Search

Organisms with multiple biotic attributes may also have conflicting niche determinants, and we assessed whether the realized niche reflects single or multiple biotic attributes. A group of all‐female salamanders found in eastern North America (unisexual salamanders; Ambystoma spp.) embody two potentially competing biotic states: hybridism and obligate reproductive parasitism. In theory, hybrids should occupy areas that are transitional to those used by parental species, parasites must live in syntopy with their hosts, and parasites that engage in ecological competition with hosts should be most successful in habitats that are moderately suitable for hosts. We built niche models for bisexual salamanders (Ambystoma laterale and Ambystoma jeffersonianum), as well as for unisexual Ambystoma that posses nuclear DNA from both of these species. These unisexuals are both phenotypic hybrids and obligate reproductive parasites of the bisexual species. We characterized realized niches predicted for unisexual Ambystoma via a hybrid‐framework model (e.g., using environmental predictors) and a parasite‐framework model (e.g., using host suitability predictors). Model validation using ancillary data permitted evaluation of which biotic state (hybrid vs. parasite) fit the observed patterns of occupancy. The hybrid model conformed strongly with predictions that the unisexual niche would be transitional between A. laterale and A. jeffersonianum bisexuals. Average annual temperatures and terrestrial salamander species richness (a proxy for competition) were particularly descriptive of parental niches and hybrid occupancy of transitional environments. While the parasite model behaved as expected, model validation did not fully corroborate its utility for determining patterns of occupancy. Instead, model selection revealed that the hybrid model was more descriptive of unisexual occurrence than the parasite model. Despite the fundamental importance of reproductive parasitism to the persistence of unisexual Ambystoma, we suggest that hybridism has greater contribution to the realized niche. When species have competing ecological attributes, one primary biotic state may dominate as a determinant of the realized niche. [ABSTRACT FROM AUTHOR]

Seasonal animal migration is a widespread phenomenon. At the species level, it has been shown that many migratory animal species track similar climatic conditions throughout the year. However, it remains unclear whether such a niche tracking pattern is a direct consequence of individual behaviour or emerges at the population or species level through behavioural variability. Here, we estimated seasonal niche overlap and seasonal niche tracking at the individual and population level of central European white storks (Ciconia ciconia). We quantified niche tracking for both weather and climate conditions to control for the different spatio-temporal scales over which ecological processes may operate. Our results indicate that niche tracking is a bottom-up process. Individuals mainly track weather conditions while climatic niche tracking mainly emerges at the population level. This result may be partially explained by a high degree of intra- and inter-individual variation in niche overlap between seasons. Understanding how migratory individuals, populations and species respond to seasonal environments is key for anticipating the impacts of global environmental changes. [ABSTRACT FROM AUTHOR]

Life in extreme environments is possible through multilevel adaptations to physical and biotic stresses. At high elevations, species face numerous challenges, besides low oxygen levels, but previous studies have focused on genetic and physiological adaptations to chronic hypoxia while overlooking other key strategies for thriving in alpine landscapes.Here, we investigate resource‐use trait adaptations to extreme elevations using pikas as a model, lagomorphs distributed up to 6,200 m and reaching maximum diversity on the Qinghai‐Tibet plateau, the highest plateau on Earth. Specifically, we assess cranial evolution in pikas using geometric morphometric and phylogenetic comparative techniques to determine whether adaptations among high‐elevation biota shown at the molecular and physiological levels also occur in resource‐use traits. We further explore the roles of two contrasting lifestyles (burrowing and rocky‐dwelling) in cranial evolution.We found that alpine species exhibit striking phenotypic specialization to distinct microhabitats. Contrary to physiological and genetic adaptive convergence, we show that the cranium has undergone adaptive divergence likely reflecting past resource competition in highlands and long‐term association with alpine landscapes. Our analyses also reveal that the evolution of burrowing lifestyle allows high‐elevation pikas to explore novel niches and boosts their phenotypic diversification. In addition to cold and hypoxia tolerance, high cranial specialization, the appearance of burrowing habits and strong niche separation explain how pikas overcome alpine stresses and flourish on the highest plateau on Earth. By contrast, when moving to spatially complex and heterogeneous vegetation zonation, pikas exhibit generalist skull forms able to exploit diverse habitats. These findings mirror previously reported intraspecific patterns in mammals, suggesting a general morphological response in resource‐exploiting traits to cope with distinct selection pressures across elevation zones. Phenotypic diversity is further constrained by rocky habitats, resulting in convergent skulls.Our study highlights that adaptations to extreme environments occur at multiple levels of organization, but can lead to distinct evolutionary paths depending on which selective forces they respond to. The evolution of burrowing behaviour represents a landmark in the evolutionary history of pikas. We further show that rocky habitats impose strong ecological pressures, leading to convergent responses in resource‐use traits, which is rarely documented in mammals. [ABSTRACT FROM AUTHOR]

Background and aims -- The hypothesis of ecological niche conservatism postulates that closely related species share ecologically similar environments; that is, they tend to maintain the characteristics of their fundamental niche over time. The objective of this study is to evaluate the similarity and equivalence of the ecological niches among species of the genus Zaluzania (Asteraceae), characteristic of the Mexican arid and semi-arid regions, to infer their potential niche conservatism. Methods -- Based on critically reviewed herbarium occurrence data, potential distribution models for eight species of Zaluzania were generated using the MaxEnt algorithm. The overlap between potential distribution areas was then evaluated using equivalence and ecological niche parameters implemented in the ENMTools software; for this we quantified the degree of overlap and similarity between the niches using the equivalence (D) and similarity (I) parameters. Key results -- The resulting models show that species display areas of high suitability along the Mexican dry regions, as well as overlapping heterogeneous values. All models showed high AUC (Area Under the Curve) values (> 0.8). The D and I values between each pair of species showed low values of overlap. Conclusions -- Each species of the genus shows a fundamental niche distinct from their sister species. The genus thus offers an example of niche divergence among species, with each one adapting to different environmental pressures. Our results do not support the hypothesis of niche conservatism in the genus, suggesting that the species evolved in divergent environments. [ABSTRACT FROM AUTHOR]

