigning). These behaviours were significantly associated with smaller female body size, and smaller females were more successful in escaping amplexus. Tonic immobility as a tactic to avoid mating or male harassment has only been observed in a handful of species and only in one other amphibian. Our observations show that females in explosive breeding frogs may not be as passive and helpless as previously thought.

Reed bamboos drive skull shape evolution in bush frogs of the Western Ghats, Peninsular India.

Reed bamboo is a major ecological and economic resource for many animals, including humans. Nonetheless, the influence of this plant's evolutionary role on the morphology of animal species remains unexplored. Here, we investigated the significance of bamboo habitats as ecological opportunities in shaping the skull morphology of bush frogs (Raorchestes) from the Western Ghats, Peninsular India. We applied a three-dimensional (3D) geometric morphometric approach to capture the skull shape of 55 species of bush frogs. We visualized the skull shape variables in phylomorphospace with principal component analysis and performed phylogenetic generalized least-squares analysis to assess the impact of cranial size (evolutionary allometry) and habitat (bamboo or non-bamboo) on cranial shape. We quantified the morphological disparity between bamboo and non-bamboo bush frogs' skull shape, and employed RRphylo, a phylogenetic ridge regression method, to access the evolutionary rate and rate shifts of skull shape change. The phylomorphospace delineated bamboo and non-bamboo bush frogs. While cranial shape exhibited a significant but smaller association with size, its association with habitat type was non-significant. We detected, however, significant differences in skull shape between the two frog groups, with bamboo frogs showing higher morphological disparity and a remarkable shift in the evolutionary rate of skull shape diversification. These findings underscore the role of reed bamboo in the evolution of skull shape in the radiation of frogs, endemic to the Western Ghats. We demonstrate that the association between the members of two distinct endemic clades (bamboo reeds and bamboo frogs) is the outcome of a deep-time ecological opportunity that dates back to the Miocene.

Species- and sex-dependent changes in body size between 1892 and 2017, and recent biochemical signatures in rural and urban populations of two ground beetle species.

Increasing urbanisation and intensified agriculture lead to rapid transitions of ecosystems. Species that persist throughout rapid transitions may respond to environmental changes across space and/or time, for instance by altering morphological and/or biochemical traits. We used natural history museum specimens, covering the Anthropocene epoch, to obtain long-term data combined with recent samples. We tested whether rural and urban populations of two ground beetle species, Harpalus affinis and H. rufipes, exhibit spatio-temporal intraspecific differences in body size. On a spatial scale, we tested signatures of nitrogen and carbon stable isotopes enrichments in different tissues and body components in recent populations of both species from urban and agricultural habitats. For body size examinations, we used beetles, collected from the early 20th century until 2017 in the Berlin-Brandenburg region, Germany, where urbanisation and agriculture have intensified throughout the last century. For stable isotope examinations, we used recent beetles from urban and agricultural habitats. Our results revealed no spatio-temporal changes in body size in both species' females. Body size of H. rufipes males decreased in the city but remained constant in rural areas over time. We discuss our findings with respect to habitat quality, urban heat and interspecific differences in activity pattern. Although nitrogen isotope ratios were mostly higher in specimens from agricultural habitats, some urban beetles reached equal enrichments. Carbon signatures of both species did not differ between habitats, detecting no differences in energy sources. Our results indicate that increasing urbanisation and intensified agriculture are influencing species' morphology and/or biochemistry. However, changes may be species- and sex-specific.

The smallest of its kind: Description of a new cryptic Amnirana species (Amphibia, Anura, Ranidae) from West African rainforests.

