30 research outputs found

    Geographic separation and genetic differentiation of populations are not coupled with niche differentiation in threatened Kaiser's spotted newt (Neurergus kaiseri)

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    The combination of niche modelling and landscape genetics (genomics) helps to disentangle processes that have shaped population structure in the evolutionary past and presence of species. Herein, we integrate a comprehensive genomic dataset with ecological parameters and niche modelling for the threatened Kaiser's newt, a newt species adapted to mountain spring-ponds in Iran. Genomic analysis suggests the existence of two highly differentiated clades North and South of the Dez River. Genetic variation between the two clades (76.62%) was much greater than within clades (16.25%), suggesting that the Dez River prevented gene flow. River disconnectivity, followed by geographic distance, contributed mostly to genetic differentiation between populations. Environmental niche and landscape resistance had no significant influence. Though a significant difference between climatic niches occupied by each clade at the landscape-scale, habitat niches at the local-scale were equivalent. 'Niche similarity analysis' supported niche conservatism between the two clades despite the southward shift in the climatic niche of the Southern clade. Accordingly, populations of different clades may occupy different climatic niches within their ancestral niche. Our results indicate that the change of climatic conditions of geographically and genetically separated populations does not necessarily result in the shift of an ecological niche

    Phylogeny and species delimitation of near Eastern Neurergus newts (Salamandridae) based on genome-wide RADseq data analysis

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    We reconstruct the molecular phylogeny of Near Eastern mountain brook newts of the genus Neurergus (family Salamandridae) based on newly determined RADseq data, and compare the outcomes of concatenation-based phylogenetic reconstruction with species-tree inference. Furthermore, we test the current taxonomy of Neurergus (with four species: Neurergus strauchii, N. crocatus, N. kaiseri, and N. derjugini) against coalescent-based species-delimitation approaches of our genome-wide genetic data set. While the position of N. strauchii as sister species to all other Neurergus species was consistent in all of our analyses, the phylogenetic relationships between the three remaining species changed depending on the applied method. The concatenation approach, as well as quartet-based species-tree inference, supported a topology with N. kaiseri as the closest relative to N. derjugini, while full-coalescent species-tree inference approaches supported N. crocatus as sister species of N. derjugini. Investigating the individual signal of gene trees highlighted an extensive variation among gene histories, most likely resulting from incomplete lineage sorting. Coalescent-based species-delimitation models suggest that the current taxonomy might underestimate the species richness within Neurergus and supports seven species. Based on the current sampling, our analysis suggests that N. strauchii, N. derjugini and N. kaiseri might each be subdivided into further species. However, as amphibian species are known to be composed of deep conspecific lineages that do not always warrant species status, these results need to be cautiously interpreted in an integrative taxonomic framework. We hypothesize that the rather shallow divergences detected within N. kaiseri and N. derjugini likely reflect an ongoing speciation process and thus require further investigation. On the contrary, the much deeper genetic divergence found between the two morphologically and geographically differentiated subspecies of N. strauchii leads us to propose that N. s. barani should be considered a distinct species, Neurergus barani Öz, 1994

    Body size and digestive system shape resource selection by ungulates : a cross-taxa test of the forage maturation hypothesis

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    The forage maturation hypothesis (FMH) states that energy intake for ungulates is maximised when forage biomass is at intermediate levels. Nevertheless, metabolic allometry and different digestive systems suggest that resource selection should vary across ungulate species. By combining GPS relocations with remotely sensed data on forage characteristics and surface water, we quantified the effect of body size and digestive system in determining movements of 30 populations of hindgut fermenters (equids) and ruminants across biomes. Selection for intermediate forage biomass was negatively related to body size, regardless of digestive system. Selection for proximity to surface water was stronger for equids relative to ruminants, regardless of body size. To be more generalisable, we suggest that the FMH explicitly incorporate contingencies in body size and digestive system, with small-bodied ruminants selecting more strongly for potential energy intake, and hindgut fermenters selecting more strongly for surface water.DATA AVAILABILITY STATEMENT : The dataset used in our analyses is available via Dryad repository (https://doi.org/10.5061/dryad.jsxksn09f) following a year-long embargo from publication of the manuscript. The coordinates associated with mountain zebra data are not provided in an effort to protect critically endangered black rhino (Diceros bicornis) locations. Interested researchers can contact the data owner (Minnesota Zoo) directly for inquiries.https://wileyonlinelibrary.com/journal/elehj2022Mammal Research InstituteZoology and Entomolog