This study aims to verify the concept of niches at multiple spatial scales in plant communities. To this end, we analyzed the niche characteristic of Rhododendron dauricum plant communities in Northeast China at three spatial scales. At the local scale, we calculated the Importance Value (IV) of species in five communities in the north of the Da Hinggan Mountains. At the intermediate scale, we examined five communities in their entirety, calculated the niche breadth of the species, and integrated niche overlap and interspecific association to analyze interspecific relationships. Further, the generalized additive model (GAM) was used to analyze the impact of topography and soil factors on niche characteristics. At the regional scale, we analyzed the geographical distribution of dominant species of R. dauricum plant communities in Northeast China and used principal component analysis (PCA) to analyze the impact of geographical and climate factors on species distribution. The results show that at the local scale, the IV of the species in each community varies widely. At the intermediate scale, species with a wide niche breadth tend to have a high value for IV. Larix gmelinii, Betula platyphylla, R. dauricum, Ledum palustre, and Vaccinium vitis-idaea had a relatively wide niche breadth and a high niche overlap, and the interspecific associations were almost all positive. Elevation and soil nutrients were the most dominant environmental factors. At the regional scale, species with a wide niche breadth tend to have a wide range of distribution, and temperature and precipitation were the most dominant environmental factors. This study suggests that the niche characteristics at three scales are both related and different. Niche characteristics at the local scale were various and labile, and niche characteristics at the intermediate and regional scales were relatively regular. These results show some degree of consistency with previous studies from an evolutionary perspective. The action mechanisms of these communities are related to differences in the dominant environmental factors. In addition, the integration of niche overlap and interspecific association determine interspecific relationships more accurately. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Ecologists have achieved much progress in the study of mechanisms that maintain species coexistence and diversity. In this paper, we reviewed a wide range of past research related to these topics, focusing on five theoretical bodies: (1) coexistence by niche differentiation, (2) coexistence without niche differentiation, (3) coexistence along environmental stress gradients, (4) coexistence under non-equilibrium versus equilibrium conditions, and (5) modern perspectives. Results: From the review, we identified that there are few models that can be generally and confidently applicable to different ecological systems. This problem arises mainly because most theories have not been substantiated by enough empirical research based on field data to test various coexistence hypotheses at different spatial scales. We also found that little is still known about the mechanisms of species coexistence under harsh environmental conditions. This is because most previous models treat disturbance as a key factor shaping community structure, but they do not explicitly deal with stressful systems with non-lethal conditions. We evaluated the mainstream ideas of niche differentiation and stochasticity for the coexistence of plant species across salt marsh creeks in southwestern Denmark. The results showed that diversity indices, such as Shannon–Wiener diversity, richness, and evenness, decreased with increasing surface elevation and increased with increasing niche overlap and niche breadth. The two niche parameters linearly decreased with increasing elevation. These findings imply a substantial influence of an equalizing mechanism that reduces differences in relative fitness among species in the highly stressful environments of the marsh. We propose that species evenness increases under very harsh conditions if the associated stress is not lethal. Finally, we present a conceptual model of patterns related to the level of environmental stress and niche characteristics along a microhabitat gradient (i.e., surface elevation). Conclusions: The ecology of stressful systems with non-lethal conditions will be increasingly important as ongoing global-scale climate change extends the period of chronic stresses that are not necessarily fatal to inhabiting plants. We recommend that more ecologists continue this line of research. [ABSTRACT FROM AUTHOR]

Understanding the conditions under which interacting species can persist is a major goal in ecology. Dietary partitioning is one of the major strategies that enables ecologically similar species to coexist in communities. In this study, we examined the dietary patterns of a selected group of amphibians in an amphibian community in northern Sri Lanka to understand differential resource use by coexisting species. The stomach flushing method was used to examine the diet of amphibians to study the niche breadth and pairwise species dietary niche overlap. Seventeen different prey categories were identified from the diet of six species of amphibians in the community. The most frequently used prey category by all amphibians was hymenoptera. Among the amphibians, some consumed several different prey categories (8–9 prey categories), while some were more specialised (e.g. Uperodon rohani fed only on ants), consuming only one or two different prey categories. The average niche overlap among the species in the community was 0.392 indicating low trophic niche overlap. This study indicates a low level of dietary niche overlap between the selected amphibian species and hence, a high degree of dietary niche partitioning. The findings also provide valuable insights into the dietary ecology of these amphibians, which will be invaluable for the formulation of conservation strategies. [ABSTRACT FROM AUTHOR]

Objective: To assess the existing fundamental niche, potential distribution and degree of niche overlap for the three main Colombian malaria vectors Anopheles albimanus, Anopheles darlingi and Anopheles nuneztovari in the major malaria endemic Pacific region.Methods: We used models based on presence records and Normalised Difference Vegetation Index (NDVI) data, created using the maximum entropy algorithm.Results: The three vector species occupied heterogeneous environments, and their NDVI values differed. Anopheles albimanus had the largest niche amplitude and was distributed mainly on coastal areas. Environmentally suitable areas for An. albimanus and An. nuneztovari were the dry forest of inter-Andean Valleys in south-western Colombia, as confirmed for An. albimanus during model validation. There was a slight degree of niche overlap between An. darlingi and An. nuneztovari, and the species co-occurred in humid forests, predominantly in riparian zones of the San Juan and Atrato rivers.Conclusion: The information obtained may be used for the implementation of vector control interventions in selected priority areas to reduce malaria risk in this region while optimising resources. [ABSTRACT FROM AUTHOR]

The construction of the Three Gorges Reservoir (TGR), the largest dam in the world, created novel spatial and seasonal fluctuations in food availability along the Yangtze River. We studied changes in diet and niche overlap of three co-occurring catfish species between the upper and lower sections of the TGR and across four hydrological seasons to investigate whether the diets of native catfish species reflect the fluctuations in food availability. Zoobenthos dominated the diets of the three species in the upper section, but shrimp made the bulk of the diet in the lower section. This was the case in every season except during the rising-water season when all three species increased the consumption of allochthonous foods. Diet breadth was significantly broader in the upper section relative to the lower section, and expanded during the rising-water season in the lower section. Niche overlap was significantly lower in the upper section than in the lower section. A non-significant trend of reduced niche overlap during the rising-water season was observed in both sections. Our results suggest that, in less than a decade, dietary plasticity facilitated the adaptation of these species to novel habitats and a shifted food-resource base formed by the impoundment. Impoundment of the Yangtze River formed the largest reservoir in the world and led to spatial and seasonal fluctuations in food availability for native fish. In less than a decade, dietary plasticity facilitated the adaptation of three generalist catfish species to the novel habitats formed by the dam. This study enhances understanding of mechanisms that allow generalist species to maintain co-occurring populations in such dramatically changing habitats. [ABSTRACT FROM AUTHOR]

