Similar Ecological Requirements Research Articles

Habitat utilization of the Eurasian spoonbill (Platalea leucorodia) wintering in the Yancheng National Nature Reserve: relative importance of artificial habitats

Coastal wetlands are among the most modified habitats because of the loss and degradation of tidal flats, resulting in a rapid decline in waterbirds migrating along flyways. Understanding the relative importance of multiple types of wetlands as habitats for waterbirds and the factors influencing their utilization could improve management effectiveness. During the wintering seasons of 2021-2022 and 2022-2023, we documented the distribution of Eurasian spoonbills (Platalea leucorodia), a wetland specialist, in the Yancheng National Nature Reserve (YNNR) and quantified the surrounding environments as influencing factors to assess the relationship between their habitat use patterns and environmental characteristics. Our results showed that spoonbills inhabit common seepweed (Suaeda glauca) marshes, reed (Phragmites australis) ponds, aquaculture ponds, and agricultural channels. Although natural wetlands supported a greater number of spoonbills in the YNNR, spoonbills were able to forage in artificial wetlands. The environmental features where the spoonbills were distributed were found to influence their habitat use, and the most important factor was water depth, followed by species richness and vegetation cover. These results demonstrated that spoonbills rely on both natural and artificial wetlands in the core and buffer zones of the YNNR. Our research thus underlined that conservation interventions of natural and artificial wetlands, such as controlling the water depth and diminishing human activities, might maximize the effects of total conservation outcomes for the Eurasian spoonbills, as well as for various coastal waterbirds with similar ecological requirements.

Comparative genetic and demographic responses to climate change in three peatland butterflies in the Jura massif

Climate is a main driver of species distributions, but all species are not equally affected by climate change, and their differential responses to similar climatic constraints might dramatically affect the local species composition. In the context of climate warming, a better knowledge of the ability of dispersal-limited and habitat-specialist species to track climate change at local scale is urgently needed. Comparing the population genetic and demographic impacts of past climate cycles in multiple co-distributed species with similar ecological requirements help predicting the community-scale response to climate warming, but such comparative studies remain rare. Here, we studied the relationship between demographic history and past changes in spatial distribution of three protected peatland butterfly species (Boloria aquilonaris, Coenonympha tullia, Lycaena helle) in the Jura massif (France), using a genomic approach (ddRAD sequencing) and species distribution modeling (SDM). We found a similar and narrow thermal niche among species, and shared demographic histories of post-glacial decline and recent fragmentation of populations. Each species functions as a single metapopulation at the regional scale, with a North-South gradient of decreasing genetic diversity that fits the local dynamics of the ice cover over time. However, we found no correlation between changes in the quantity or the quality of suitable areas and changes in effective population size over time. This suggests that species ranges moved beyond the Jura massif during the less favorable climatic periods, and/or that habitat loss and deterioration are major drivers of the current dramatic decline observed in the three species. Our findings allow better understanding how history events and contemporary dynamics shape local biodiversity, providing valuable knowledge to identify appropriate conservation strategies.