    The ecology of roe deer (Capreolus capreolus) and muntjac (Muntiacus reevesi) in a forested landscape in eastern England

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    Assessing Landscape Connectivity and Dispersal Corridors for Goitered gazelle in Central Iran

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    Long-term survival of Goitered gazelles in central Iran has been threatened because of isolation of existing populations and genetic threats. Effective management of these small and isolated populations needs to evaluate landscape connectivity among core habitat patches. In the present study, resistance surfaces were mapped as a function of twelve uncorrelated variables using species distribution algorithms. Given the limited empirical data of Goitered gazelle dispersal distances, we assessed different dispersal ability scenarios. Extent of core habitats, fracture zones, and dispersal corridors were identified using resistance kernel approach. Our finding showed that while gazelle population in Biduiyeh Protected Area has been isolated, there is relatively high dispersal rate among populations of Goitered gazelle in Mooteh National Park, Ghamishloo National Park, Kahyaz Protected Area, Kalmand-Bahadoran Protected Area and Kolah-Qazi National Park. Given the effect of roads and metropolises, functional connectivity between Kolah-Qazi and other populations is not possible. Based on genetic relationships and landscape connectivity results, we concluded that gazelle populations in Central Iran can be grouped into three separated subpopulations including 1- Biduiyeh P.A., 2-Kolah-Qazi N.P., and 3- gazelles in other protected areas. The obtained results show that integrated conservation management at landscape level need to be considered in maintaining gene flow among isolated and fragmented habitats

    Spatial Conservation Prioritization of Persian Squirrel Based on Habitat Suitability and Climate-Induced Forest Mortality Risk

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    The Zagros forests in Iran are currently experiencing an exacerbation of climate-induced mortality, placing the Persian squirrel, a keystone species reliant on these ecosystems, in jeopardy. Addressing this imminent threat, our research employed a spatial prioritization methodology, integrating assessments of habitat suitability and mortality risk. Utilizing a weighted ensemble approach, incorporating the strengths of diverse models and expert rules, we discerned that approximately 62% of surveyed forests are at risk, with 7% classified as high risk and 17% as very high risk. Notably, 83% of the forests exhibited varying degrees of habitat suitability, with 11% and 12% demonstrating high and very high suitability, respectively. Employing a conservation prioritization framework, we systematically categorized habitats into priority classes, with 8%, 17%, 29%, and 46% assigned to very high, high, moderate, and low conservation priority classes, respectively. Significantly, areas classified as very high priority demand immediate restoration efforts due to ongoing mortality, while other priority classes underscore the importance of protection and prevention in unaffected habitats. Acknowledging the irreversible nature of current climatic conditions in the Zagros forests, our strategic emphasis aligns with conservation triage principles, prioritizing the preservation of intact habitats yet to succumb to irreversible mortality

    Human dimensions of wildlife conservation in Iran: Assessment of human-wildlife conflict in restoring a wide-ranging endangered species.