Variation in prey availability can cause changes in species interactions among marine predators. Foraging theory predicts that niche breadth will expand when resources become limited, possibly leading to higher niche overlap among sympatric species; however, a species' niche can become constrained by interactions with other similar species, resulting in an inability to shift niche breadth or position. In coastal Newfoundland, Capelin Mallotus villosus is the main forage fish species and its availability (i.e. biomass) during the summer has varied considerably following a population collapse in the 1990s. During the summer, non‐breeding Great and Sooty Shearwaters Ardenna gravis and A. grisea migrate and aggregate at annually persistent Capelin spawning sites. We used stable isotope ratios (δ13C, δ15N) of blood components (plasma, red blood cells) to investigate variation in isotopic niche breadth (95% prediction ellipse areas) and overlap of the two shearwater species during 2014, 2015 and 2016. Capelin availability varied among years, illustrated by lower peak biomass in 2015 (0.126 g/m²) and 2016 (0.027 g/m²) relative to 2014 (0.254 g/m²). The isotopic niche breadth (plasma) of both shearwater species expanded similarly from 2014 (0.65–0.66‰²) to 2015 (2.22–2.57‰²) and 2016 (1.15–1.42‰²), suggesting the incorporation of alternative prey types into their diet during years of lower prey availability. Isotopic niche overlap between Great and Sooty Shearwaters remained high across years (44–63%), however, providing little evidence for dietary niche partitioning during years of lower prey availability. Findings suggest that both shearwater species are flexible foragers and can modify their diet during the non‐breeding season to accommodate fluctuations in prey availability. [ABSTRACT FROM AUTHOR]

This study described the diet and niche overlap of four lizards from an urban fragment in Amapá state. The samplings were performed through pitfall traps and active visual search. In the stomach analysis, Formicidae and Coleoptera represented 50.79% of the total items. The highest niche overlap value was between Gonatodes humeralis and Tropidurus hispidus, which was not expected due to habitat use. The foraging strategies of all lizards observed have been previously mentioned by several authors. Several studies cite the diet of lizards being basically composed of invertebrates, with few variations, as also demonstrated in this study. [ABSTRACT FROM AUTHOR]

The sub-Himalayan dipterocarp forests of subtropical region in northwest India support 17 species of woodpecker. From a conservation perspective it is necessary to assess the ecological requirements of woodpeckers in these biologically diverse landscapes, which are experiencing habitat modification and decline in some woodpeckers. We studied the foraging niche differentiation among ten sympatric woodpeckers in the sub-Himalayan forests of northwest India: Dendrocopos canicapillus, D. macei, Picus chlorolophus, P. xanthopygaeus, P. canus, Dinopium shorii, D. benghalense, Chrysophlegma [Picus] flavinucha, Chrysocolaptes lucidus, and Mulleripicus pulverulentus. We examined the foraging site preferences of individual woodpecker species and explored the role of inter-specific differences in foraging behaviour as a possible mechanism for their coexistence. Observations on foraging woodpeckers were taken vis-a-vis the following niche dimensions: diameter of the foraging tree, height of the foraging bird, type of substrate on which it was foraging, vertical position with respect to canopy, condition of the forage tree and condition of the substrate. Distinct preferences were evident among species in their foraging tree diameters, foraging heights, vertical positions, and choice of substrate type, while preference for dead substrates was not an important distinguishing factor. Species that overlapped in one dimension generally segregated along other dimensions. Niche segregation in forage tree diameter was associated with body weight. Based on their overall niche overlaps species could broadly be differentiated into groups according to body size viz. small (3 species), medium (3 species), large (3 species), and very large (1 species). Our study demonstrates that differentiation in foraging may be a likely mechanism for coexistence of sympatric woodpeckers in this region. Given that larger species prefer larger substrates, removal of mature trees could affect their abundance, and homogenisation of stand structure could lead to impoverishment of woodpecker diversity. [ABSTRACT FROM AUTHOR]

Syntopic species with similar anatomic configuration may face strong competition for trophic resources, thus relying on developed mechanisms to ensure coexistence. The present study investigated the influence of body size on trophic interactions between juveniles of two closely related fish species at three sandy beaches in south-eastern Brazil. A total of 150 fish were sampled, where 103 were identified as Trachinotus carolinus (mean ± SE: weight = 9 g ± 1.13) and 47 as Trachinotus goodei (weight = 46.7 g ± 3.34). A significant size-difference between juvenile Trachinotus was detected by a null-model analysis (P = 0.04), with T. carolinus (TL = 79.6 mm ± 2.4) presenting a smaller body size than T. goodei (TL = 147.7 mm ± 4.2). The main prey items consumed by T. carolinus were Perna perna (IAi = 0.76) and Emerita brasiliensis (IAi = 0.18), whereas the latter was the major T. goodei dietary prey (IAi = 0.71). Both prey were correlated with larger-sized juveniles of each pompano species, whereas smaller fish shared non-preferred trophic items. Such opportunistic behaviour of smaller juveniles may account for the dietary overlap detected between the Trachinotus species (P = 0.09). Size-related dietary partitioning was observed for the largest T. goodei juveniles, which displayed only a slight overlap with T. carolinus, and between juveniles belonging to the small and medium size groups of each pompano species. Therefore, food partitioning related to pompano body size seems to be especially important for the smallest juveniles, as they present the highest vacuity (particularly T. carolinus) in the sampled beaches, suggesting that these individuals are under intra- and interspecific competitive pressure, which may affect local coexistence. [ABSTRACT FROM AUTHOR]

The development of the isotopic niche, an n-dimensional hypervolume (with n being the number of isotopes) occupied by a population in delta space, has revolutionized the study of animal interactions in wild populations. While the isotopic niche offers a useful means to understand interactions at many ecological resolutions (e.g., individual, population, community, ecosystem), a variety of intrinsic and extrinsic factors drive isotopic variability and influence the ultimate geometry of observed niche dimensions. Here, we provide an updated synthesis to guide the application of bulk stable isotope ratios to study ecological niches. We summarize progress in the application of bulk stable isotope ratios for evaluating niches to synthesize a formal definition of the isotopic niche. We identify six broad categories to describe drivers of isotopic variance introduced by the animal, its environment, and the researcher, and provide recommendations to account for such variations before, during, and after sample collection and data analyses. Our synthesis illustrates the considerations that should be made before employing the isotopic niche to broader ecological contexts, and offers guidance for the use and interpretation of isotopic niche dynamics in future studies. [ABSTRACT FROM AUTHOR]

