Marsh Frog (Rana ridibunda Pall.) in Cooling Ponds in the Middle Urals

Environmental conditions in cooling ponds of thermal power plants are favorable for marsh frogs. Their populations inhabiting Verkhne-Tagil and Reftinskoe reservoirs differ in some traits, such as size and age composition, growth rate after metamorphosis, spawning type, fecundity, and characteristics of larval development. Differentiation in body size manifests itself at the early stages of terrestrial life and progresses at later stages. As a consequence, larger individuals may reach maturity and participate in reproduction at an earlier age.     

Toward reassessing data‐deficient species

One in 6 species (13,465 species) on the International Union for Conservation of Nature (IUCN) Red List is classified as data deficient due to lack of information on their taxonomy, population status, or impact of threats. Despite the chance that many are at high risk of extinction, data‐deficient species are typically excluded from global and local conservation priorities, as well as funding schemes. The number of data‐deficient species will greatly increase as the IUCN Red List becomes more inclusive of poorly known and speciose groups. A strategic approach is urgently needed to enhance the conservation value of data‐deficient assessments. To develop this, we reviewed 2879 data‐deficient assessments in 6 animal groups and identified 8 main justifications for assigning data‐deficient status (type series, few records, old records, uncertain provenance, uncertain population status or distribution, uncertain threats, taxonomic uncertainty, and new species). Assigning a consistent set of justification tags (i.e., consistent assignment to assessment justifications) to species classified as data deficient is a simple way to achieve more strategic assessments. Such tags would clarify the causes of data deficiency; facilitate the prediction of extinction risk; facilitate comparisons of data deficiency among taxonomic groups; and help prioritize species for reassessment. With renewed efforts, it could be straightforward to prevent thousands of data‐deficient species slipping unnoticed toward extinction.     

Assessment of environmental quality of water bodies next to agricultural areas of Buenos Aires province (Argentina) by means of ecotoxicological studies with Rhinella arenarum

Over the last decade, oysters in the Bay of Veys (Northwest France) have sporadically experienced significant summer mortality events which appear to be due to a combination of extrinsic and intrinsic factors. In the present work, the involvement of pesticides (as additional stressors) was investigated using both artificial exposure and field studies (at two sites). Six herbicides were detected in seawater following tests for a total of 15 herbicides. The most estuarine site was the most contaminated, showing relatively high values compared with those recorded in a neighboring river. No pesticides were detected in the flesh of oysters in the field but exposure experiments led to an accumulation of two substituted ureas (diuron and isoproturon, from 0.5 μ g/L and 1 μ gL^{? 1} respectively). Some physiological effects were observed in terms of reproduction (partial spawning) and histopathology (atrophy of the digestive tubule epithelium) but results related to other tissue alterations and to neutral red retention (NRR) assays were not conclusive and require further investigation.     

Projected Climate Impacts for the Amphibians of the Western Hemisphere

Abstract: Given their physiological requirements, limited dispersal abilities, and hydrologically sensitive habitats, amphibians are likely to be highly sensitive to future climatic changes. We used three approaches to map areas in the western hemisphere where amphibians are particularly likely to be affected by climate change. First, we used bioclimatic models to project potential climate‐driven shifts in the distribution of 413 amphibian species based on 20 climate simulations for 2071–2100. We summarized these projections to produce estimates of species turnover. Second, we mapped the distribution of 1099 species with restricted geographic ranges. Finally, using the 20 future climate‐change simulations, we mapped areas that were consistently projected to receive less seasonal precipitation in the coming century and thus were likely to have altered microclimates and local hydrologies. Species turnover was projected to be highest in the Andes Mountains and parts of Central America and Mexico, where, on average, turnover rates exceeded 60% under the lower of two emissions scenarios. Many of the restricted‐range species not included in our range‐shift analyses were concentrated in parts of the Andes and Central America and in Brazil's Atlantic Forest. Much of Central America, southwestern North America, and parts of South America were consistently projected to experience decreased precipitation by the end of the century. Combining the results of the three analyses highlighted several areas in which amphibians are likely to be significantly affected by climate change for multiple reasons. Portions of southern Central America were simultaneously projected to experience high species turnover, have many additional restricted‐range species, and were consistently projected to receive less precipitation. Together, our three analyses form one potential assessment of the geographic vulnerability of amphibians to climate change and as such provide broad‐scale guidance for directing conservation efforts.     

Patterns and biases of climate change threats in the IUCN Red List

International Union for Conservation of Nature (IUCN) Red List assessments rely on published data and expert inputs, and biases can be introduced where underlying definitions and concepts are ambiguous. Consideration of climate change threat is no exception, and recently numerous approaches to assessing the threat of climate change to species have been developed. We explored IUCN Red List assessments of amphibians and birds to determine whether species listed as threatened by climate change display distinct patterns in terms of habitat occupied and additional nonclimatic threats faced. We compared IUCN Red List data with a published data set of species’ biological and ecological traits believed to infer high vulnerability to climate change and determined whether distributions of climate change‐threatened species on the IUCN Red List concur with those of climate change‐threatened species identified with the trait‐based approach and whether species possessing these traits are more likely to have climate change listed as a threat on the IUCN Red List. Species in some ecosystems (e.g., grassland, shrubland) and subject to particular threats (e.g., invasive species) were more likely to have climate change as a listed threat. Geographical patterns of climate change‐threatened amphibians and birds on the IUCN Red List were incongruent with patterns of global species richness and patterns identified using trait‐based approaches. Certain traits were linked to increases or decreases in the likelihood of a species being threatened by climate change. Broad temperature tolerance of a species was consistently related to an increased likelihood of climate change threat, indicating counterintuitive relationships in IUCN assessments. To improve the robustness of species assessments of the vulnerability or extinction risk associated with climate change, we suggest IUCN adopt a more cohesive approach whereby specific traits highlighted by our results are considered in Red List assessments. To achieve this and to strengthen the climate change‐vulnerability assessments approach, it is necessary to identify and implement logical avenues for further research into traits that make species vulnerable to climate change (including population‐level threats).     