Mesocarnivores activity patterns in the Northern Colombian Andes

Temporal segregation plays an important role as a coexistence mechanism between potentially competing and closely related species, especially in species with similar morphology and ecological requirements, such as mesocarnivores. This study investigates the temporal niche ecology of mesocarnivores coexisting in the southeastern Aburrá Valley, northern Colombian Andes. Specifically, this study i) evaluated the daily activity patterns of six mesocarnivore species, ii) analyzed the influence of the lunar cycle on the activity patterns of nocturnal species, iii) estimated the temporal overlap between pairs of mesocarnivores, and iv) estimated the functional similarities of these species. We hypothesized that mesocarnivores with similar functional traits exhibit greater temporal niche segregation, thus showing low overlap in their activity patterns to reduce competition. We used data from tracking cameras (10,744 camera-days) and estimated daily activity patterns using Kernel density analysis, non-negative trigonometric summation, and overlap analysis with the Overlap package in R. Also, lunar influence was evaluated using circular statistics in the software Oriana 4.02. Functional similarity was analyzed by similarity clustering using Jaccard's index in PAST. Nine species were recorded; six were included in the analyses of daily activity patterns. Activity patterns were not uniform throughout the circadian cycle. Cerdocyon thous, Leopardus tigrinus, and Nasuella olivacea showed mainly nocturnal activity, while Eira barbara, Nasua nasua, and Neogale frenata displayed a diurnal activity pattern. Only Leopardus tigrinus showed significant activity related to the lunar cycle. The activity overlap between pairs of species was variable, with a tendency to a low overlap, showing a high ecological similarity between species. This study represents the first estimate of the activity patterns of mesocarnivore species in the southeastern Aburrá Valley. The observed activity patterns are similar to those reported in other works. Species with high overlap showed ecological differences, especially in size and diet. The low number of records for some species may be associated with poor detectability but also with low abundance as a result of urban development and anthropogenic disturbance (e. g., roadkills). Our results suggest that temporal segregation contributes to mediating intra-gremial interactions and coexistence between sympatric and potentially competing species. These results will hopefully contribute to the knowledge of the ecology of mesocarnivores, mainly in ecosystems surrounding large cities in the northern Andes.

Predicting future conservation areas while avoiding sympatry in two alpine amphibians severely threatened by climate change

Climate change will cause important declines in environmental suitability, especially when living at high elevations. The critically endangered Salamandra lanzai from the Alps may be severely exposed to future climate change effects and its suitable climate niche may shrink or shift. Another Alpine salamander (S. atra) is present in the region, which in case of spatial overlap may represent a risk for S. lanzai. It is urgent to estimate the effect of future climate change on these species and identify priority areas for conservation while preventing their sympatry. With a species distribution modelling (SDM) approach, we projected the current and future climate suitability of both salamander species. We accounted for uncertainty related to the methods (model replicates) and climate projections (data source, global circulation model and scenario) to provide a consensus map for practitioners. This map also takes into account potential sympatry with S. atra by penalizing the suitability scores of S. lanzai by the scores of S. atra. We predict a severe effect of climate change on both species distributions. Most of the current habitats are projected to become largely unsuitable by 2070, regardless of the climatology and scenario. We identified important spatial disagreements between projections based on different data sources, mostly due to precipitation projections and daily temperature variation. This highlights the need to account for multiple climatologies in mountainous environments. The habitat of both species is highly fragmented, which is expected to limit distributional shifts through natural dispersion. We suggest to explore the possibility of translocation for the most threatened populations and simultaneously develop captive breeding programs. Biotic interactions are rarely accounted for in SDMs, and we encourage the documentation of species with similar ecological requirements to improve the relevance of SDMs for future conservation planning.

Group dynamics and activity patterns of two dolphin species, the Common Dolphin (Delphinus delphis) and Dusky Dolphin (Lagenorhynchus obscurus) in direct sympatry

Abstract Co-occurrence of species with similar ecological requirements could bring individual advantages, but when resources are scarce, co-occurring species would segregate to reduce competition and thus enable coexistence. We studied co-occurrence, group dynamics, and activity budgets, along with the seasonal and diel variation, of two sympatric species: the Common Dolphin (Delphinus delphis) and Dusky Dolphin (Lagenorhynchus obscurus), in Northern Patagonia, Argentina. Dolphin groups were recorded by nautical surveys between 2006 and 2018, and classified the groups by their constituent species (single- or multispecies groups), group size, age/sex composition, predominant activity, season, and time block. Frequencies were arranged in contingency tables and analyzed by log-linear models. Activity bout duration also was recorded by focal-group follows and compared using nonparametric tests. Single- and multispecies groups’ occurrence varied throughout the year, with a period of high co-occurrence in spring and summer, when both species and most of multispecies groups were present, and a period of low co-occurrence, when mostly common dolphins remained in the area. Common dolphins occur in groups of more than a hundred while dusky dolphins do so in groups of 50 animals at most. Feeding time budget was higher in Dusky Dolphin single- and multispecies groups. Common dolphins showed a seasonal and diurnal pattern in activity budget. During the period of high co-occurrence, dusky dolphins’ group size showed a diurnal pattern, and both species increased their feeding time budgets, a putative indication of more favorable foraging conditions. During this period, dusky dolphins associate occasionally in multispecies groups, increasing feeding time budget and feeding bouts duration, suggesting that the association between the two species is beneficial.