Summary: Related plants are often hypothesized to interact with similar sets of pollinators and herbivores, but this idea has only mixed empirical support. This may be because plant families vary in their tendency to share interaction partners.We quantify overlap of interaction partners for all pairs of plants in 59 pollination and 11 herbivory networks based on the numbers of shared and unshared interaction partners (thereby capturing both proportional and absolute overlap). We test for relationships between phylogenetic distance and partner overlap within each network; whether these relationships varied with the composition of the plant community; and whether well‐represented plant families showed different relationships.Across all networks, more closely related plants tended to have greater overlap. The strength of this relationship within a network was unrelated to the composition of the network's plant component, but, when considered separately, different plant families showed different relationships between phylogenetic distance and overlap of interaction partners.The variety of relationships between phylogenetic distance and partner overlap in different plant families probably reflects a comparable variety of ecological and evolutionary processes. Considering factors affecting particular species‐rich groups within a community could be the key to understanding the distribution of interactions at the network level. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Corsican Painted Frog Discoglossus montalentii has received little research attention since its discovery, which creates uncertainty about its distribution and conservation status. We here use a combination of field surveys, ecological niche modelling (ENM) and niche overlap analyses to (i) update the D. montalentii distribution; (ii) determine its potential range, and (iii) assess if presence of Discoglossus sardus influences that of D. montalentii. Our surveys reveal presence of D. montalentii at low and mid-altitudes throughout Cap Corse and near the north-western coast, while ENMs suggest that similar climatically and topographically suitable habitats occur beyond the confirmed range in northern- and westernmost Corsica. No evidence for competitive exclusion by D. sardus was found, with both species displaying broad niche overlap at macroscale. Whether potential differences between these species do exist at microhabitat level remains worth exploring. We finally review the conservation status of D. montalentii , and assemble practical knowledge to inform future conservation assessments. [ABSTRACT FROM AUTHOR]

Despite the importance of shredders in organic matter processing in streams, information about the habitat specificities of different taxa is scarce. Herein, we evaluated the habitat preferences of invertebrate shredders in tropical forest streams. A total of 72 leaf patches were sampled in three Atlantic Forest streams (SE Brazil). For each sample, 20 environmental variables were measured, including water properties and characteristics of the leaf patch. We used an Outlying Mean Index analysis to evaluate the niche breadth and overlap of each taxon found as well as habitat preferences. In total, we found 14 shredder taxa in 68 leaf patches, and the gradient of environmental conditions influenced the distribution of most taxa. Considering taxa that occurred in atypical habitats in the study sites, Blaberidae (semiaquatic cockroaches) and Trichodactylus fluviatilis (Decapoda) showed niche segregation, while Macrobrachium potiuna (Decapoda), Tupiperla (Plecoptera), and Nectopsyche (Trichoptera) showed niche overlap. On the other hand, Heterelmis (Coleoptera), Stenochironomus (Diptera), Phylloicus major, and Triplectides gracilis (Trichoptera) occurred in typical habitats. These results showed that shredder taxa had different habitat preferences. The observed differences in niche breadths and habitat specificities among taxa probably result in different leaf processing rates across leaf patches in Atlantic Forest streams. [ABSTRACT FROM AUTHOR]

Minimal annual rainfall in arid environments results in low productivity ecosystems with fluctuating food availability. Large mammalian predators that require frequent consumption of vertebrate prey tend to be less abundant in desert environments; however, such environments often support numerous large‐bodied carnivorous reptiles. Diet is a fundamental component of an animal's ecology, and we explore the diets of three coexisting, sympatric Varanus species occurring in arid Australia: V. tristis, V. gouldii and V. panoptes. We hypothesized that the diet of varanids living in arid environments would primarily consist of relatively abundant invertebrate prey, and that vertebrate prey items would largely be limited to opportunistically consumed mammalian carrion and small reptilian species. All three Varanus species had high dietary overlap and broad, generalist diets. Invertebrate prey, particularly Orthoptera, were key to the diets of all three species. Vertebrate prey was infrequently consumed by all three Varanus species; however, when consumed, tended to comprise small reptilian species and mammalian carrion. Unlike large mammalian predators, varanids can survive on invertebrate prey and infrequent feeds and can aestivate when conditions become unfavourable, contributing to their success in arid environments. [ABSTRACT FROM AUTHOR]

Anurans living in species-rich assemblages may experience acoustic niche overlap. To deal with potential masking interference during reproductive activity, species can present acoustic partitioning based on differences in calling period. Studies addressing this question in tropical assemblages have mainly focused on the seasonal scale, and little is known about nightly variation in calling. Here, we reported on phenology and abundance of five tropical anuran assemblages at both seasonal and daily scale and tested the effects of temperature and relative humidity on calling activity patterns of 19 species. Based on 420 hourly acoustic surveys, an overall peak of calling activity in between the first and fourth hour after sunset was identified by Rayleigh's circular test, with a gradual decrease until sunrise. This nightly pattern was followed by most of the species in the assemblages and similarly observed for species presence and abundance of calling males. The acoustic niche overlap was greater than expected by chance within the assemblages, while no pattern of coincidence or segregation was found for the syntopic congeneric species (Dendropsophus, Boana and Leptodactylus). Moreover, the calling activity of the assemblages, measured as richness and diversity of calling species, was negatively influenced by air and water temperature and positively by relative humidity. Thus, climatic variables act as driver factors to determine calling activity and reproduction of anurans at daily scale. The absence of a segregation pattern at the assembly or genus levels in the calling activity over time indicates that the use of the acoustic temporal niche is not a limiting resource for Cerrado anurans. [ABSTRACT FROM AUTHOR]

Migratory birds occupy different geographical areas during breeding and non‐breeding periods, and thus different factors may determine their range limits depending on each season. One such factor is the spatial climatic component of the niche, which is widely used to model species distributions, yet the temporal component is often neglected and is generally assumed to be constant. We tested the hypothesis that the climatic niche is conserved between breeding and non‐breeding areas in 355 bird species migrating through Eurasian–African flyways. For this, we performed niche overlap analyses and compared niche differences between sister or phylogenetically closely related species, as well as linking the differences to migratory distances. For more than 80% of the species, there was no or very little overlap between their breeding and non‐breeding climatic niches. For most closely related species, the degree of overlap of their breeding climatic niches was larger than the overlap observed within each species, but not for their wintering climatic niches, suggesting a phylogenetic conservation of breeding climatic niches. Finally, there was a clear negative relationship between migratory distances and climatic niche overlap within each species. Our results confirmed that the climatic niche of most Eurasian–African migratory species differs between both breeding and non‐breeding ranges, suggesting distinctive seasonal climatic requirements. Given these results and the geographically uneven effects of climate change, the impact of global change is likely to have different effects in each seasonal range. Hence, both breeding and non‐breeding climatic data need to be considered when using species distribution models. [ABSTRACT FROM AUTHOR]