The distribution of the White-Lipped Frog Amnirana albolabris was long assumed to extend from eastern-central to western African rainforests. However, recent molecular phylogenetic analyses revealed that this taxon likely represents several undescribed species. Because the name-bearing types were collected in Gabon, the distantly related West African populations clearly represent an undescribed species that partly occurs in sympatry with Amnirana fonensis. Based on an integrative taxonomic approach, including molecular, morphological, and acoustic data, we describe the 'albolabris' populations from the Upper Guinean Forest Zone as a new species, and redescribe the morphologically similar A. fonensis on the bases of a larger series of genotyped individuals, including the first known females. We also provide new biological information for A. fonensis, including their advertisement call, habitat, and reproductive data. The new species is sister to A. fonensis and the two species differ by 5.8% in the mitochondrial 16S ribosomal RNA gene. Morphologically, males of the new species are smaller and have relatively smaller humeral glands. Females of the new species seem to have shorter legs than A. fonensis. In comparison to A. fonensis, the advertisement call of the new species has a higher dominant frequency and more pronounced frequency modulation. The two species differ in their distribution and habitat preferences, as revealed by environmental niche modelling. Whereas the new species is restricted to the Upper Guinean forests and thus is a true lowland-rainforest inhabitant, A. fonensis lives predominantly in Guinean montane forests in the forest-savanna mosaic zone.

Savanna vegetation increase triggers freshwater community shifts.

Tropical savannas are globally extensive and ecologically invaluable ecosystems. As most ecosystems however, they are subject to serious anthropogenic stress. Defaunation, and especially the loss of large mammals, is pervasive in tropical savannas and known to trigger wide-ranging ecological effects, from vegetation changes to the loss of ecosystem function. Despite what is currently known about the terrestrial consequences of defaunation, and the potential cross-ecosystem influence of large mammals, virtually no research has investigated associated effects on small adjacent water bodies. This research gap persists because (1) tropical savannas have been historically neglected, (2) the ecological value of small water bodies (e.g. ponds) is only recently being recognized, and (3) empirical baseline data are often lacking. In this paper, we compared a rare pre-change dataset with newly collected data on 213 freshwater assemblages, to investigate community structure and composition before and after a major defaunation event. Our research focused on a diverse species assemblage of amphibian larvae (i.e. tadpoles) in temporary savanna ponds. We found that pond vegetation cover increased from 16.0% to 45.6% post-defaunation, that is, a near three-fold increase. Such habitat changes seemed to have benefitted those species that use vegetation during reproduction (e.g. the leaf-folding Afrixalus spp.), while others have declined. Interestingly, we found a strong correlation between tadpole community shifts and other freshwater organisms, which indicates that habitat changes have affected a wide variety of aquatic organisms. Given that organisms inhabiting temporary aquatic habitats often have complex life histories with terrestrial adult life stages, we propose that the terrestrial effects of defaunation have indirectly led to distinct aquatic communities, in addition to direct habitat effects. These results shed new light on the potential role of large-bodied mammals in shaping adjacent ecosystems, and raise important questions concerning the functioning of temporary aquatic systems in the Anthropocene.

Les savanes tropicales sont des écosystèmes étendus à l'échelle mondiale et d'une valeur écologique inestimable, mais qui sont soumis à une pression anthropique croissante. La défaunation, en particulier la perte de grands mammifères, est omniprésente dans les savanes tropicales et pouvant déclencher des effets écologiques de grande envergure allant des changements de végétation à la perte des fonctions écosystémiques. Malgré ce qui est connu des conséquences terrestres de la défaunation, presque aucune recherche n'a étudié les effets de la défaunation sur les plans d'eau temporaires adjacents qui sont utilisés par les grands mammifères. Cette lacune persiste parce que (1) les savanes tropicales ont été historiquement négligées, (2) la valeur écologique des plans d'eau temporaires a souvent été sous-estimée et (3) les données empiriques de référence sont souvent absentes. Dans l'étude présente, nous avons utilisé des données pré/post-défaunation sur 213 assemblages aquatiques de savane, dans le but d'étudier la structure et la composition de ces communités avant et après qu'un événement majeur de défaunation ait eu lieu. Notre recherche se focalise sur des plans d'eau temporaire comptant un nombre important d'espèces de larves d'amphibiens (têtards). Nous avons détecté une multiplication moyenne par près de trois de la couverture végétale des plans d'eau après la défaunation (16,0% à 45,6%). Ces changements d'habitat semblent avoir profité aux espèces qui utilisent la végétation pour leur reproduction (par exemple, Afrixalus spp.), tandis que d'autres espèces avec d'autres préférences d'habitat ont décliné. Nous avons calculé une forte corrélation entre la composition des têtards et celle de leurs prédateurs, ce qui indique que les changements d'habitat ont affecté la plupart des membres de ces communautés aquatiques. Étant donné que les organismes d'habitats aquatiques temporaires ont pour la plupart un cycle biologique complexe figurant à la fois un stade larvaire aquatique et un stade adulte terrestre, nous proposons qu'en plus des effets directs sur l'habitat aquatique (augmentation de la végétation), les effets terrestres de la défaunation ont indirectement altéré les communautés. Ces résultats suggèrent un rôle important des grands mammifères par leur influence sur les écosystèmes aquatique adjacents et soulèvent des questions urgentes concernant la fonctionnalité des systèmes aquatiques temporaires dans l'Anthropocène.