Spatial and temporal resource partitioning in a mixed-species colony of avian echolocators.

Resource partitioning may facilitate the coexistence of sympatric species with similar ecological requirements. Here, we study a colony of unusual echolocating birds called swiftlets, which nest underground on an island off the coast of Singapore. The colony comprises two congeneric swiftlet species, black-nest swiftlets (Aerodramus maximus) and edible-nest swiftlets (A.fuciphagus), nesting at high densities and in close proximity. Bioacoustic recordings and monitoring of nesting biology at the site across multiple seasons revealed significant differences in echolocation calls as well as survival rates between the species, with the larger black-nest swiftlet nesting at locations with the highest fledging rates. We also observe an additional off-season breeding peak by the smaller species, the edible-nest swiftlet. Unexpectedly, off-season egg-hatching rates were significantly higher compared with the rates during the shared breeding season (mean difference=14%). Our study on the breeding biology of these echolocating cave-dwelling birds provides an example of spatial and temporal strategies that animals employ to partition resources within a confined habitat.

Environmental shifts in and around Lake Pannon during the Tortonian Thermal Maximum based on a multi-proxy record from the Vienna Basin (Austria, Late Miocene, Tortonian)

The Neogene Lake Pannon was the largest lake that ever existed in Europe. It attained its greatest extent during the Tortonian Thermal Maximum. For the first time, results from a detailed lake record documenting about 85 kyr of Late Miocene time in a continuously recovered, 60-m-long, clay-rich core of Lake Pannon are reported. This record includes the transition from the lake's maximum transgression into its highstand at around 10.4 Ma. The environmental development of Lake Pannon during its maximum extent is interpreted based on integrated paleontological, sedimentological, mineralogical and geochemical data. The maximum extent coincided with stable sedimentation of clay, little influx from the hinterland, low surface productivity and severe bottom-water anoxia. The clay mineralogy of the lower part of the core points to prevailing chemical weathering based on the illite/smectite ratios. Distinct Fe, Mn and Ba enrichments are interpreted to have formed close to sulfate-methane transition zones during the maximum flooding. The highstand phase was marked by rapid environmental shifts with frequent phases of well‑oxygenated bottom waters. These phases are reflected by rich benthic communities including stenohaline tunicates. The increased input of detritic kaolinite suggests a shift towards physical weathering and higher precipitation coinciding with a shift in the provenance of clay minerals.Increasing amounts of nutrients stimulated surface water productivity and nannoplankton blooms. Despite the offshore position of the core at ∼8 km from the mountainous ranges of the Alps, strong fluvial input is reflected from 32.5 to 30.3 m by coarser sediment and the occurrence of terrestrial and freshwater molluscs. The Rhenodanubian Flysch Unit was the main source of the siliciclastics of the core and was drained by the Paleo-Wien river. Drainage from the Calcareous Alps was limited to an exceptionally strong fluvial event and related deposits, which documents the presence of a second river in the southwest, which might represent the Paleo-Liesing.The dominance of smectite throughout the core suggests a temperate climate with distinct seasonality during the Tortonian Thermal Maximum. In view of the autochthonous ascidian sclerites in three samples, and assuming generally similar ecological requirements for both Pannonian and modern tunicates, we conclude a polyhaline salinity for Lake Pannon around 10.4 Ma.