溪洛渡水电站对两栖爬行动物多样性影响的预测与保护对策

采用β多样性指数和动物地理学方法研究了溪洛渡水电站对两栖爬行动物多样性的影响,结果表明,在海拔600m以下淹没区的区系与600－900m区段的区系,共有种最多,相似性最大,隔离与分化最小,它们具有较近的生物地理学关系,它们与海拔900m以上的区段则有明显差别,因此,保护好海拔600－900m区段的物种多样性成为保护该地物种多样性的关键,并可以有效地降低电站的建设对物种多样性的影响。     

Determinants of chorus tenure in barking treefrogs (Hyla gratiosa)

In all species of anuran amphibians studied to date, male mating success is positively correlated with male chorus tenure (the number of nights that a male is present in breeding aggregations), yet males spend only a small portion of the total breeding season in choruses. Three hypotheses might explain abbreviated chorus tenure in anuran amphibians: (1) mortality, (2) energy limitations, and (3) movement among choruses. I tested these hypotheses in a study of the barking treefrog (Hyla gratiosa), a species with very abbreviated chorus tenure. Mortality accounted for the short tenures of some males: an estimated 20% of males died while calling in the chorus. Energy limitations were an important determinant of chorus tenure. Males lost weight over successive nights in the chorus, and males with longer chorus tenures were in better condition on their first night in the chorus, lost condition more slowly, and were in poorer condition on their last night in the chorus than were males with shorter chorus tenures. Males that I fed crickets as they left the chorus returned sooner and for more nights than did control (unfed) males. Movement between ponds did not explain abbreviated chorus tenure: less than 16% of the males called at more than one pond, and these males increased their chorus tenures by a median of only 2.5 nights by calling in another chorus. Thus, abbreviated chorus tenure in H. gratiosa appears to be primarily the result of energy limitations, with mortality playing a secondary role.     

Importance of Habitat Quality and Landscape Connectivity for the Persistence of Endangered Natterjack Toads

Abstract: The natterjack toad (Bufo calamita) is endangered in several parts of its distribution, including Belgium, where it occurs mainly in artificial habitats. We parameterized a general model for natterjack population viability analysis (PVA) and tested its sensitivity to changes in the values of basic parameters. Then we assessed the relative efficiency of various conservation measures in 2 situations: a small isolated population and a system of 4 populations connected by rare dispersal movements. We based the population viability analysis on a stage‐structured model of natterjack population dynamics. We parameterized the model in the RAMAS GIS platform with vital rates obtained from our own field experience and from published studies. Simulated natterjack populations were highly sensitive to habitat quality (particularly pond drying), to dispersal from surrounding local populations, and to a lesser extent to values of fecundity and survival of terrestrial stages. Population trajectories were nearly insensitive to initial abundances, carrying capacities, and the frequency of extreme climatic conditions. The simulations showed that in habitats with highly ephemeral ponds, where premetamorphosis mortality was high, natterjack populations nearly always had a very high extinction risk. We also illustrated how low dispersal rates (<1 dispersing individual/generation) efficiently rescued declining local populations. Such source‐sink dynamics demonstrate that the identification and management of source populations should be a high priority.     

The Contribution of Habitat Loss to Changes in Body Size, Allometry, and Bilateral Asymmetry in Two Eleutherodactylus Frogs from Puerto Rico

Abstract:  Amphibian populations have been declining worldwide and the exact mechanisms underlying these changes are not well understood. We examined environmentally induced phenotypic changes that may reflect ongoing stresses on individuals and therefore their ability to persist in increasingly changing landscapes. Specifically, we evaluated the contribution of habitat loss on the size, allometry, and levels of fluctuating asymmetry of Eleutherodactylus antillensis and E. coqui , 2 common species that are endemic to Puerto Rico. We x-rayed frogs collected at 9 sites that differed in the amount of forest cover and measured their snout-vent, radio-ulna, femur, and tibio-fibula lengths. E. antillensis and E. coqui were smaller in the highly disturbed (≤20% forest cover) than in the intermediately (20–70% forest cover) and little-disturbed (≥70% forest cover) landscapes. In E. antillensis but not in E. coqui , the slope and intercept of the curves relating snout-vent length with the length of the 3 bones differed with degree of forest cover, suggesting an effect of habitat loss on body shape. In E. antillensis and E. coqui , differences between right and left sides corresponded to true fluctuating asymmetry; however, only the radio-ulna length of E. coqui showed a trend toward an increase in fluctuating asymmetry with habitat loss. Because body size scales with a variety of physiological, life history, and ecological traits, conservation programs aimed at monitoring morphological changes in amphibians may help in understanding the mechanisms that contribute to their persistence in changing environments.