Amphibians of Lublin

The study was conducted in 2016-2017 in the Podkielecki Landscape Protection Area (area 26,485 ha). It was focused on the occurrence and distribution of amphibians and reptiles, the biology of the selected species and the existing threats. Established in 1995, the Podkielecki Landscape Protection Area surrounds the city of Kielce from the north, east and south-east, and adjoins several other protected areas. It covers the western part of the Świętokrzyskie Mountains (part of the Klonowskie and Masłowskie ranges) and the southern part of the Suchedniów Plateau. The studied area is mostly covered by forest and thicket communities (48.1%) and farmlands (39.9%), followed by built-up areas (7.8%), industrial areas (0.5%), roads and railways (2.7%), and surface water bodies (1%). The protected area is developed mainly on Palaeozoic rocks, including Cambrian and Ordovician sandstones, Silurian and Carboniferous shales, and Devonian marls. Podzolic soils predominate among soils. The largest rivers include Lubrzanka, Czarna Nida, Bobrza and Belnianka. There are no natural lakes within the PLPA limits, and the largest artificial reservoirs include the Cedzyna Reservoir, Morawica Reservoir, Suków Sandpit and two sedimentation reservoirs of the Kielce Power Plant. The area includes 2 nature reserves: Barcza and Sufraganiec. The following amphibian species were recognised during the investigations within the borders of the studied area: alpine newt Ichthyosaura alpestris Laur., great crested newt Triturus cristatus Laur., smooth newt Lissotriton vulgaris L., European fire-bellied toad Bombina bombina L., common spadefoot toad Pelobates fuscus Laur., common toad Bufo bufo L., natterjack toad Epidalea calamita Laur., European green toad Bufotes viridis Laur., European tree frog Hyla arborea L., pool frog Pelophylax lessonae Cam., edible frog Pelophylax esculentus L., marsh frog Pelophylax ridibundus Pall., moor frog Rana arvalis Nilss., and common frog Rana temporaria L. The reptiles were represented by sand lizard Lacerta agilis L., viviparous lizard Zootoca vivipara Jacquin, slow worm Anguis fragilis L., grass snake Natrix natrix L. and common European adder Vipera berus L. The study also included the phenology and breeding biology of the common toad and common frog. The most crucial herpetofauna conservation problems identified here include amphibians killed on roads by vehicles. The study area is intersected by very busy roads, in particular: European route no. E77, national roads nos. 73, 74 and S74, and regional roads nos. 745, 750 and 764. For this reason, future road reconstruction projects should consider the assembly of various crossing roads for wildlife, particularly on the 600 m long section of national road no. 74 near Cedzyna Reservoir. Other threats include illegal waste dumping, pollution of surface waters, fire setting, overgrowing and desiccation of small water bodies. © IOŚ-PIB

- Acid rain for many decades has led to severe acidification of waters in southern Norway. Acidic water can be fatal to gill-breathing vertebrates (i.e. fish and larval amphibians). Great crested newt Triturus cristatus (GCN) - seems to be less tolerant of acidic water than other Norwegian amphibians. Not until 2015 was GCN recorded in Agder, the southernmost county in Norway, when the larvae of this species were found in two ponds. The aim of our investigation, in late spring and summer 2021, was to find out whether GCN was still present in these two ponds and ten others in the same area, which are surrounded by peat bogs and forest. Since this is a marginal and acidic area with probably low numbers of individuals and low detectability, we used three survey methods in combination (funnel traps, nets, and eDNA) and also measured water conductivity and pH. At the same time, the occurrence of other amphibians in the area were investigated; the smooth newt Lissotriton vulgaris, the common toad Bufo bufo, the common frog Rana temporaria and the moor frog Rana arvalis. Using traps and nets, GCN was found in four ponds but in only two of these ponds by eDNA. However, GCN eDNA was detected in three other ponds, showing that a combination of methods gave the most complete result. eDNA of the common toad and the common frog were detected in (almost) all samples but there were few records from traps or nets. Smooth newts were detected in almost all ponds by traps, nets and eDNA, while none of the methods detected the moor frog. Especially when a species is rare at a location, eDNA analysis may be the most efficient method of detection. However, only trapping and netting can give information about breeding. Water pH in late spring and early summer varied from 4.7 to 5.6 (median pH 5.1), which makes this area marginal for amphibian reproduction.