Dark diversity in Amazonian stream fish communities: What factors determine species absence along environmental gradients?

Abstract Species distribution models often fail to predict observed patterns of species diversity, and this is because some species within a regional pool that are tolerant of conditions at a given location may nevertheless be absent from the local community. These missing species have been termed “dark diversity”. In the present study, we investigated which factors explain dark diversity among fish assemblages in Amazonian streams. We sampled 71 streams in areas with different types of land use within two river basins and estimated dark diversity from patterns of species co‐occurrence, using Beals’ index, along environmental gradients. From this procedure, taxa are designated as dark diversity components when they are absent from a given stream, but often co‐occur with the local species at other streams, indicating similar ecological requirements. We used generalised linear models both to determine whether environmental or landscape variables, connectivity, instream environmental heterogeneity or some combination of these factors explained dark diversity of fishes, and to evaluate whether ecomorphology is associated with the extent to which a species contributes to dark diversity and which specific traits contribute the most to explaining variation in dark diversity. Mean local diversity exceeded observed dark diversity. The magnitude of dark diversity was directly associated with the proportion of secondary forest in the immediate catchment and with the index of proximity to anthropogenic impact. Species that have high affinity for environments with higher current velocity, low swimming ability and that capture food mainly on the surface contributed more to dark diversity, which suggests that swimming ability, habitat preference and aspects related to diet are key predictors of the probability that a given species will be present at locations with suitable habitat. Our findings reinforce the idea that dark diversity results from interactions between species traits and environmental factors, including anthropogenic impacts. Understanding the interplay among environmental factors and species traits that contribute to dark diversity provides targets for improved ecosystem restoration and sustainability of native species assemblages.

Limonium ksamilum (Plumbaginaceae), a new species from Albania

Limonium ksamilum, a new species is described and illustrated from southern Albania, where it grows along the calcareous rocky coast near Ksamil. It shows close taxonomical relationships with L. dictyophorum, as well as with L. himariense and L. arcuatum, with which it shares similar ecological requirements. Remarks on its morphological features, distribution, ecology, conservation status and an analytical key for the species of Limonium occurring in Albania are provided.

Water quality parameters affect dynamics of phytoplankton functional groups in Lake Hawassa, Ethiopia

The water quality of Lake Hawassa has been deteriorating due to high influent loads from various sources, including influents of a hospital, industries, hotels, and agricultural runoff, which can induce changes in Reynolds functional groups of phytoplankton (RFGs). The functional associations of algae can also be affected by the dominant zooplankton and macrophytes coverage. RFGs (species with similar ecological requirements) are indicative of water quality but have not been studied in Lake Hawassa. The functional approach detects stressor-induced changes in phytoplankton assemblages more effectively than taxonomy-based methods due to its higher discriminatory power. The main objective of this study was, therefore, to investigate the factors affecting the dynamics of RFGs in Lake Hawassa through monthly sampling (April–August in 2019) from four sites. A total of 130 species of phytoplankton were identified and classified into 17 RFGs. The dominant ten RFGs (D, J, K, LO, M, N, P, SN, TD,and W2) contributed 96.1% of the total fresh weight biomass. Redundancy analysis indicated that the RFGs were correlated significantly with electrical conductivity, dissolved oxygen, pH, turbidity, Secchi depth, and total phosphorus revealing the overriding importance of these parameters in influencing the dynamics of the algal functional assemblage in Lake Hawassa. The results supported our hypothesis that the biotic and the human-induced abiotic factors have significant impact on RFGs. Our findings could serve as baseline information for efforts directed toward water quality improvements.