A global reptile assessment highlights shared conservation needs of tetrapods.

Comprehensive assessments of species' extinction risks have documented the extinction crisis1 and underpinned strategies for reducing those risks2. Global assessments reveal that, among tetrapods, 40.7% of amphibians, 25.4% of mammals and 13.6% of birds are threatened with extinction3. Because global assessments have been lacking, reptiles have been omitted from conservation-prioritization analyses that encompass other tetrapods4-7. Reptiles are unusually diverse in arid regions, suggesting that they may have different conservation needs6. Here we provide a comprehensive extinction-risk assessment of reptiles and show that at least 1,829 out of 10,196 species (21.1%) are threatened-confirming a previous extrapolation8 and representing 15.6 billion years of phylogenetic diversity. Reptiles are threatened by the same major factors that threaten other tetrapods-agriculture, logging, urban development and invasive species-although the threat posed by climate change remains uncertain. Reptiles inhabiting forests, where these threats are strongest, are more threatened than those in arid habitats, contrary to our prediction. Birds, mammals and amphibians are unexpectedly good surrogates for the conservation of reptiles, although threatened reptiles with the smallest ranges tend to be isolated from other threatened tetrapods. Although some reptiles-including most species of crocodiles and turtles-require urgent, targeted action to prevent extinctions, efforts to protect other tetrapods, such as habitat preservation and control of trade and invasive species, will probably also benefit many reptiles.

Batrachochytrium salamandrivorans' Amphibian Host Species and Invasion Range.

Batrachochytrium salamandrivorans (Bsal), a species related to the destructive pathogen Batrachochytrium dendrobatidis (Bd), was found and identified in Europe in 2013. Now, a decade later, a large amount of information is available. This includes data from studies in the field, reports of infection in captive amphibians, laboratory studies testing host susceptibility, and data from prospective studies that test for Bsal's presence in a location. We conducted a systematic review of the published literature and compiled a dataset of Bsal tests. We identified 67 species that have been reported positive for Bsal, 20 of which have a threatened conservation status. The distribution of species that have been found with infection encompasses 69 countries, highlighting the potential threat that Bsal poses. We point out where surveillance to detect Bsal have taken place and highlight areas that have not been well monitored. The large number of host species belonging to the families Plethodontidae and Salamandridae suggests a taxonomic pattern of susceptibility. Our results provide insight into the risk posed by Bsal and identifies vulnerable species and areas where surveillance is needed to fill existing knowledge gaps.

Giant Tree Frog diversification in West and Central Africa: Isolation by physical barriers, climate, and reproductive traits.