Migratory birds spend periods of the year in different locations as a response to seasonal changes in environmental suitability. They are classified as either 'niche‐trackers' or 'niche‐switchers', depending on whether they track or switch environmental conditions throughout the year. However, the relationship between these strategies and their migratory behaviour is still unclear. Here we examine whether migratory European Robins Erithacus rubecula and Eurasian Blackcaps Sylvia atricapilla track environmental conditions between breeding and wintering areas and whether their behaviour differs from that of their sedentary counterparts. We used ringing data for both migratory and sedentary individuals wintering sympatrically in the Iberian Peninsula to assess the environmental conditions relating to their seasonal distributions. We explored seasonal niche‐tracking using two multivariate analyses with alternative sets of predictor variables (landscape and climate) to generate different environmental scenarios. Our results show that migratory individuals track similar climatic conditions throughout their seasonal distributions, whereas sedentary birds cope with great variation in climate over the course of the year. In addition, migratory birds show less seasonal overlap in the landscape structure of their chosen habitats compared with sedentary individuals. These results suggest that there is a trade‐off between, on the one hand, the cost for migrants of travelling long distances and, on the other, the increased flexibility required by sedentary birds if they are to tolerate a wider suite of environmental conditions within their permanent ranges. Given that sedentary populations in the southern Iberian Peninsula seem to be linked to populations of migratory individuals of these two species that started to move northwards after the last glacial cycle, the observed patterns suggest that migrant birds represent a fraction of the southern population that is specialized in the exploitation of a narrower range of environmental conditions. [ABSTRACT FROM AUTHOR]

Invasive species may affect the equilibrium of natural communities, competing for resources and occupying niches of the native biota. Dendrocephalus brasiliensis (DEN) has potential to aquaculture, although its use is concerning, since DEN is allochthone in some regions of Brazil. Here, we aimed to study the possible effects of DEN on three cladocerans Moina micrura (MOI), Macrothrix flabelligera (MAC) and Daphnia laevis (DAPH). We performed microcosm experiments combining different cladoceran species in mono- and polycultures in the presence and absence of DEN by evaluating density, biomass, production, stages of development and turnover. MOI was competitive excluded when in 2-species polycultures with MAC and DAPH, and in 4-species polycultures with MAC, DAPH and DEN together. Since MOI survived when cultured with MAC and DAPH in 3-species polycultures, DEN possibly played a role on MOI suppression. Regarding density, DAPH had a slightly suppression when exposed separately with MOI, although MAC had higher production in the presence of MOI. Development stages with similar body size apparently competed more intensely for resources. Our results indicate that DEN has potential to invade ecosystems, destabilizing native zooplankton communities, since it affected MAC and DAPH, thus altering their competitive advantage, besides contributing to MOI exclusion. [ABSTRACT FROM AUTHOR]

The isotopic niche of consumers represents biologically relevant information on resource and habitat use. Several tools have been developed to quantify niche size and overlap. Nonetheless, methods adapted by spatial ecologists to quantify animal home ranges can be modified for use in stable isotope ecology when data are not normally distributed in bivariate space.We offer a tool that draws on existing spatial metrics, such as minimum convex polygon (MCP) and standard ellipse area (SEA), and add novel metrics using kernel utilization density (KUD) estimators to measure isotopic niche size and overlap. We present examples using empirical and simulated data to demonstrate the performance of the package kernel isotopic niches in r (rKIN) under various scenarios.Results of niche size from MCP, SEA and KUD were highly correlated but divergent among datasets. Overall, the KUD method produced the largest niche sizes and was more sensitive to the distribution of the isotopic data. Pairwise estimates of overlap were highly variable, likely because MCP and SEA inherently include or exclude unused areas in the resulting niche estimate. Four bandwidth methods (reference, normal scale, plug‐in and biased cross‐validation) produced comparable estimates of niche size and overlap at various sample sizes (10–40). Niche size and overlap were consistent across sample sizes >15.Use of rKIN will allow isotope ecologists to quantify niche shifts, expansions or contractions, as well as assess the performance of several estimation methods. The package also can be applied to other data types (e.g. principal component analysis, multi‐dimensional scaling) so long as axes and measurement units are identical and can be converted to Cartesian coordinates. [ABSTRACT FROM AUTHOR]

The white‐clawed crayfish (Austropotamobius pallipes) is globally endangered due to the impacts of habitat modification and fragmentation, water pollution, climate change, and invasive species, particularly the signal crayfish (Pacifastacus leniusculus). These pressures have caused the decline of A. pallipes populations in Europe, demonstrating the importance of predicting the species' potential distribution under current and future conditions. Focusing on the watercourses of mainland France, we aimed to identify suitable areas for A. pallipes to guide the conservation of current populations and future introduction actions or protection measures.We applied ecological niche modelling to model the potential distribution of both A. pallipes and P. leniusculus and identified locations suitable for A. pallipes only. We also assessed the potential distribution of the species under two representative concentration pathway (RCP) scenarios: RCP 2.6 and RCP 8.5, respectively describing low‐warming and high‐warming conditions.We found that A. pallipes and P. leniusculus exploit equivalent niches in France. Despite this, under current conditions, about 5% of the study area simultaneously records a high suitability for A. pallipes and a low suitability for P. leniusculus and is therefore of significant conservation interest. This percentage remains relatively stable under RCP 2.6 for 2050 and 2100, but decreases to 2% under RCP 8.5 for 2100.Ecological niche modelling can supply crucial guidance for conservation actions aimed at protecting endangered species at a national scale by identifying sites most suitable for protection and sites where climate change and invasive species constitute a threat. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Understanding predator-prey relationships is fundamental to develop effective conservation plans. Between 2015 and 2018, we combed 21 transects, each 7km long, searching for Iberian Lynx Lynx pardinus scat within the province of Madrid in central Spain. In order to minimise inherent subjectivity of visual identification as much as possible, we performed a double specific nested polymerase chain reaction (PCR) followed by a primer extension assay addressed to two Iberian Lynx diagnostic single nucleotide polymorphisms. Forty-six scat samples were positively identified as belonging to Iberian Lynx through genetic analysis. From these, we extracted remains of consumed prey, which we determined to the lowest possible taxonomic level, mainly through hair identification. Identified prey was divided into four types: lagomorphs, small mammals, birds, and ungulates. The species' diet composition was described based on the frequency of occurrence (FO) of each prey and niche breadth, and also compared with prior knowledge of the species using four prior studies as a comparative reference through the calculation of the niche overlap value. The FO of lagomorphs (39%) was the lowest, while the FO of small mammals (54%) was the highest recorded to date. The niche breath (0.36) was higher than recorded in prior studies, but still showing the specialist character of the Iberian Lynx. Niche overlap was low (C = 0.49), showing differences in trophic niche between the population in our study area and the one studied in southern Spain. This indicates that the Iberian Lynx is adept at switching its main prey, an ability that has previously been firmly rejected. It is, however, capable of adapting to alternative prey more often than recorded to date, which could be a behavioural response to the patchy distribution of European Rabbit Oryctolagus cuniculus in the study area. [ABSTRACT FROM AUTHOR]