Foraging behaviour of sympatrically breeding macaroni (Eudyptes chrysolophus) and chinstrap (Pygoscelis antarcticus) penguins at Bouvetøya, Southern Ocean

Species with similar ecological requirements that overlap in range tend to segregate their niches to minimize competition for resources. However, the niche segregation possibilities for centrally foraging predators that breed on isolated Subantarctic islands may be reduced by spatial constraints and limitations in the availability of alternative prey. In this study we examined spatial and trophic aspects of the foraging niches of two sympatrically breeding penguin species, macaroni (Eudyptes chrysolophus; MAC) and chinstrap (Pygoscelis antarcticus; CHIN) penguins, at Bouvetøya over two breeding seasons. To measure at-sea movements and diving behaviour, 90 MACs and 49 CHINs were equipped with GPS loggers and dive recorders during two austral summer breeding seasons (2014/15 and 2017/18). In addition, blood samples from tracked birds were analysed for stable isotopes to obtain dietary information. CHINs displayed marked interannual variation in foraging behaviour, diving deeper, utilizing a larger foraging area and displaying enriched values of δ15N in 2014/15 compared to the 2017/18 breeding season. In contrast, MACs dove to similar depths and showed similar δ15N values, while consistently utilizing larger foraging areas compared to CHINs. We suggest that low krill abundances in the waters around Bouvetøya during the 2014/15 season resulted in CHINs shifting toward a diet that increased their niche overlap with MACs. Our findings may partly explain the decreasing number of breeding CHINs at the world’s most remote island, Bouvetøya, while also highlighting the importance of characterizing niche overlap of species using multi-season data sets.

Niche partitioning between sympatric wild canids: the case of the golden jackal (Canis aureus) and the red fox (Vulpes vulpes) in north-eastern Italy

BackgroundTwo coexisting species with similar ecological requirements avoid or reduce competition by changing the extent of their use of a given resource. Numerous coexistence mechanisms have been proposed, but species interactions can also be aggressive; thus, generally a subordinate species modifies its realized niche to limit the probability of direct encounters with the dominant species. We studied niche partitioning between two sympatric wild canids in north-eastern Italy: the golden jackal and the red fox, which, based on competition theories, have a high potential for competition. We considered four main niche dimensions: space, habitat, time, and diet.ResultsWe investigated three study areas monitoring target species populations from March 2017 to November 2018 using non-invasive monitoring techniques. Red fox presence was ascertained in every study area, while golden jackal presence was not ascertained in one study area, where we collected data regarding wolf presence. Considering the two target species, we observed partial diet partitioning based on prey size, with the golden jackal mainly feeding on wild ungulates and the red fox mainly feeding on small mammals. The two canids had an extensive temporal overlap along the diel cycle, having both predominant crepuscular and nocturnal activity patterns, but marked spatial partitioning and differential use of habitats. The golden jackal proved to be specialist concerning the habitat dimension, while the red fox resulted completely generalist: the former selected less human-modified habitats and avoided intensively cultivated lands, while the latter was present in all habitats, including intensively cultivated lands.ConclusionsThe observed partitioning might be due partially to some ecological adaptations (e.g. specialist vs. generalist use of resources) and specific behaviours (e.g. cooperative vs. solitary hunting) and partially to the avoidance response of the red fox aimed at reducing the probability of direct encounters with the golden jackal.

