Citizen science reveals sharp decline of the Mediterranean tree frog Hyla meridionalis over 40 years in southeastern Iberia: potential causes and proposed solutions to prevent regional extinction

The non-indigenous red swamp crayfish (Procambarus clarkii) has been shown to be a threat for amphibian conservation. Many amphibian species breed in temporary ponds to diminish predation risk as such ecosystems are free of large predators. However P. clarkii, occurring as an invasive species in the Camargue delta, can readily disperse on the ground and thus colonize isolated ponds. We studied the current impact of the exotic crayfish on the reproductive success of the Mediterranean tree frog (Hyla meridionalis). In a mesocosm experiment, we tested the effect of two crayfish densities (1 and 3 crayfish/m2) on tadpole abundance. We also tested in a field experiment, within a temporary pond, the crayfish’s predation on the tree frog’s eggs. Finally, we developed site occupancy models using data from 20 ponds to assess the effect of crayfish abundance on tadpole abundance. Neither the experiments, nor the site occupancy models showed a negative impact of the current crayfish abundance on the tree frog populations breeding in ponds. We found that recorded crayfish densities were lower than in other areas where crayfish has impacted amphibian populations, but we hypothesize that current crayfish abundance in the area may increase in the future, thus impacting tree frog populations.

Marine protected areas (MPAs) are a primary tool for the stewardship, conservation, and restoration of marine ecosystems, yet 69% of global MPAs are only partially protected (i.e., are open to some form of fishing). Although fully protected areas have well‐documented outcomes, including increased fish diversity and biomass, the effectiveness of partially protected areas is contested. Partially protected areas may provide benefits in some contexts and may be warranted for social reasons, yet social outcomes often depend on MPAs achieving their ecological goals to distinguish them from open areas and justify the cost of protection. We assessed the social perceptions and ecological effectiveness of 18 partially protected areas and 19 fully protected areas compared with 19 open areas along 7000 km of coast of southern Australia. We used mixed methods, gathering data via semistructured interviews, site surveys, and Reef Life (underwater visual census) surveys. We analyzed qualitative data in accordance with grounded theory and quantitative data with multivariate and univariate linear mixed‐effects models. We found no social or ecological benefits for partially protected areas relative to open areas in our study. Partially protected areas had no more fish, invertebrates, or algae than open areas; were poorly understood by coastal users; were not more attractive than open areas; and were not perceived to have better marine life than open areas. These findings provide an important counterpoint to some large‐scale meta‐analyses that conclude partially protected areas can be ecologically effective but that draw this conclusion based on narrower measures. We argue that partially protected areas act as red herrings in marine conservation because they create an illusion of protection and consume scarce conservation resources yet provide little or no social or ecological gain over open areas. Fully protected areas, by contrast, have more fish species and biomass and are well understood, supported, and valued by the public. They are perceived to have better marine life and be improving over time in keeping with actual ecological results. Conservation outcomes can be improved by upgrading partially protected areas to higher levels of protection including conversion to fully protected areas.

Habitat loss and transformation are major threats to biodiversity and ecosystem functioning, but their effects on species interaction are often poorly understood. We evaluated effects of habitat transformation and seasonality on anuran-prey food webs in Colombian dry-forests. We asked whether anthropic transformation (anthropic vs natural) and/or seasonality (dry, minor and major rain seasons) affect predator load on arthropods, the occurrence of energetic bottlenecks, and the diet overlap of anurans. We selected six dry forest sites in the Caribbean of Colombia, sampled anurans, and identified their stomach contents to construct anuran-prey food webs. We show that the global structure of food webs was affected by disturbance and seasonality, but not by their interaction. Prey vulnerability was higher in anthropic habitats. Habitat transformation enhanced diet overlap among predators, but there was not a differential effect of habitat type according to seasonality for network metrics. Our study shows a strong effect of natural vegetation modification in tropical dry forest on anuran-prey food webs, while seasonality did not seem to further mediate these effects.

Summary The aim of this study was to assess the temporal transferability of species distribution models (SDMs) and their potential implications for bird conservation. We quantified the loss and fragmentation of Montagu’s Harrier Circus pygargus and Common Kestrel Falco tinnunculus habitats over 13 years (2001–2014) in a highly dynamic landscape in north-western Spain. For this purpose, priority habitats for the target species were modelled at four different spatial scales using an ensemble forecasting framework. To explore the temporal transferability of our ensemble predictions, the models were back-projected to the land cover conditions in 2001 and evaluated using historical occurrence data. In addition, models calibrated with historical data were projected to the land cover conditions in 2014 and evaluated using updated occurrence data. Changes in availability and connectivity of suitable habitats between both years were estimated at four spatial scales from a set of widely-used indicators. SDMs showed a good predictive accuracy but with limited temporal transferability due to changes in the species-habitat relationships between 2001 and 2014. The results showed a decrease in the avaliability of suitable habitats of 33.4% and 47.7% for Montagu’s Harrier and Common Kestrel, respectively; with the subsequent increase in their fragmentation. However, our estimates were found to be strongly dependent on the scale of analysis and model transferability. Changes in habitat availability and connectivity ranged from -48% to +54% for Montagu’s Harrier, and from +116% to +5.6% for Common Kestrel. We call for caution when using SDMs beyond the model calibration time period to guide bird conservation. This is especially important for raptors, often characterised by low population sizes and large home ranges, and particularly sensitive to unstable, highly dynamic environmental conditions. In light of these results, specific, long-standing monitoring protocols remain essential to ensure accurate modelling performance and reliable future projections.