What makes some species successful invaders while others fail, and why some invaders have major impacts in invaded ecosystems are pivotal questions that are attracting major research effort. The increasing availability of high resolution, georeferenced stable isotope landscapes ('isoscapes'), coupled with the commercialization of stable isotope‐enriched tracer molecules and the development of new analytical approaches, is facilitating novel applications of stable isotope techniques in ecology. We can now address ecological questions that were previously intractable.We review and discuss how stable isotope analysis (SIA) can complement fundamental research themes in the study of biological invasions, especially in answering questions relating to the physiological and ecological mechanisms underlying invasion processes and invader impacts.SIA was first used for simply describing the diet of invaders but, more recently, SIA‐informed metrics of population and community trophic structure have been advanced. These approaches now permit the comparison of diets across space and time and provide quantitative tools to compare food webs across different stages of invasion.SIA has also been pivotal in quantifying competition for resources between native and non‐native species (e.g. competition for food, water, or nutrient use). Specific questions related to modes of dispersal (e.g. origin and distance/direction travelled) and mechanisms of establishment can also be addressed using SIA in diverse taxa.An overarching goal is to highlight examples of recent studies that have used SIA in key areas of invasion ecology and use these to synthesize testable predictions where SIA could be applied to future studies. We conclude by highlighting several paths forward and describing how unresolved challenges in quantifying the rates, impacts, and mechanisms underlying invasions could potentially benefit from the use of SIA. [ABSTRACT FROM AUTHOR]

The feeding strategy, overlap and trophic interactions of four demersal catfishes inhabiting Cochin Estuary, Arius maculatus (n = 67), A. subrostratus (n = 63), A. arius (n = 21) and Mystus gulio (n = 69) were investigated through gut‐content analyses. The indices of relative importance revealed that the prey items in their stomachs were dominated by crustaceans except in A. arius where molluscs constituted the major prey item. The highest diet and niche breadth values (3.93, 0.36 respectively) were recorded in A. subrostratus, while the lowest was recorded in A. arius (2.64, 0.23 respectively). Pianka's overlap, calculated through null models constructed by Ecosim 7.0, revealed significant niche overlap between A. maculatus and A. subrostratus (O–0.91, P < 0.001), between A. maculatusandM. gulio (O–0.72, P < 0.05) and between A. subrostratusand M.gulio (O–0.64 P < 0.05). However, no overlap was recorded between A. arius and other species. The trophic niche breadth along with prey specific abundance confirmed that these fishes are highly specific feeders. The present results on trophic level status indicate that these catfishes are mid‐level carnivores that can be considered as moderate benthic mesopredators and are specialist feeders unlike most catfishes. [ABSTRACT FROM AUTHOR]

Several attempts have recently been made to elucidate taxonomic status and phylogenetic relationships among the species and subspecies of sand boas of the genus Eryx throughout their distribution range, with no stable consensus about their taxonomy. Here the phylogenetic relationships among the populations of Eryx in Iran and adjacent areas are studied based on two mitochondrial markers (cytb and 16S). Sixteen morphological characters were examined for evaluation of morphological differences among major populations. Ecological niche modeling was applied to demonstrate the potential distribution of the populations in Iran. ENMtools was also used to measure the degree of niche overlap among the major populations in Iran. Based on phylogenetic reconstruction and considering the genetic distances with specimens from type localities, E. tataricus is a junior synonym of E. miliaris and the subspecies rank for E. m. nogaiorum seems to be invalid. Considering the genetic distance of populations in western Iran and Iraq, and the habitat and morphological differences among the populations of Eryx in western Iran, Iraq and Egypt, the population of Eryx in western Iran is suggested as a different species from E. jaculus, named here as Eryx sp. and the ones from Iraq as Eryx cf. jaculus. Here, the evaluation and revision of taxonomic status, distribution ranges and descriptions of morphological characters of the studied species have been done. [ABSTRACT FROM AUTHOR]

Due to the increasing globalisation and ongoing introduction of alien species specifically regarding European freshwater ecosystems, native and already present alien species will be confronted with competitors with unknown outcomes. One such case is the situation of the European catfish Silurus glanis introduced in the Arno River (Central Italy), a species sought after by anglers, which is facing competition from the later introduced alien North American channel catfish Ictalurus punctatus. Large catfish species are highly valued among anglers, but their interspecific interactions and potential ecosystem‐level impacts are still poorly known. We used stomach contents and stable isotope analyses to study niche partitioning between these two alien catfish species, coexisting in the Arno River. The results suggest partial niche segregation, with immature S. glanis showing a narrower dietary and isotopic niche and a slightly higher trophic position than I. punctatus. Monitoring the catfish population sizes, trophic niches and effects on lower trophic levels are essential for future management and mitigation of their potential impacts on invaded freshwater ecosystems. [ABSTRACT FROM AUTHOR]

Meliponinae eusocial bees are among the most important pollinators in the Neotropics and their beekeeping has been growing as both recreational and economic activity. Information on the pollen preferences and niche overlap among species coexisting in the same location is still scarce. This study focused on the use of pollen resources by three native species of Meliponinae in the Atlantic Forest, Melipona quadrifasciata quadrifasciata (Lepeletier 1836), Scaptotrigona depilis (Moure 1942), and Tetragonisca angustula (Latreille 1811), at two different sites. The use of pollen resources was evaluated from reserves inside hives collected monthly between February 2015 and January 2016. It was also estimated the Mean Minimal Distance (Dm) traveled by the bees to obtain pollen. The bees differed regarding the diversity of pollen types, Dm, and proportion of pollen from different plant life-form. Local factor promoted differences only for Dm. M. q. quadrifasciata foraged a low diversity of pollen species and traveled greater distances with a higher proportion of trees plus palm species. Tetragonisca angustula foraged a higher diversity of pollen and flew shorter distances with a lower proportion of trees and palms. The species factor predominates over the local factor in the clustering pattern, based on pollen profile similarity. [ABSTRACT FROM AUTHOR]