Secondary sympatry amongst sister lineages is strongly associated with genetic and ecological divergence. This pattern suggests that for closely related species to coexist in secondary sympatry, they must accumulate differences in traits that mediate ecological and/or reproductive isolation. Here, we characterized inter- and intraspecific divergence in three giant tree frog species whose distributions stretch across West and Central Africa. Using genome-wide single-nucleotide polymorphism data, we demonstrated that species-level divergence coincides temporally and geographically with a period of large-scale forest fragmentation during the late Pliocene. Our environmental niche models further supported a dynamic history of climatic suitability and stability, and indicated that all three species occupy distinct environmental niches. We found modest morphological differentiation amongst the species with significant divergence in tympanum diameter and male advertisement call. In addition, we confirmed that two species occur in secondary sympatry in Central Africa but found no evidence of hybridization. These patterns support the hypothesis that cycles of genetic exchange and isolation across West and Central Africa have contributed to globally significant biodiversity. Furthermore, divergence in both ecology and reproductive traits appear to have played important roles in maintaining distinct lineages. At the intraspecific level, we found that climatic refugia, precipitation gradients, marine incursions, and potentially riverine barriers generated phylogeographic structure throughout the Pleistocene and into the Holocene. Further studies examining phenotypic divergence and secondary contact amongst these geographically structured populations may demonstrate how smaller scale and more recent biogeographic barriers contribute to regional diversification.

La sympatrie secondaire parmi les espèces sœurs est fortement associée à la divergence génétique et écologique. Ce modèle suggère que pour que des espèces étroitement liées coexistent en sympatrie secondaire, elles doivent accumuler des différences dans les traits qui contribuent à l'isolement écologique ou reproductif. Ici, nous avons caractérisé la divergence inter- et intra-spécifique chez trois espèces de grenouilles arboricoles géantes dont les distributions s'étendent à travers l'Afrique de l'Ouest et Centrale. Avec des données génétiques, nous avons démontré que la divergence au niveau des espèces coïncide temporellement et géographiquement avec une période de fragmentation forestière à la fin du Pliocène. Nos modèles de niches environnementales ont soutenu une histoire dynamique de stabilité climatique, et ont indiqué que les trois espèces occupent des niches environnementales distinctes. Nous avons trouvé une différenciation morphologique modeste parmi les trois espèces mais une divergence significative dans le diamètre du tympan et les cris des mâles. De plus, nous avons confirmé que deux espèces sont présentes en sympatrie secondaire en Afrique Centrale mais n'avons trouvé aucune preuve d'hybridation. Ces résultats soutiennent l'hypothèse que les cycles d'échange génétique et d'isolement à travers l'Afrique de l'Ouest et Centrale ont contribué à une profonde concentration de biodiversité dans la région. De plus, la divergence des traits écologiques et reproducteurs semble avoir joué un rôle important dans le maintien de lignées distinctes. Au niveau intra-spécifique, nous avons constaté que les refuges climatiques, les gradients de précipitation, les incursions marines et potentiellement les barrières fluviales ont généré une structure phylogéographique pendant le Pléistocène et jusqu'à l'Holocène. Des études examinant la divergence phénotypique et le contact secondaire entre ces populations géographiquement structurées pourraient démontrer comment des barrières biogéographiques à échelle plus petite et plus récentes contribuent à la diversification régionale.

Citizen science and online data: Opportunities and challenges for snake ecology and action against snakebite.

The secretive behavior and life history of snakes makes studying their biology, distribution, and the epidemiology of venomous snakebite challenging. One of the most useful, most versatile, and easiest to collect types of biological data are photographs, particularly those that are connected with geographic location and date-time metadata. Photos verify occurrence records, provide data on phenotypes and ecology, and are often used to illustrate new species descriptions, field guides and identification keys, as well as in training humans and computer vision algorithms to identify snakes. We scoured eleven online and two offline sources of snake photos in an attempt to collect as many photos of as many snake species as possible, and attempt to explain some of the inter-species variation in photograph quantity among global regions and taxonomic groups, and with regard to medical importance, human population density, and range size. We collected a total of 725,565 photos-between 1 and 48,696 photos of 3098 of the world's 3879 snake species (79.9%), leaving 781 "most wanted" species with no photos (20.1% of all currently-described species as of the December 2020 release of The Reptile Database). We provide a list of most wanted species sortable by family, continent, authority, and medical importance, and encourage snake photographers worldwide to submit photos and associated metadata, particularly of "missing" species, to the most permanent and useful online archives: The Reptile Database, iNaturalist, and HerpMapper.