Niche Analysis and Conservation of Bird Species Using Urban Core Areas

Knowing the ecological requirements of bird species is essential for their successful conservation. We studied the niche characteristics of birds in managed small-sized green spaces in the urban core areas of southern (Kavala, Greece) and northern Europe (Rovaniemi, Finland), during the breeding season, based on a set of 16 environmental variables and using Outlying Mean Index, a multivariate ordination technique. Overall, 26 bird species in Kavala and 15 in Rovaniemi were recorded in more than 5% of the green spaces and were used in detailed analyses. In both areas, bird species occupied different niches of varying marginality and breadth, indicating varying responses to urban environmental conditions. Birds showed high specialization in niche position, with 12 species in Kavala (46.2%) and six species in Rovaniemi (40.0%) having marginal niches. Niche breadth was narrower in Rovaniemi than in Kavala. Species in both communities were more strongly associated either with large green spaces located further away from the city center and having a high vegetation cover (urban adapters; e.g., Common Chaffinch (Fringilla coelebs), European Greenfinch (Chloris chloris), Eurasian Blue Tit (Cyanistes caeruleus)) or with green spaces located closer to the city center and having high gray area cover and anthropogenic disturbance level (urban exploiters; e.g., Western Jackdaw (Corvus monedula), House Sparrow (Passer domesticus), Eurasian Magpie (Pica pica)). The eleven species that were common to both study areas similarly used the environmental variables and had similar niches, indicating that birds respond similarly to urbanization irrespective of latitude. Sixteen species in Kavala and eleven species in Rovaniemi were identified as conservation priority species, based on their niche specialization level and conservation status. The management actions proposed for the conservation of priority species will also benefit other species with similar ecological requirements and ultimately help maintain diverse bird communities in small-sized green spaces in urban core areas.

A sunny spot: habitat management through vegetation cuts increases oviposition in abandoned fields in an endemic Mediterranean butterfly

Abstract The abandonment of agricultural land and the afforestation of grassland habitats represent major threats for butterflies in European and Mediterranean areas. A crucial goal for Lepidoptera conservation is to maintain and/or restore habitat quality by targeted management. Nevertheless, there are few experimental studies allowing to derive data‐driven strategies to protect butterflies of open grasslands in the Mediterranean region. We developed a habitat management strategy for the conservation of the Italian endemic butterfly Zerynthia cassandra by adopting a three‐step procedure: (i) characterising which environmental and host plant features influence oviposition on plants; (ii) identifying and testing the effect of a data‐driven habitat management intervention; (iii) understanding which micro‐habitat features promote Z. cassandra oviposition in restored places to optimise the intervention. Both patch (areas of 1 m radius hosting Aristolochia shoots) and plant features affect oviposition, with the strongest positive effects showed by high irradiation of the patch and plant quality (high number of flowers and leaves). Accordingly, the management consisted in vegetation cuts to increase irradiation, and 2 years of monitoring demonstrated that this procedure significantly increased oviposition (average increase of about 2 eggs per plant) and larval presence. Micro‐habitat sampling demonstrated that the maximum oviposition differed between vegetation structures, highlighting the importance of a local fine‐tuning before the intervention. We provided a data‐driven, effective, and sustainable management strategy to increase habitat suitability and oviposition for an endemic and endangered Mediterranean butterfly. Our framework can drive management strategies for other species with similar ecological requirements and subjected to similar threats.

Niche shift of tephritid species after the Oriental fruit fly (Bactrocera dorsalis) invasion in La Réunion

AbstractAimIn a context of successive fruit fly invasions (Tephritidae), this study investigated how the top invader, Bactrocera dorsalis, displaced established fruit fly populations. We focused, particularly, on how this invasion impacted the host range and climatic niche of each resident species.LocationLa Réunion, France, Indian Ocean.MethodsWe collected fruit from more than 100 plant species across the island, in cultivated and non‐cultivated areas at different altitudes in order to monitor the emergence of fruit flies. Fruit collection was conducted over two field campaigns: from 2001 to 2009, before the B. dorsalis invasion; and from 2018 to 2019, after the B. dorsalis invasion. We compared the distribution and host range of fruit fly species for the two periods.ResultsOur results confirmed the generalist character of B. dorsalis, with the infestation of 52 out of 112 of the fruit species collected in the field. After the B. dorsalis invasion, we observed a shift in the host range and spatial distribution of established tephritids. The host range of specialist species that only share a few host species with B. dorsalis did not change significantly. On the contrary, we observed a significant shift in diversity or proportion of host range and climatic niches for the generalist species, such as Bactrocera zonata, Ceratitis quilicii and Ceratitis capitata.Main conclusionsWe provide evidence of the competitive displacement induced by B. dorsalis on other established species. The coexistence between B. dorsalis and generalist Ceratitis species seems possible because they have different responses to climatic conditions or the capacity to exploit other host fruit species. In contrast, the coexistence of B. zonata with B. dorsalis seems to be compromised because both species have similar ecological requirements. This research provides useful information for managing invasions, particularly since understanding competitive displacements is essential for the identification of empty niches and for modelling potential species distribution.