• Niche modeling using the SoilGrids database is a valuable tool in ecological studies. • Tetraploids have a wider niche breadth when compared to diploids. • Polyploidization under changing environmental conditions leads to colonization. • Festuca amethystina extended the geographical range to post-glacial lowland areas. • The soil factor can be key in plant distribution. In the framework of polyploidization, a widely discussed issue is the possibility of niche shift. Numerous studies have investigated niche differentiation among cytotypes, with some confirming distinct differences, while others finding them to be similar. Within this research project, we focus on the case of the cytotypes (2x and 4x) of Festuca amethystina L. and the closely related F. tatrae (Czakó) Degen (2x). We hypothesize that a significant change in the edaphic niche of tetraploids could be a factor that enabled them to occupy new lowland areas inaccessible to diploids which are characteristic of mountain habitats. The edaphic niche differentiation between Festuca amethystina cytotypes was determined by studying the niches' breadths using PCA-based modeling and separate analyses of particular soil features. The modeling was based on SoilGridsTM data, and the conclusions were compared with the results of the direct soil studies. Such a research model makes it possible to determine to what extent the data coming from the mentioned database allows for the indication of niche differentiation. Coarse-grained modeling based on SoilGridsTM data indicated a significant change in the edaphic requirements of the tetraploids, as well as pointed to the niche shift towards a higher content of sand, lower carbon and nitrogen content, and lower pH. The direct soil sampling and laboratory tests confirmed these trends and provided a more detailed understanding of the cytotypes requirements. However, no statistically significant differences were observed between cytotypes concerning soil pH, the majority of base cations, available forms of phosphorus and potassium, and the results of CHN elemental analysis. While the direct soil sampling did not reveal significant differences, the analyses based on the niche modeling, considering a wide background area in Central Europe (using SoilGrids data), captured significant variations. This comprehensive approach allowed us to uncover a highly logical pattern of niche shift, which indicates that tetraploids are predisposed to extend their geographical range to post-glacial lowland areas. Additionally, Festuca amethystina tetraploids display a wider edaphic niche breadth than their closely related and hypothetical ancestor Festuca tatrae. The decision to include the latter reduced the probability that the obtained result of the significant increase of the tetraploid edaphic niche was a simple result of hybridization. [ABSTRACT FROM AUTHOR]

Every year, the Coastal wetlands of North Africa support an important wintering waterbird population of many Palearctic and sub-Saharan species of various contrasting habitat requirements. In this study, we describe the habitat use by24 water-obligate species wintering in a coastal wetland of the Northeastern Algeria (the wetland of Lake Tonga), highlighting thereby the ecological mechanisms that support their coexistence and their resources partitioning. The analysis of resource exploitation (Relative frequency, Feinsinger niche breadth, Pianka niche overlap and Ivlev’s electivity indexes) showed that waterbird species inhabiting the lake wetland have several similarities in using the different habitat categories, which lead us to cluster them into 5 guilds (G1: one rails, two grebes and eight ducks; G2: five wading species and one gull; G3: three herons; G4: cormorants, mallards, and on gull; finally, G5: only one species Cattle egret (Bubulcus ibis).Almost all the species were specialists in resource utilization patterns (narrow niche breadths, both under 0.3) and therefore, vulnerable to fluctuations in resources, particularly the feeding habitats. Mean niche overlaps for all the pairs of species ranged from 0.05 to 0.68. The overall pattern in the community was higher niche overlaps between the species of a particular guild than those between other species. According to Ivlev’s electivity index, we found that only three microhabitats from seven were the most important for the discussed species, open water body was the most attractive, followed by meadows, muddy areas and floating- leafed vegetation. Similarities on habitat requirements derived from our region can provide important and optimal wetland management at multi-species assemblage level for this wetland and similar area around the African coast.

Abstract: The objective of this work was to estimate an index of the relative biomass per species, in a medium to large-sized mammal community, as well as to determine how the introduced wild boar (Sus scrofa) fits into this index, and to verify if the occupancy of sites by domestic dogs interferes with those of wild boars and how much the periods of dogs’ activity overlap those of wild boars. The biomass/effort index was measured for each native mammal species and for the introduced wild boar, in two surveyed farms in Brazil’s Western Atlantic Forest range, through the use of camera trappings that were also used to verify if dogs and wild boar overlap in space and activity time. Wild boars seem to dominate the community, just a few years after their presence was first recorded in the region. Surprisingly, several native endangered mammal species persist in the highly modified landscape of the studied areas, but their population trends are still unknown. Wild boars and dogs generally occupy the same areas; however, they do not overlap in activity time, which is an indicative that it is unlikely that the dogs can effectively protect the crops.

Three species belonging to the genus Dermacentor (Acari: Ixodidae), D. marginatus, D. nuttalli and D. silvarum are well known as vectors for a great variety of infection pathogens. All three of them are host ticks, which are very similar in morphology characteristics, life cycle, seasonal variation and ecological conditions, making it difficult to distinguish the three species. In the present study, these three species were delimitated based on molecular data and ecological niche. The molecular analysis showed that the three species can be distinguished by COI and ITS2 sequences. We created future potential distribution maps for the three species under climate changes with MaxEnt, which highlighted the different levels of the suitable habitats for each tick species. In addition, niche comparisons among the three species in Dermacentor were conducted, and the analysis suggested that niche overlap was relatively high with D. nuttalli and D. silvarum compared to the other species pairs, which was consistent with the molecular data. Niche equivalency and similarity test confirmed that these Dermacentor species were closely related but distinct species. In conclusion, delimitation of these three species within Dermacentor was supported by molecular phylogeny and quantitative ecological space. This study will provide deep insights into the biology, ecology, and diversification processes within Dermacentor species, and for the development of effective control for ticks.

Alpine wetland degradation threatens riparian biodiversity and ecological balance. Our study, conducted in July 2020 along the northern and eastern shores of Qinghai Lake, seeks to unravel the impacts of such degradation on plant species dominance and ecological niches, using advanced network analysis methods to explore the dynamics and survival strategies of plant species. We applied a space-to-time method to delineate three wetland degradation stage: a healthy swamp wetland, a slightly degraded wet meadow, and a degraded dry meadow. Six representative sampling points were chosen. At each point, three sample lines were randomly established, radiating outward from the center of the lake wetland, with each stage of degradation meticulously examined through three replicates to assess the plant communities in terms of species composition, plant height, coverage, and abundance. The results indicated: Species such as Kobresia tibetica and Leymus secalinus exhibit remarkable abundance across various stages of wetland degradation, indicating a robust tolerance to these conditions. This observation, coupled with the complexity of plant community structures in degrading wetlands, suggests that such intricacy cannot be solely attributed to the dominance of particular species. Instead, it is the result of a diverse array of species adapting to fluctuating water levels, which promotes increased species richness. Despite the prominence of species that exhibit rapid growth and reproduction, the ecological significance of less abundant species in contributing to the community's complexity is also notable. Changes in habitat conditions due to wetland degradation facilitate both competitive and cooperative interactions among species, highlighting the dynamic nature of these ecosystems. Our analysis shows no significant linear relationship between the ecological niche overlap values and niche widths of plant species. However, the strategies employed by dominant species for competition and resource acquisition, as observed in the ecological niche overlap networks, underscore the adaptive capacity of plant communities. These insights underscore the need for tailored restoration strategies to conserve the biodiversity of alpine lake riparian ecosystems. This research not only sheds light on the resilience and adaptability of ecosystems in the Qinghai-Tibetan Plateau but also offers valuable lessons for the conservation of similar habitats worldwide. Our findings underscore the need for tailored restoration strategies to conserve the biodiversity of alpine lake riparian ecosystems. This research not only sheds light on the resilience and adaptability of ecosystems in the Qinghai-Tibetan Plateau but also offers valuable lessons for the conservation of similar habitats worldwide., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wu, Dong, Wang, Li, Ma and Li.)