The IUCN criteria 2001 are considered one of the best methods to evaluate species extinction risk at the global and regional levels. The aim of this work is to test the applicability of the IUCN criteria to peripheral isolated plant populations (PIPPs). PIPPs have been a topic of scientific debate in Conservation Biology for about 15 years and international conventions such as ESPC address the issue of their conservation. Conservation measures often rely on Red Lists based on IUCN criteria, but there is little evidence supporting their application to PIPPs. In this work, we tested the hypothesis that PIPPs’ intrinsic restricted range and rarity lead to the overestimation of their extinction risk. We compared and analyzed four IUCN criteria (A, B, C, D), considering 17 species with PIPPs in different Italian administrative regions. Special attention must be given to the spatial scale at which PIPPs are assessed, the evaluation of the threats affecting the populations, and their decline. PIPPs should not be assessed within political boundaries and we propose a new area designation that better corresponds to the characteristics of PIPPs. Criterion B is strongly biased by restricted range and overestimates the extinction risk of PIPPs, particularly when the population decline is only suspected and not observed. In this case, criterion D more accurately assesses the status of PIPPs. Criterion A is also suitable for assessing PIPPs, because it is not affected by their phytogeographic rarity. The proposed statements could also be valid for the global assessment of narrow endemic species.

This study introduces a novel approach to leverage high-resolution historical climate data and opportunistically collected historical species occurrence data for detecting adaptive responses to global change. We applied this procedure to the temperature data and the most comprehensive Iberian dataset of dung beetle occurrences as an illustrative example. To understand how populations of different species are responding, we devised a procedure that compares the temporal trend of spatial and temperature variables at the locations and times of all the occurrence data collection (overall trend) with the specific temporal trends among the occurrences of each species. The prevalence of various species responses is linked to life history or taxonomic characteristics, enabling the identification of key factors influencing the propensity to experience different effects from climate change. Our findings suggest that nearly half of the Iberian dung beetle species may be adversely affected by temperature increases, with a geographic shift being the most common response. The results generated through the proposed methodology should be regarded as preliminary information, serving to formulate hypotheses about the diverse responses of species to climate change and aiding in the selection of candidate species capable of coping with challenges posed by changing temperatures.

The worldwide erosion of biological diversity has not spared amphibians which are amongst the most affected taxa with numerous extinct or near-extinct species. Our knowledge of the status and ecology of amphibians of Algeria is still limited whereas local natural habitats are fast disappearing under a strong anthropogenic pressure. Eighty two localities were sampled between 1996 and 2010, to survey the amphibian community within Numidia, North-Eastern Algeria. Nine species, three Urodeles (Pleurodeles poireti, Pleurodeles nebulosus and Salamandra algira and six Anurans (Bufo bufo spinosus, Bufo mauritanicus, Bufo viridis, Discoglossus pictus, Hyla meridionalis and Pelophylax saharicus) were found within the region. Results suggest a marked, rapid and unexplained crash of the Algerian Newt Pleurodeles poireti, a species endemic to a small area in and around Djebel Edough (Annaba). Information on the status (abundance and distribution) of each recorded taxon is provided and conservation measures are discussed in the light of an apparent local decline of Anurans and the vulnerability of three species (S. algira, P. nebulosus and B. bufo spinosus).

Threatened tree species across conservation zones in a nature reserve of North-Western Vietnam

Population dynamics and life-history ofCoeloglossum viride(L.) Hartm.: an endangered orchid species in The Netherlands

The North African amphibian fauna was once regarded as limited in diversity, but increased field and laboratory research in the region has subsequently revealed considerable endemism and data such as these are necessary for making objective and justifiable recommendations for conservation. Our research, coupled with findings from the literature, allow an up-to-date analysis of distribution, status of populations, and actual and potential threats to the continued survival of all species within Tunisia. The Tunisian batrachofauna currently consists of seven species grouped in seven genera: Pleurodeles, Bufotes, Discoglossus, Bufo, Amietophrynus, Pelophylax, and Hyla. Whereas other species are characterized by wider distributions from north to south, Bufo spinosus appears restricted to the mountainous northwestern corner where major protected areas occur. Pleurodeles nebulosus and Hyla meridionalis appear restricted to humid, subhumid, and semi-arid localities in northern Tunisia, in the Khroumirie region, but also within the Mogod region, around Tunis and the Cap Bon Peninsula. Northern localities represent the most humid and temperate portion of the country and support the highest habitat and species diversity. Despite an increasing number of man-made habitats (irrigation canals), southern localities continue to suffer from lack of suitable habitat due to natural and human causes. There are no manmade ponds dedicated to protect amphibian species in Tunisia. Our observations confirmed that Tunisia is affected by amphibian population decline, due especially to loss and fragmentation of habitat. Principal threats to amphibian survival (uncontrolled urban extension, alteration and destruction of habitat, pollution, road kills, and introduction of several predator species) vary slightly from north to south. Implementation of stricter policies coupled with increased public education and awareness is recommended in order to preserve Tunisia’s amphibian fauna.