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    Human-wildlife conflicts restrict conservation efforts, especially for wide-ranging animals whose home ranges overlap with human activities. We conducted a study to understand conflicts with, and factors influencing the perceived value of an expanding population of onagers (Equus hemionus onager) in local communities in southern Iran. We asked about locals' perceptions of six potential management strategies intended to lessen human-onager conflict. We found that human-onager conflict was restricted to 45% of respondents within the Bahram-e-Goor Protected Area, all of whom were involved in farming or herding activities. Locals within the protected area were more knowledgeable about onagers and valued onagers more than those living outside the protected area. The perceived value of onagers increased with level of education, total annual income, and perceptions of onager population trends; the perceived value of onagers decreased with the magnitude of conflict between onagers and locals. To tolerate or avoid conflicts with onagers, locals were supportive of monetary compensation and changing from a traditional lifestyle to industrialized farming (for farmers) or livestock production (for herders) with the help of government; locals did not support selling land to the government. Our study is among the first in human-wildlife conflict and local attitudes towards an endangered species and its recovery in Iran. We conclude that current levels of human-onager conflict are relatively low and perceived value of onagers is still relatively high. Therefore, wildlife authorities should consider the development of mitigation strategies with local communities before conflicts intensify

    Nest-Site Selection and Breeding Success of the Semi-Desert Bird, Grey Hypocolius Hypocolius Ampelinus, in Relation to Plant Structure of Ziziphus Nummularia

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    Nest-site selection and breeding success of the Grey Hypocolius (Hypocolius ampelinus) were surveyed in relation to plant structure in 2010 and 2011 in southwestern Iran. Microhabitat parameters such as Ziziphus nummularia as the main shrubs used for nesting, were measured in 20 × 20 m plots around the nest and compared with random plots. There were no best clear model for predicting the nest-site selection, however, plant variables especially the canopy cover and diameter of the Z. nummularia, were the most important determinant for nest-site selection (wi = 0.5). Grey Hypocolius preferred areas with a higher density of Z. nummularia than other available habitats (28.21 vs 1.2 of cover). There was no strong predictor for breeding success, the best models incorporated either Z. nummularia density or diameter (with model weights of 0.25 and 0.17, respectively). Nests of Grey Hypocolius had a higher chance of success at higher densities of Z. nummularia in nesting plots. We found that a higher density of Z. nummularia improved both the probability of nest-site selection and the breeding success of Grey Hypocolius. Shrubs with greater diameters were more likely to be selected for nesting, but had lower breeding success. To identify the key reasons of nests being successful, more habitat parameters should be monitored. The majority of failure in breeding occurred during the incubation stage (52%)

    MaxEnt brings comparable results when the input data are being completed; Model parameterization of four species distribution models

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    Abstract Species distribution models (SDMs) are practical tools to assess the habitat suitability of species with numerous applications in environmental management and conservation planning. The manipulation of the input data to deal with their spatial bias is one of the advantageous methods to enhance the performance of SDMs. However, the development of a model parameterization approach covering different SDMs to achieve well‐performing models has rarely been implemented. We integrated input data manipulation and model tuning for four commonly‐used SDMs: generalized linear model (GLM), gradient boosted model (GBM), random forest (RF), and maximum entropy (MaxEnt), and compared their predictive performance to model geographically imbalanced‐biased data of a rare species complex of mountain vipers. Models were tuned up based on a range of model‐specific parameters considering two background selection methods: random and background weighting schemes. The performance of the fine‐tuned models was assessed based on recently identified localities of the species. The results indicated that although the fine‐tuned version of all models shows great performance in predicting training data (AUC > 0.9 and TSS > 0.5), they produce different results in classifying out‐of‐bag data. The GBM and RF with higher sensitivity of training data showed more different performances. The GLM, despite having high predictive performance for test data, showed lower specificity. It was only the MaxEnt model that showed high predictive performance and comparable results for identifying test data in both random and background weighting procedures. Our results highlight that while GBM and RF are prone to overfitting training data and GLM over‐predict nonsampled areas MaxEnt is capable of producing results that are both predictable (extrapolative) and complex (interpolative). We discuss the assumptions of each model and conclude that MaxEnt could be considered as a practical method to cope with imbalanced‐biased data in species distribution modeling approaches
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