Alpine areas are extreme habitats that require special adaptations and involve major trade-offs in terms of life history. Amphibians have the ability to adapt both their life history and developmental traits to alpine environments. Temperate amphibians depend on the quality and availability of aquatic habitats for reproduction. We explored the aquatic habitat used by amphibians in the alpine area of Retezat Mountains, Southern Carpathians, Romania. We surveyed 40 aquatic habitats in a 380 ha area delimited by mountain crests and drained by a steep valley. Each aquatic habitat was characterized using 10 environmental variables. Only three amphibian species occur at elevations above 1900 m, the most widespread being the Common Frog Rana temporaria. The Common Frog showed preference for breeding aquatic habitats, the variables of importance being altitude, solar radiation, water chemistry and grazing. Higher elevation and lower solar radiation decreased frog occurrence, while the impact of grazing favored the use of water bodies. Acidification is eminent in the area with pH dropping below 5 in 20% of the water bodies. Overall, amphibian occurrence in alpine area can be partly explained by the characteristics of aquatic habitats.

Timing of parental breeding shapes sensitivity to nitrate pollution in the common frog Rana temporaria

The research was conducted in 2016–2017 in the 6,613-ha Kozubów Landscape Park (KLP). It focused on the occurrence and distribution of amphibians and reptiles, the biology and phenology of selected species and the existing threats. The KLP, established in 1986, is located in the Nida Basin, covering the eastern part of the Wodzisławski Ridge. This area is characterised by diverse landscape features formed on a chalk substrate. A significant part of the KLP (48.8%) is covered by forests growing on the tops and slopes of loess hills intersected by valleys and gorges. Hornbeam forests and fragments of riparian forests have retained a semi-natural character. The steep, non-forested slopes with a southern and south-western exposure are overgrown by thermophilic xerothermic grasslands. Xerothermic plant communities show a relatively low species diversity, because the main type of substrate in this area is loess. Two nature reserves, Polana Polichno and Wroni Dół, are located within the KLP borders. The following amphibian species were found in the KLP: smooth newt (Lissotriton vulgaris L.), great crested newt (Triturus cristatus Laur.), European fire-bellied toad (Bombina bombina L.), common spadefoot toad (Pelobates fuscus Laur.), common toad (Bufo bufo L.), European green toad (Bufotes viridis Laur.), European tree frog (Hyla arborea L.), edible frog (Pelophylax esculentus L.), pool frog (Pelophylax lessonae Cam.), moor frog (Rana arvalis Nilss.) and common frog (Rana temporaria L.). Reptiles are represented by the sand lizard (Lacerta agilis L.), viviparous lizard (Zootoca vivipara Jacquin), slow worm (Anguis fragilis L.), grass snake (Natrix natrix L.), smooth snake (Coronella austriaca Laur.) and common European adder (Vipera berus L.). The study also included the phenology and reproductive biology of common toad and common frog. Major threats to the herpetofauna are posed by grass burning. Unfavourable changes include decreasing water levels and drying out of water bodies.

Genome size variation in the common frog (Rana temporaria) was investigated with flow cytometry in three latitudinally separated populations in Sweden to see whether it could provide a useful tool for sex-identification in this species. Depending on the sex and population, per cell DNA content (2C value) varied from 8.823 to 11.266 pg with a mean (+/- SE) 2C value of 9.961+/-0.083 pg. Analysis of variance revealed significant differences in genome size among populations and between sexes. Females had ca 3% larger genomes (x=10.133+/-0.068 pg) than males (x=9.832+/-0.068 pg) in all of the populations (sex x population interaction: P>0.10). Individuals from the southern-most population had significantly (x=9.330+/-0.081 pg) smaller genomes than those from the more northern populations (x=10.032+/-0.085 and x=10.584+/-0.085 pg, respectively). These results are in line with the interpretation that males in the common frog are the heterogametic sex, and that there exists large (up to 12%) geographic variation in genome size in this species. However, the sex differences in the genome size are too small to be useful in individual sex identification.