Cumulative habitat loss increases conservation threats on endemic species of terrestrial vertebrates in Mexico

More amphibians are threatened through loss of habitat than any other single factor. Conservation measures to restore habitat are dependent on historical data indicating the original extent of a species. When historical data is absent, disjunct distributions create a special problem for conservationists who need to determine whether they have an anthropogenic cause. The Endangered western leopard toad (Amietophrynus pantherinus) has a disjunct distribution in the south-western tip of South Africa. We use mitochondrial sequences from 153 individuals to show that the disjunct distribution is unlikely to have an anthropogenic origin. Two distinct populations are separated by 100 km, with highest probability for the most recent common ancestor arising some 5 Kya. The causes of this disjunct distribution appear to be too recent to be attributable to changes in sea level; instead we suggest that there was a range retraction associated with a distinct drying period in the area during the Holocene, possibly indicating that this species will be susceptible to future climate change. Further, we find that the eastern population is less genetically diverse and appears to be undergoing a serious reduction in range, despite its occurrence in the least urbanized habitat. Conservation measures suggested include surveys for breeding sites in the eastern population, custodian agreements for existing breeding sites and foraging areas and the need for a Biodiversity Management Plan to be drawn up and implemented.

Steppe lands in Europe are critically affected by habitat loss and fragmentation, and hold over 50% of IUCN Red List bird species in Europe. Dupont’s Lark is a threatened steppe-specialist passerine whose European geographic range is restricted to Spain, with less than 2000 pairs and an annual population decline of − 3.9%. Its strongly fragmented habitat leads to a metapopulation structure in the Iberian Peninsula that includes 24 populations and 100 subpopulations. We present an updated Population Viability Analysis based on the latest scientific knowledge regarding distribution, population trends, breeding biology and connectivity. Our results predict metapopulation extinction in 2–3 decades, through a centripetal contraction process from the periphery to the core. The probability of extinction in 20 years was 84.2%, which supports its relisting to Endangered in Spain following IUCN criteria. We carried out a sensitivity analysis showing that some parameters, especially productivity and survival of adults and juveniles, help to increase metapopulation viability. Simulation of management scenarios showed that habitat restoration in a subset of key subpopulations had a positive effect on the overall metapopulation persistence. Translocations of a limited number of individuals from source to recipient locations may help to rescue the most endangered subpopulations without reducing the global time to extinction of the metapopulation. In addition, we identified the most critical areas for action, where local populations of the species are prone to extinction. This work suggests that the viability of the Dupont’s Lark metapopulation could be improved and its risk of extinction reduced if urgent and localized conservation measures are applied. In the short-term, habitat loss and fragmentation due to ploughing, reforestation and infrastructures implementation in Dupont’s Lark habitat must be avoided. Habitat restoration and translocations could help to avoid imminent extinction of critical subpopulations. Restoration of extensive grazing is recommended as the most effective way to achieve the long-term conservation of Dupont’s Lark in Spain.

No safe haven: Protection levels show imperilled South African reptiles not sufficiently safe-guarded despite low average extinction risk

Climate-related extreme weather events can result in the loss of drinking water access. We assessed the relative vulnerability of 3143 United States (U.S.) counties to loss of drinking water access due to droughts, floods, and cyclones. Five vulnerability assessment models from the literature were compared, each differing in the aggregation method used to combine the three determinants of vulnerability (V) – exposure (E), sensitivity (S), and adaptive capacity (AC). Exposure scores were calculated using historical occurrence data, sensitivity scores were determined from the intrinsic resilience of the drinking water technologies, and adaptive capacity scores were calculated from nine socioeconomic indicators. Our results showed that models V = E + S + AC and V = E + S–AC were the same, as were models V = E × S × AC and V = E × S ÷ AC. Between these two model forms (form 1: V = E + S + AC and V = E + S–AC; form 2: V = E × S × AC and V = E × S ÷ AC), scores from one model form could be used to predict scores from the second model form, with R-squared values ranging from 0.61 to 0.82 depending on the extreme weather event type. A fifth model, V = (E–AC) × S was not found to correlate with any of the other four models. We used V = E + S + AC as our reference model as this resulted in a more uniform distribution of counties in each of the five intervals of vulnerability. Comparing the vulnerability scores identified the counties with greatest vulnerability to losing access to drinking water due to floods, droughts, and cyclones. Our results can be used to inform evidence-based decisions such as allocation of resources and implementation of adaptation strategies.