Recommendations for IUCN Red List Conservation Status of the “Dryophytes immaculatus Group” in North East Asia

Threat assessment is important to prioritize species conservation projects and planning. The taxonomic resolution regarding the status of the “Dryophytes immaculatus group” and the description of a new species in the Republic of Korea resulted in a shift in ranges and population sizes. Thus, reviewing the IUCN Red List status of the three species from the group: D. immaculatus, D. suweonensis and D. flaviventris and recommending an update is needed. While the three species have similar ecological requirements and are distributed around the Yellow Sea, they are under contrasting anthropological pressure and threats. Here, based on the literature available, I have applied all IUCN Red List criterion and tested the fit of each species in each criteria to recommend listing under the appropriate threat level. This resulted in the recommendation of the following categories: Near Threatened for D. immaculatus, Endangered following the criteria C2a(i)b for D. suweonensis and Critically Endangered following the criteria E for D. flaviventris. All three species are declining, mostly because of landscape changes as a result of human activities, but the differences in range, population dynamics and already extirpated subpopulations result in different threat levels for each species. Dryophytes flaviventris is under the highest threat category mostly because of its limited range segregated into two subpopulations; and several known extirpated subpopulations. Immediate actions for the conservation of this species are required. Dryophytes suweonensis is present in both the Republic of Korea and the Democratic Republic of Korea (DPR Korea) and is under lower ecological pressure in DPR Korea. Dryophytes immaculatus is present in the People’s Republic of China, over a very large range despite a marked decline. I recommend joint efforts for the conservation of these species.

Niche overlap between two sympatric frugivorous Neotropical primates: improving ecological niche models using closely-related taxa

Ecological niche models (ENMs) are widely used tools for predicting species geographic distribution as a function of environmental variables. The inclusion of biotic factors in the predictor suite can significantly increase the predictive power of such models, leading to a model closer to the realized niche for the species under investigation. In this study, we provide evidence of niche overlap between gray woolly monkeys (Lagothrix cana) and black-faced black spider monkeys (Ateles chamek) based on locality and ecological data covering their complete geographic range in the Amazon forests of Brazil, Peru and Bolivia. We also estimate the potential distribution of L. cana using environmental predictors, and the distribution of A. chamek as a biotic factor. Finally, we quantified current and future habitat loss and areas under legal protection. We found that only 39% of the L. cana area of occupancy is under legal protection and that the species could potentially lose up to 58% of habitat in the next 30 years. We also show that the use of a closely-related species that has a more robust dataset can improve ENMs of poorly studied, rare and/or cryptic species. The framework developed here can be applied to a wide range of sympatric species if they share similar ecological requirements. Since our focal species are the most frugivorous primates in our study region and especially vulnerable to habitat loss, the identification of highly suitable areas for both taxa can help to protect other forest-dwelling species, reducing the rate of overall biodiversity loss.

Blue Sheep Resource Selection in Alpine Grasslands of a Western Himalayan Landscape - A Point Process Approach.