Background. Study of amphibian fauna as a necessary component of ecosystems is always relevant and requires a regular renewal of information, especially in protected areas. We conducted a field investigation of amphibians, a literature review and an inventory of the collections of herpetological funds in relation to three protected areas: the Roztochia Biosphere Reserve, the Yavorivskyi National Park, and the Cholgini Ornithological Reserve. Materials and Methods. The field study was performed by classical methods: route method with manual catching and with herpetological nets, vocalization method, sampling of amphibians crushed on the road, and catching individuals with frog fences. We also analyzed the literature and amphibian collections in the Zoological Museum of Ivan Franko National University of Lviv. Results. According to the available literature, the amphibian fauna of these three areas under protection is similar and typical of this region. The results of our field research slightly differ from the literature data, thus, there is a need for further studies. On the study areas, we found 12 species of amphibians, which is more than half of the number of amphibian species in Ukraine, in particular: Smooth Newt Lissotriton vulgaris, Great Cres­ted Newt Triturus cristatus, Fire-bellied Toad Bombina bombina, Eastern Tree Frog Hyla orientalis, Common Spadefoot Toad Pelobates fuscus, Common Toad Bufo bufo, Green Toad Bufotes viridis, Common Frog Rana temporaria, Moor Frog Rana arvalis, Marsh Frog Pelophylax ridibundus, Edible Frog Pelophylax esculentus and Pool Frog Pelophylax lessonae. We detected 2 species of Caudata and 10 species of Anura. 10 species of amphibians were found in the Roztochia Biosphere Reserve, 5 species – in the Yavorivskyi National Park, and 9 species – in the Cholgini Ornithological Reserve. Conclusions. According to the field results, 4 species inhabit all three protected areas – Common Toad, Eastern Tree Frog, Marsh Frog and Edible Frog. A relatively small variety of amphibians found in the Yavorivskyi National Park can be due to the homogeneity of habitats and a proximity of one of the largest military proving grounds in Europe, which limits amphibians in choice of the reproductive and trophic habitats. These habitats deserve special attention because of their fast degradation for the last 10 years. Keywords: amphibians, fauna, protected areas, Ukrainian Roztochia, the Roztochia Biosphere Reserve, the Yavorivskyi National Park, the Cholgini Ornithological Reserve

Unpredictable environments are expected to select for adaptive plasticity in traits enabling adjustment of phenotype to prevailing environmental conditions. Common frogs (Rana temporaria) breed frequently in ponds, which dry up before the aquatic larvae have metamorphosed, and consequently, plasticity in timing of metamorphosis in response to pond drying could be adaptive. We investigated the responses of half- and full-sib R. temporaria larvae to simulated pond drying in a factorial experiment to test whether there is adaptive phenotypic plasticity in timing of metamorphosis, and whether this plasticity is genetically determined. As expected under the adaptive hypothesis, we found that larvae exposed to the decreasing water treatment metamorphosed significantly faster than their sibs in the constant water treatments. Furthermore, age and size at metamorphosis were positively correlated in the constant water treatments, but negatively correlated in the decreasing water treatment. However, larvae from decreasing water treatment metamorphosed, on average, at a smaller size as compared to larvae from the constant water treatments, even after controlling for variation in developmental time. Since smaller size at metamorphosis is likely to be related to reduced fitness, this indicates that faster development may trade off with other components of fitness. The results further show that the amount of food received during the four first days of development influenced age and size at metamorphosis, reinforcing the view that early life nutrition may have a significant impact on later life fitness. Although there was a genetic component to developmental rates, we found no evidence for genetic variation in plasticity. In accordance with evidence from other studies, our results suggest existence of adaptive phenotypic plasticity in amphibian development.