Rivers, not refugia, drove diversification in arboreal, sub-Saharan African snakes.

The relative roles of rivers versus refugia in shaping the high levels of species diversity in tropical rainforests have been widely debated for decades. Only recently has it become possible to take an integrative approach to test predictions derived from these hypotheses using genomic sequencing and paleo-species distribution modeling. Herein, we tested the predictions of the classic river, refuge, and river-refuge hypotheses on diversification in the arboreal sub-Saharan African snake genus Toxicodryas. We used dated phylogeographic inferences, population clustering analyses, demographic model selection, and paleo-distribution modeling to conduct a phylogenomic and historical demographic analysis of this genus. Our results revealed significant population genetic structure within both Toxicodryas species, corresponding geographically to river barriers and divergence times from the mid-Miocene to Pliocene. Our demographic analyses supported the interpretation that rivers are indications of strong barriers to gene flow among populations since their divergence. Additionally, we found no support for a major contraction of suitable habitat during the last glacial maximum, allowing us to reject both the refuge and river-refuge hypotheses in favor of the river-barrier hypothesis. Based on conservative interpretations of our species delimitation analyses with the Sanger and ddRAD data sets, two new cryptic species are identified from east-central Africa. This study highlights the complexity of diversification dynamics in the African tropics and the advantages of integrative approaches to studying speciation in tropical regions.

A new critically endangered slippery frog (Amphibia, Conrauidae, Conraua) from the Atewa Range, central Ghana.

Forty-nine years after the last description of a slippery frog, we describe a seventh species of the genus Conraua. The new Conraua is endemic to the Atewa Range Forest Reserve, central Ghana, and is described based on genetic, bioacoustics, and morphological evidence. Recent molecular phylogenetic and species delimitation analyses support this population as distinct from nominotypical C. derooi in eastern Ghana and adjacent Togo. The new species is sister to C. derooi, from which it differs ~4% in the DNA sequence for mitochondrial ribosomal 16S. Genetic divergences in 16S to other species of Conraua range from 412%. The new species is distinguished morphologically from its congeners, including C. derooi, by the combination of the following characters: medium body size, robust limbs, lateral dermal fringing along edges of fingers, cream ventral color with brown mottling, the presence of a lateral line system, indistinct tympanum, the presence of inner, outer, and middle palmar tubercles, and two subarticular tubercles on fingers III and IV. We compare the advertisement calls of the new species with the calls from C. derooi and find that they differ by duration, frequency modulation, and dominant frequency. We discuss two potential drivers of speciation between C. derooi and the new species, including river barriers and fragmentation of previously more widespread forests in West Africa. Finally, we highlight the importance of the Atewa Range Forest Reserve as a critical conservation area within the Upper Guinean biodiversity hotspot.

Successful application of ancient DNA extraction and library construction protocols to museum wet collection specimens.

Millions of scientific specimens are housed in museum collections, a large part of which are fluid preserved. The use of formaldehyde as fixative and subsequent storage in ethanol is especially common in ichthyology and herpetology. This type of preservation damages DNA and reduces the chance of successful retrieval of genetic data. We applied ancient DNA extraction and single stranded library construction protocols to a variety of vertebrate samples obtained from wet collections and of different ages. Our results show that almost all samples tested yielded endogenous DNA. Archival DNA extraction was successful across different tissue types as well as using small amounts of tissue. Conversion of archival DNA fragments into single-stranded libraries resulted in usable data even for samples with initially undetectable DNA amounts. Subsequent target capture approaches for mitochondrial DNA using homemade baits on a subset of 30 samples resulted in almost complete mitochondrial genome sequences in several instances. Thus, application of ancient DNA methodology makes wet collection specimens, including type material as well as rare, old or extinct species, accessible for genetic and genomic analyses. Our results, accompanied by detailed step-by-step protocols, are a large step forward to open the DNA archive of museum wet collections for scientific studies.