In-depth knowledge of distribution and factors influencing it is important for species conservation and management. Many forms of such data have led to the development of new analytical techniques for better interpretation. For mountainous terrains with certain limitations, species data are obtained in the presence-only form. The point process model is one of the recent approaches for modelling such data, taking care of pseudo-absences and spatial independence. For conservation in regions with limited resources and species with similar ecological requirements, it is important to properly assess the extent of competition extent between wild and domestic species. We attempted to use point process framework to estimate the function of resource selection in blue sheep (Pseudois nayaur) in areas influenced by pastoralism in a western Himalayan region. Our study is the first attempt to use this framework to estimate resource selection on a dataset not collected using radio-telemetry. Spatial locations of blue sheep and livestock and a background sample of random points with six topographic covariates were used to model resource selection probability via intensity function. Blue sheep showed its predicted presence in areas with open vegetation coinciding with alpine meadows, influenced by southern aspect keeping a threshold distance of 600-1000 m from cliffs (escape terrain). Livestock, also showed presence probability in open vegetation, but at lower altitudes, mainly on valley floors. Our results suggest that though blue sheep continued to use the same habitat type after livestock arrival, they selected different resources based on topographic factors. Livestock were in areas where it was convenient for pastoralists to establish campsites and where nutritious grasses were present, making it feasible to graze. Thus, we argue that the probable shift in habitat for blue sheep from optimal areas occurs due to livestock presence, which might disturb their nutritional balance. Our study provides helpful insights for managing rangelands, which when tied with dietary patterns will give a better idea for proper conservation measures in the future.

Interdependent Phenotypic and Biogeographic Evolution Driven by Biotic Interactions.

Biotic interactions are hypothesized to be one of the main processes shaping trait and biogeographic evolution during lineage diversification. Theoretical and empirical evidence suggests that species with similar ecological requirements either spatially exclude each other, by preventing the colonization of competitors or by driving coexisting populations to extinction, or show niche divergence when in sympatry. However, the extent and generality of the effect of interspecific competition in trait and biogeographic evolution has been limited by a dearth of appropriate process-generating models to directly test the effect of biotic interactions. Here, we formulate a phylogenetic parametric model that allows interdependence between trait and biogeographic evolution, thus enabling a direct test of central hypotheses on how biotic interactions shape these evolutionary processes. We adopt a Bayesian data augmentation approach to estimate the joint posterior distribution of trait histories, range histories, and coevolutionary process parameters under this analytically intractable model. Through simulations, we show that our model is capable of distinguishing alternative scenarios of biotic interactions. We apply our model to the radiation of Darwin's finches-a classic example of adaptive divergence-and find limited support for in situ trait divergence in beak size, but stronger evidence for convergence in traits such as beak shape and tarsus length and for competitive exclusion throughout their evolutionary history. These findings are more consistent with presympatric, rather than postsympatric, niche divergence. Our modeling framework opens new possibilities for testing more complex hypotheses about the processes underlying lineage diversification. More generally, it provides a robust probabilistic methodology to model correlated evolution of continuous and discrete characters. [Bayesian; biotic interactions; competition; data augmentation; historical biogeography; trait evolution.].

Assessing environmental response of gastropod species in karst springs: what species response curves say us about niche characteristic and extinction risk?

Spring ecosystems are exceptionally threatened and their conservation is often emphasized due to high levels of endemism among the groups inhabiting these ecosystems. This study includes gastropod assemblages of 36 springs situated in the northwestern part of Bosnia and Herzegovina. The aims of this paper were: to determine key factors for distribution of gastropod species on microspatial scale; to define the environmental preferences of gastropod species with respect to the physicochemical properties of water, the hydrological characteristics and the sediment structure; to determine species tolerance ranges and species optimums, with special emphasis on new and endemic species. Moreover the aim was to identify the species with highest extinction risk. The contribution of endangered and rare species to the total density was extremely high (64.6%). Species Response Curves were used to predict the distribution of gastropod species along the environmental gradient in the spring environments for the first time. The most important factors in structuring gastropod spring assemblages were oxygen and temperature. HOF (Huisman–Olff–Fresco) models may determine differences in range of environmental tolerance of species with similar ecological requirements. Our results have shown that two species: Ancylus fluviatilis and A. recurvus may be distinguished by their species response curves. Although there are no data on conservation status of A. recurvus, the extinction risk should be inferred as high, suggesting that IUCN status for this species should be updated to the category Vulnerable. Our study using HOF models revealed the potential gastropod species useful as indicators of karstic springs.