B-chromosome and V-shaped spot asymmetry in the common frog (Rana temporaria L.) populations

Decline of the common frog (Rana temporaria) in Luxembourg over the period 2010-2023. In Luxembourg, the common frog Rana temporaria (Linnaeus, 1758) is a species for which the Government is committed to reversing negative population trends by 2030. Monitoring efforts carried out in 246 ponds scattered across the country have enabled a quantitative assessment of their breeding population trends. A presence survey and a count of the number of clutches were conducted in March between 2010 and 2012 and again between 2021 and 2023. A comparative analysis of the two sampling periods reveals a significant decline of 39% in the number of occupied ponds and 38% in the number of clutches at the sampled ponds. Several land-cover variables were extracted at different spatial scales around the sampled ponds (in a radius of 100, 400 and 1000 meters). Our analyses indicated that low numbers of clutches were associated with arable land around ponds. It also showed that the number of common frog clutches remained stable or increased in ponds surrounded by large areas of forest and flood plains, whereas it decreased in ponds where there were fish. To reverse the decline of the common frog, the creation of new ponds near woodland is essential, but the management and restoration of the terrestrial habitat around wetlands is also important, especially in agricultural areas. The conservation of the common frog must be carried out not only locally, but also at the landscape level, in order to account for the connectivity and exchanges between populations.

Decline of the common frog (Rana temporaria) in Luxembourg over the period 2010-2023. In Luxembourg, the common frog Rana temporaria (Linnaeus, 1758) is a species for which the Government is committed to reversing negative population trends by 2030. Monitoring efforts carried out in 246 ponds scattered across the country have enabled a quantitative assessment of their breeding population trends. A presence survey and a count of the number of clutches were conducted in March between 2010 and 2012 and again between 2021 and 2023. A comparative analysis of the two sampling periods reveals a significant decline of 39% in the number of occupied ponds and 38% in the number of clutches at the sampled ponds. Several land-cover variables were extracted at different spatial scales around the sampled ponds (in a radius of 100, 400 and 1000 meters). Our analyses indicated that low numbers of clutches were associated with arable land around ponds. It also showed that the number of common frog clutches remained stable or increased in ponds surrounded by large areas of forest and flood plains, whereas it decreased in ponds where there were fish. To reverse the decline of the common frog, the creation of new ponds near woodland is essential, but the management and restoration of the terrestrial habitat around wetlands is also important, especially in agricultural areas. The conservation of the common frog must be carried out not only locally, but also at the landscape level, in order to account for the connectivity and exchanges between populations.

Polycyclic Aromatic Hydrocarbons (PAHs) are damaging for aquatic organisms such as amphibians. In this study, toxicity of a mixture of three PAHs (naphthalene (2 rings), phenanthrene (3 rings) and pyrene (4 rings)) was tested on Common frog (Rana temporaria) embryos. The protective role of the jelly coat surrounding the eggs was studied by exposing embryos with and without jelly coat to PAHs dissolved in an aqueous solution without organic solvent. Results showed that the mixture of these three PAHs significantly increase embryonic mortality rate after a few hours of exposure. Embryos with jelly coat tend to suffer a lower mortality rate than embryos without jelly. The jelly surrounding eggs is filled by water of the breeding site, which can contain pollutants. Because jelly characteristics vary among species, sensitivity to environmental pollutants and levels of embryonic protection could be different among amphibian species.

From 2005 to 2007 the water bodies in the area of Gniezno have been controlled to establish amphibian species composition and their number. Thirty four of water bodies were under observation. In 23 among them (67.6%) the following species of amphibians were present: common frog Rana temporaria, moor frog Rana arvalis, “water frogs” Rana esculenta complex, common spadefoot, fire-bellied toad Bom- bina bombina, common toad Bufo bufo; green toad Bufo viridis; and smooth newt Tritunis vulgaris. “Water frogs” and common frog formed the largest populations. Great crested newt Tritunis cristatus, natterjack toad Bufo calamita, and tree frog Hyla arborea were not observed.