Parallel diversification of the African tree toad genus Nectophryne (Bufonidae).

African amphibian diversity remains underestimated with many cryptic lineages awaiting formal description. An important hotspot of amphibian diversification is the Guineo-Congolian rainforest in Central Africa, its richness attributable to present day and ancestral range fragmentation through geological barriers, habitat expansion and contraction, and the presence of steep ecological gradients. The charismatic Nectophryne tree toads present an interesting case study for diversification in this region. The two formally described species comprising this genus show nearly identical geographic distributions extending across most of the Guineo-Congolian rainforest, but show little morphological disparity. Both species harbour extensive genetic diversity warranting taxonomic revisions, and interestingly, when comparing the subclades within each, the two species show remarkably parallel diversification histories, both in terms of timing of phylogenetic splits and their geographic distributions. This indicates that common processes may have shaped the evolutionary history of these lineages.

Night stalkers from above: A monograph of Toxicodryas/ tree snakes (Squamata: Colubridae) with descriptions of two new cryptic species from Central Africa.

The genus Toxicodryas, historically included with the renowned Australasian cat-eyed snakes of the colubrid genus Boiga, currently includes two widespread species (T. blandingii and T. pulverulenta) in western, central, and eastern Africa. We leverage findings from a recent phylogenomic and historical demographic analysis of this genus (based on 2848-4471 Rad-seq loci from across the genome), with robust sampling from throughout the ranges of both species, to define two additional taxonomic units, with species boundaries corresponding to river barriers. Additional morphometric data from scores of examined museum specimens and literature records bolster the recognition of these two new cryptic species. We hypothesize that T. blandingii occurs west of the confluence of the Congo and Ubangi rivers, whereas a cryptic new species that is found east of this biogeographic barrier has significantly higher numbers of ventral scale counts in both sexes, additional significant differences in several scale counts, and lower venom toxicity. Toxicodryas pulverulenta occurs west of the Niger Delta in West Africa, whereas a cryptic new species that is found east of this biogeographic barrier has significantly higher numbers of subcaudal scale counts in both sexes. A review of published information regarding morphological variation, ecology, natural history, habitat, and venom is summarized for these four Toxicodryas species.

Mitogenome analyses elucidate the evolutionary relationships of a probable Eocene wet tropics relic in the xerophile lizard genus Acanthodactylus.

Climate has a large impact on diversity and evolution of the world's biota. The Eocene-Oligocene transition from tropical climate to cooler, drier environments was accompanied by global species turnover. A large number of Old World lacertid lizard lineages have diversified after the Eocene-Oligocene boundary. One of the most speciose reptile genera in the arid Palearctic, Acanthodactylus, contains two sub-Saharan species with unresolved phylogenetic relationship and unknown climatic preferences. We here aim to understand how and when adaptation to arid conditions occurred in Acanthodactylus and when tropical habitats where entered. Using whole mitogenomes from fresh and archival DNA and published sequences we recovered a well-supported Acanthodactylus phylogeny and underpinned the timing of diversification with environmental niche analyses of the sub-Saharan species A. guineensis and A. boueti in comparison to all arid Acanthodactylus. We found that A. guineensis represents an old lineage that splits from a basal node in the Western clade, and A. boueti is a derived lineage and probably not its sister. Their long branches characterize them-and especially A. guineensis-as lineages that may have persisted for a long time without further diversification or have undergone multiple extinctions. Environmental niche models verified the occurrence of A. guineensis and A. boueti in hot humid environments different from the other 42 arid Acanthodactylus species. While A. guineensis probably remained in tropical habitat from periods prior to the Eocene-Oligocene boundary, A. boueti entered tropical environments independently at a later period. Our results provide an important baseline for studying adaptation and the transition from humid to arid environments in Lacertidae.