The relationship between spatial distribution and phylogeny has been widely debated in recent decades. To understand biogeographic and evolutionary history relationships and to explore the interspecific similarities and phylogenetic correlations of niche characteristics, we collected and recorded all distribution points for eight species of rhubarb on the Qinghai-Tibet Plateau, used different methods to describe the ecological niche, and explored the relationship between phylogeny, ecological niche, and distribution range. The results reveal that: (1) the ranges of optimal environmental variables for species with close kinship are not exactly the same, ecologically similar species are not necessarily sister species, and the overlap of rhubarb has no significant correlation with phylogeny. Therefore, the impact of ecological dimensions on species formation is greater than that of geographical latitude for the eight species of rhubarb. (2) Among the eight species of rhubarb, the breadth of ecological niche is positively correlated with the current suitable habitat area and negatively correlated with fluctuations in future suitable habitat area. In the future, except for Rheum tanguticum and Rheum palmatum , the suitable planting areas for the other six species of rhubarb will decrease as greenhouse gas emissions concentrations and time increase. Therefore, species with smaller ecological niches are at a greater risk of habitat loss compared to species with larger ecological niches. (3) In both existing and future distribution prediction models of rhubarb, we observed that both the widely distributed Rheum spiciforme and the niche narrow Rheum nobile , all eight species of rhubarb are present in the Hengduan Mountains, based on our analysis, we propose that the Hengduan Mountains should be regarded as a priority conservation area for rhubarb, to preserve the species' biodiversity. Our study lays the groundwork for identifying evolutionary trends in ecological specialization., Competing Interests: The authors declare that they have no known competing financial, interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)

By integrating species distribution modeling techniques, phylogenetic comparative methods, and climatic data, we analyzed how European falcon climatic niches have changed over evolutionary time in order to understand their tempo and mode of evolution and gain phylogenetic insights related to the ecological context of falcon evolution. For this purpose, we tested the relative contributions of niche conservatism, convergent evolution, and divergent evolution in the evolutionary history of this group of species in Europe. The occupation of climatic niche spaces by falcon species in Europe was not similar, considering that their climatic niche evolution was characterized by heterotachy, especially after ca. 4 Mya. Our results indicate that convergent evolution and niche divergence played an important role in the evolutionary history of these species, with no significant evidence of closely related species retaining their fundamental niche over time (phylogenetic niche conservatism). In most analyses, less closely related falcon species occupied similar climatic environments. We found that speciation in the European genus Falco was influenced by climatic niche differentiation, more prevalent in the last 4 million years, with the main climatic niche shifts occurring between closely related falcon species.

The plant pathogenic fungus Cytospora is notoriously known for causing woody plant canker diseases, resulting in substantial economic losses to biological forests and fruit trees worldwide. Despite their strong negative ecological impact, the existing and prospective distribution patterns of these plant pathogens in China, according to climate change, have received little attention. In this study, we chose three widely dispersed and seriously damaging species, namely, Cytospora chrysosperma , Cytospora mali , and Cytospora nivea , which are the most common species that damage the Juglans regia , Malus domestica , Eucalyptus , Pyrus sinkiangensis , Populus spp., and Salix spp. in China. We utilized ecological niche modeling to forecast their regional distribution in China under four climate change scenarios (present, SSP 126, SSP 370, and SSP 585). The results show that temperature-related climate factors limit the current distribution ranges of the three species. Currently, the three studied species are highly suitable for northeast, northwest, north, and southwest China. Under future climate scenarios, the distribution ranges of the three species are projected to increase, and the centers of the adequate distribution areas of the three species are expected to shift to high-latitude regions. The three species coexist in China, primarily in the northwest and north regions. The ecological niches of C. chrysosperma and C. nivea are more similar. The distribution range of C. mali can reach the warmer and wetter eastern region, whereas C. chrysosperma and C. nivea are primarily found in drought-prone areas with little rainfall. Our findings can help farmers and planners develop methods to avoid the spread of Cytospora spp. and calculate the costs of applying pesticides to reduce contamination and boost yields.

Understanding species distributions and predicting future range shifts requires considering all relevant abiotic factors and biotic interactions. Resource competition has received the most attention, but reproductive interference is another widespread biotic interaction that could influence species ranges. Rubyspot damselflies (Hetaerina spp.) exhibit a biogeographic pattern consistent with the hypothesis that reproductive interference has limited range expansion. Here, we use ecological niche models to evaluate whether this pattern could have instead been caused by niche differentiation. We found evidence for climatic niche differentiation, but the species that encounters the least reproductive interference has one of the narrowest and most peripheral niches. These findings strengthen the case that reproductive interference has limited range expansion and also provide a counterexample to the idea that release from negative species interactions triggers niche expansion. We propose that release from reproductive interference enables species to expand in range while specializing on the habitats most suitable for breeding., (© 2023 The Authors. Ecology Letters published by John Wiley & Sons Ltd.)

We investigated the importance of ecological and historical effects in structuring a lizard assemblage in a semiarid area of Caatinga habitat. We collected lizards using pitfall traps and active searching; we also collected data concerning microhabitat and diet composition for the lizard species examined. We used null models to test whether or not the community was structured following microhabitat or trophic niches. We also tested whether or not such structure had a historical or ecological origin using canonical phylogenetic ordination and phylogenetic principal component analysis. Gymnodactylus geckoides and Tropidurus hispidus were most generalized in their microhabitat use. Hemidactylus brasilianus and Phyllopezus pollicaris had the greatest numeric niche breadth, whereas P. pollicaris and T. hispidus had the greatest volumetric niche breadth. In contrast, Brasiliscincus heathi and Ameiva ameiva had the smallest numeric and volumetric niche breadths, respectively. The lizard assemblage examined had structure in both microhabitat and trophic niches. We detected phylogenetic conservatism on the basis of spatial niches in the clades Teoidea, Teiidae, and Tropiduridae. In contrast to the predictions of the niche complementarity hypothesis, we found high trophic overlap coupled with low microhabitat overlap for tropidurids. Moreover, spatial niche structure was mainly attributable to historical factors (phylogenetic), whereas ecological factors were more important determinants of trophic niche structure. [ABSTRACT FROM AUTHOR]