Global biodiversity is experiencing a worrying decline. Habitats destruction, associated to their degradation and fragmentation are among the greatest causes. Amphibians are particularly interesting because they are more threatened and decline more rapidly than either birds or mammals. In this context, the objective of our research is to improve some methodological approaches and offer practical scientific bases for decision making in landscape management and amphibian conservation. Our study focuses on fragmented Swiss landscapes. We developed a method that uses land-cover data and expert knowledge to enable a spatially explicit assessment of 1) the temporal changes in the nature conservation value of the landscape and 2) the rehabilitation potential of the landscape. We applied this Geographical Information Systems (GIS) based approach in the Swiss Rhone plain and we used the years 1900 as the reference state. The method constitutes a helpful tool for communication, decision-making and biological conservation management in landscape planning. Effective and optimal species management strategies can only be formulated after relationships between species distribution and environmental factors have been identified. Concerning amphibians, several approaches exist but they generally suffer from two limitations: 1) the spatial autocorrelation (i.e. the dependency between two observations) in data is rarely explicitly analyzed, even if it may affect the accuracy of species-habitat relationships models. We showed how this spatial autocorrelation can be measured and included in logistic models with the example of the agile frog (Rana dalmatina) in north-eastern Switzerland. We used the Moran's I and the autologistic model (i.e. a logistic model including a measure of the spatial arrangement of the response variables). We found that if spatial autocorrelation is not considered, then conclusions on species-habitat relationships can be incorrect. 2) The effect of landscape on amphibian occurrence in ponds is often assumed to be equal in every direction (isotropic). However, barriers and inhospitable surfaces may reduce movement patterns and the area around ponds accessible to species. This implies that the ideal circular area has in reality a shape depending on the surrounding landscape. We developed a method to determine the effect of habitat variables on amphibian species distribution, considering physical barriers in their movement around ponds. We studied two amphibian species: the common toad (Bufo bufo) and the common frog (Rana temporaria) in the Rhone plain. We demonstrated that reducing the boundaries of circular area following barriers, allowed to compute landscape predictors which better explained species distribution. These results suggested that the proposed approach is more pertinent than the traditional circular buffers analysis. Our results stress the necessity to consider barriers and ecological corridors in species distribution models in order to avoid incorrect inferences. Species distribution models are usually established for a single region. It is generally unknown whether the identified relationships between species distribution and environmental variables can be directly transferred to another geographical area. We examined landscape-level habitat relationships for six amphibian species by measuring correlations with their presence in 655 ponds of five different regions. We analyzed several models by using the information-theoretic approach and the Akaike Information criterion (AIC). For five out of six species, the best models predict that site occupation probability depends on region. Our results suggest that caution is needed when predictions of species occurrence and species management strategies are done using models built in other geographic regions. We also observed that connectivity was generally more explicative than landscape variables. In addition, we found that the spatial scale at which habitat affected species occurrence varied from pond to several km around ponds. Management strategies for amphibian conservation should be conducted taking into account the geographic context, connectivity of ponds and habitat characteristics at multiple spatial scales. Finally, we demonstrated that the landscape, separating patches in metapopulation models, has to be considered in order to avoid incorrect conclusions on population viability analyses. We explored how patch occupancy is sensitive to Euclidean (shortest) versus a landscape-based distance (least-cost). We found: 1) from a theoretical standpoint, that inter-patch landscape affects patch occupancy; 2) from a practical and conservation standpoints, which patches should be considered in priority for landscape management. The approach was illustrated in the case of two metapopulations of the Yellow-bellied Toad in the Rhone plain. We applied successfully the developed practical approaches to the case of several amphibian species, but they can doubtlessly be extended to any species functioning on a spatially defined patch basis (e.g. pond, nesting place, den …), structured as a metapopulation and affected by landscape structure during movement. By improving and combining spatially explicit approaches, we are more likely to provide wildlife managers with tools for valuable decision making.

We studied population size, genetic diversity and differentiation of common frog (Rana temporaria) populations at urban golf courses and reference natural ponds in the greater Helsinki region, southern Finland. A total of 248 tadpoles from 12 locations (six golf courses, six reference sites) were genotyped with 13 polymorphic microsatellite markers. The most urban populations, situated in northern Helsinki, were the largest breeding sites having >120 (golf courses) and >200 (reference sites) spawn clumps at the time of sampling. On average, there was no difference in the number of spawns between the anthropogenic ponds at golf courses and the natural water bodies. Genetic variation within populations was substantial (HO = 0.68) while genetic differentiation between populations was low (FST = 0.016; average distance = 17.6 km). The golf course populations did not differ from natural populations in terms of genetic variability or differentiation. Hence, our results suggest that golf courses contribute positively to urban amphibian populations by providing suitable water bodies for reproduction and green corridors for dispersal, thus preventing isolation and loss of genetic variability within populations.