Citizen science and online data: opportunities and challenges for snake ecology and action against snakebite

The secretive behavior and life history of snakes makes studying their biology, distribution, and the epidemiology of venomous snakebite challenging. One of the most useful, most versatile, and easiest to collect types of biological data are photographs, particularly those that are connected with geographic location and date-time metadata. Photos verify occurrence records, provide data on phenotypes and ecology, and are often used to illustrate new species descriptions, field guides and identification keys, as well as in training humans and computer vision algorithms to identify snakes. We scoured eleven online and two offline sources of snake photos in an attempt to collect as many photos of as many snake species as possible, and attempt to explain some of the inter-species variation in photograph quantity among global regions and taxonomic groups, and with regard to medical importance, human population density, and range size. We collected a total of 725,565 photos—between 1 and 48,696 photos of 3098 of the world's 3879 snake species (79.9%), leaving 781 “most wanted” species with no photos (20.1% of all currently-described species as of the December 2020 release of The Reptile Database). We provide a list of most wanted species sortable by family, continent, authority, and medical importance, and encourage snake photographers worldwide to submit photos and associated metadata, particularly of “missing” species, to the most permanent and useful online archives: The Reptile Database, iNaturalist, and HerpMapper.

Tracking Batrachochytrium dendrobatidis Infection Across the Globe.

Infection records of Batrachochytrium dendrobatidis (Bd), a pathogen that has devastated amphibian populations worldwide, have rapidly increased since the pathogen's discovery. Dealing with so many records makes it difficult to (a) know where, when and in which species infections have been detected, (b) understand how widespread and pervasive Bd is and (c) prioritize study and management areas. We conducted a systematic review of papers and compiled a database with Bd infection records. Our dataset covers 71 amphibian families and 119 countries. The data revealed how widespread and adaptable Bd is, being able to infect over 50% of all tested amphibian species, with over 1000 confirmed host species and being present in 86 countries. The distribution of infected species is uneven among and within countries. Areas where the distributions of many infected species overlap are readily visible; these are regions where Bd likely develops well. Conversely, areas where the distributions of species that tested negative overlap, such as the Atlantic Coast in the USA, suggest the presence of Bd refuges. Finally, we report how the number of tested and infected species has changed through time, and provide a list of oldest detection records per country.

Superfrogs in the city: 150 year impact of urbanization and agriculture on the European Common Frog.

Despite growing pressure on biodiversity deriving from increasing anthropogenic disturbances, some species successfully persist in altered ecosystems. However, these species' characteristics and thresholds, as well as the environmental frame behind that process are usually unknown. We collected data on body size, fluctuating asymmetry (FA), as well as nitrogen stable isotopes (δ15 N) from museum specimens of the European Common Frog, Rana temporaria, all originating from the Berlin-Brandenburg area, Germany, in order to test: (a) if specimens have changed over the last 150 years (1868-2018); and (b) if changes could be attributed to increasing urbanization and agricultural intensity. We detected that after the Second World War, frogs were larger than in pre-war Berlin. In rural Brandenburg, we observed no such size change. FA analysis revealed a similar tendency with lower levels in Berlin after the war and higher levels in Brandenburg. Enrichment of δ15 N decreased over time in both regions but was generally higher and less variable in sites with agricultural land use. Frogs thus seem to encounter favorable habitat conditions after pollution in postwar Berlin improved, but no such tendencies were observable in the predominantly agricultural landscape of Brandenburg. Urbanization, characterized by the proportion of built-up area, was not the main associated factor for the observed trait changes. However, we detected a relationship with the amount of urban greenspace. Our study exemplifies that increasing urbanization must not necessarily worsen conditions for species living in urban habitats. The Berlin example demonstrates that public parks and other urban greenspaces have the potential to serve as suitable refuges for some species. These findings underline the urgency of establishing, maintaining, and connecting such habitats, and generally consider their importance for future urban planning.