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Molecular methods can play a crucial role in species management and conservation. Despite the usefulness of genetic approaches, they are often not explicitly included as part of species recovery plans and conservation practises. The Natterjack toad (Epidalea calamita) is regionally Red-Listed as Endangered in Ireland. The species is declining and is now present at just seven sites within a highly restricted range. This study used 13 highly polymorphic microsatellite markers to analyse the population genetic diversity and structure. Genetic diversity was high with expected heterozygosity between 0.55 and 0.61 and allelic richness between 4.77 and 5.92. Effective population sizes were small (Ne < 100 individuals), but not abnormal for pond breeding amphibians. However, there was no evidence of historical or contemporary genetic bottlenecks or high levels of inbreeding. We identified a positive relationship between Ne and breeding pond surface area, suggesting that environmental factors are a key determinant of population size. Significant genetic structuring was detected throughout the species' range, and we identified four genetic entities that should be considered in the species' conservation strategies. Management should focus on preventing further population declines and future loss of genetic diversity overall and within genetic entities while maintaining adequate local effective population size through site-specific protection, human-mediated translocations and head-start programs. The apparent high levels of genetic variation give hope for the conservation of Ireland's rarest amphibian if appropriately protected and managed. [ABSTRACT FROM AUTHOR]

The global amphibian crisis is driven by a range of stressors including disease, habitat loss, and environmental contamination. The role of climate change remains poorly studied and is likely to influence environmental suitability, ranges, reproduction, and phenology. This study aimed to characterize the bioclimatic‐habitat niche space of the Natterjack toad (Epidalea calamita) throughout its European range and to assess the impact of climate on the toad's environmental suitability and breeding behavior in Ireland, where declines in recent decades have resulted in it being regionally Red‐Listed as Endangered. To address these questions, we first identified which climate variables best predict the current bioclimatic niche, fecundity (number of eggs deposit), and phenology. We then used future climate projections for two time periods (2041–2060 and 2061–2080) and two greenhouse gas emission scenarios (RCP 4.5 and RCP 8.5) to predict how the species range, fecundity, and phenology would change. The European range of the species was found to be limited by winter temperatures while its bioclimatic niche varied markedly throughout its range. Species distribution models suggested projected climate change will increase environmental suitability for the species throughout its range, including Ireland, but most notably in Scandinavia and the Baltic. Fecundity in Ireland was greatest during the cool temperatures of spring and after wet winters associated with ephemeral breeding pool availability. Warm, dry summers in the preceding year influenced fecundity the following spring indicative of carryover effects. Initiation of spawning was driven by spring temperatures, not rainfall. Projections suggested future climate change may increase fecundity in Ireland while spawning may commence earlier throughout the 21st century especially under a high greenhouse gas emission scenario (RCP 8.5). Despite recent range contraction and population declines due to habitat deterioration, the Natterjack toad, if subject to a suitable species conservation strategy, has the potential to be a climate change winner, notwithstanding unpredictable habitat and land‐use change, sea‐level rise inducing coastal erosion, changes in invertebrate prey abundance, and disease. [ABSTRACT FROM AUTHOR]

Amphibian declines are of major conservation concern worldwide. The Natterjack toad (Epidalea calamita) is the rarest amphibian in Ireland, regionally Red-listed as Endangered. The species is at the north-western edge of its European range in Ireland and is subject to substantial conservation efforts, including regular monitoring and surveillance, a pond creation agri-environment scheme, and a head-start and translocation programme to facilitate pond colonisation. We used large-scale intensive monitoring and surveillance data from 2004 to 2018 to quantify temporal trends in egg string production analysing breeding site preferences and occurrence of perceived threats and pressures. Despite substantial conservation efforts, egg string production declined by 23% in Ireland over a 14-year period (−1.6%/year). Twenty-two of 100 artificial ponds had been colonised by 2018, but artificial sites accounted for <10% of eggs laid and had prevented further declines by only 4%. Natterjack toad spawning was associated with ponds with a large surface area, situated in sand dune habitat, with high water conductivity, and a high percentage cover of aquatic vegetation at the substrate with short terrestrial vegetation in the surrounding vicinity. Threats and pressures are related to poor water quality at breeding sites and abandonment of surrounding agricultural land leading to unsuitable terrestrial vegetation. Given the Natterjack toad's population trend in Ireland, continued monitoring and surveillance is vital, while we advocate protection of occupied sand dunes, active engagement with farmers and landowners to ensure compliance with habitat maintenance recommendations and improved habitat connectivity to facilitate colonisation of artificial ponds. [ABSTRACT FROM AUTHOR]