Ecology and Evolution最新文献

Predation plays an important role in animal evolution by selecting for antipredator adaptations. Antipredator color adaptations include conspicuous spots, which are believed to provide protection by deflecting attacks to harmful or peripheral body parts, deimatic signaling, or as conspicuous warning coloration. The utility of antipredator signals is context-dependent and may be influenced by the environment. In this study, we investigated the selective forces acting on the evolution of conspicuous spots on velvet ants (Mutillidae: Dasymutilla). We tested whether conspicuous spots in 80 species of velvet ants evolved in (i) forest-dwelling species, (ii) habitat-generalist species, or (iii) species predated by diverse birds and frogs. Results show that conspicuous spots are more likely to evolve in forest-dwelling species and in areas with more canopy cover, whereas species inhabiting open areas and deserts tend to lose them. Moreover, taxa with conspicuous spots transition between open and forested habitats less often. Spot presence was not associated with predator diversity. We suggest that spots in velvet ants require complex visual environments to be effective, which may limit their habitat occurrence. In simpler environments, carrying conspicuous spots could be costly due to increased exposure to visual predators.

Gut microbiota crucially affects metabolism and health. Hycleus cichorii Linnaeus has been listed as a medicinal insect in the Pharmacopeia of the People's Republic of China due to the presence of cantharidin, which has a curative effect on many cancers and skin diseases. In order to analyze the effects of dietary habits and gender on the diversity and composition of gut microbiota in H. cichorii and provide a basis for an artificial diet, in this study, the full-length 16S rRNA sequencing technology was used to analyze the gut microbiota of 35 H. cichorii adults, including wild female adults (WFA), wild male adults (WMA), female adults fed with luffa flowers (LFA), male adults fed with luffa flowers (LMA), female adults fed with artificial diet (AFA), and male adults fed with artificial diet (AMA). The results displayed that the major bacterial phyla present in the gut microbiota of the H. cichorii were Firmicutes, Proteobacteria, Bacteroidetes, Fusobacteria, Teneriicutes, and Actinobacteria. The major bacterial genera were Lactococcus, Lactobacillus, Enterococcus, Ralstonia, Sebaldella, Dysgonomonas, Spiroplasma, Weissella, Klebsiella, and Serratia. Food habits had a significant effect on the diversity and composition of gut microbiota in H. cichorii, whereas gender did not exhibit a remarkable impact on the diversity and composition of gut microbiota. The artificially fed group of H. cichorii had more beneficial microorganisms in the intestine and higher food utilization efficiency. These results provide a basis for subsequent examination of gut microbiota in H. cichorii or other Coleoptera insects, as well as the artificial rearing of blister beetles.

Global change models predict not only a steady increase in temperatures but also an increase in the occurrence of hot and cold extremes. Organisms' responses to thermal extremes will depend on species-specific traits and the degree of within-species variation (among populations), with populations from warmer latitudes often predicted to have higher thermal tolerance than populations from colder latitudes. The evolution of population-specific responses, however, can be limited by gene flow that homogenises populations. Here, we investigate this relationship with a study of the survival of Littorina littorea, L. obtusata, and L. saxatilis—marine snails with varying dispersal potential—collected on either side of a known biogeographic break. Snails were laboratory-acclimated for several weeks before undergoing exposures to extreme heat, extreme cold, or ambient conditions, and individual mortality was recorded after each exposure. In line with common predictions, we observed that the degree of population divergence in survival under thermal extremes was negatively related to dispersal potential, and that populations from the colder latitude generally had higher survival of sub-freezing temperatures. Contrary to common predictions, however, we observed greater survival after extreme heat in populations from colder latitudes than in their warmer-latitude counterparts, a pattern known as countergradient variation. This experiment highlights counterintuitive responses to thermal extremes, emphasising that colder-latitude populations could experience population growth under more extreme climates due to higher survival at both hot and sub-freezing thermal extremes.

Delavaux, C. S., A. Aellen, S. L. Stürmer, et al. 2025. “Uncovering Diversity Within the Glomeromycota: Novel Clades, Family Distributions, and Land Use Sensitivity.” Ecology and Evolution 15: e70597. https://doi.org/10.1002/ece3.70597.

The author name “Silmar Primier” should be changed to “Silmar Primieri.” The online version of this article has been corrected accordingly.

We apologize for this error.

We re-examined reports of hybridisation in three cryptic stingless bee species in the genus Tetragonula in South East Queensland, Australia (T. carbonaria, T. davenporti and T. hockingsi). Previous studies on this group using microsatellite markers proposed that hybridisation occasionally takes place. In contrast, we find that using 1745 SNPs we could reliably separate the three species, with no evidence of contemporary (or recent) hybridisation. We found identical amplicon sequences of the nuclear gene EF1alpha across most individuals of the three species, but low and moderate species-specific polymorphisms in the nuclear gene Opsin and the mitochondrial 16S rRNA gene, respectively, with no cases of mito-nuclear discordance at these genes. We confirm that nuclear divergence across these species is low, based on 10–26 kb of non-coding sequence flanking EF1alpha and Opsin (0.7%–1% pairwise difference between species). However, we find mitogenomes to be far more diverged than nuclear genomes (21.6%–23.6% pairwise difference between species). Based on these comprehensive analyses of multiple marker types, we conclude there is no ongoing gene flow among the Tetragonula species of South East Queensland, despite their morphological similarity to one another and the low nuclear divergence among them. The higher resolution provided by multiple SNP markers may lead to lower estimates of contemporary hybridisation more generally.

Large-scale anthropogenic developments in the metropolitan areas of Nepal and the rural to urban influx of people have exacerbated human–wildlife conflicts across human-altered landscapes of Nepal. The Kathmandu Valley has experienced large-scale urbanization and has subsequently witnessed substantial incidents of human–wildlife conflicts given the increasing levels of human encroachment into remnant wildlife habitats. Here, we applied DNA metabarcoding in combination with geospatial analysis to study the feeding ecology of two urban carnivores, the leopard (Panthera pardus) and the leopard cat (Prionailurus bengalensis), in the forests surrounding the Kathmandu Valley and to check whether the leopards' predation on domestic animals contributes to human-leopard conflict in this region and to obtain a baseline data on the dietary habits of the poorly studied leopard cat. We found that leopards were highly dependent on domestic animals in areas dominated by human-use activities (agricultural and built-up areas), whereas leopard cats mostly predated on wild rodents. Through our work, we highlight the importance of domestic prey in the diets of urban carnivores like leopards and demonstrate the influence human-induced habitat disturbance has on the ecology of local wildlife. This study generates critical information which will help to inform conflict mitigation strategies and conservation planning for the two carnivore species, in addition to identifying areas within the region that are susceptible to human–wildlife conflicts.

Faecal cortisol/corticosterone metabolites (FCMs) have become increasingly popular as an easy-to-sample, non-invasive and feedback-free alternative to assess glucocorticoid (GC) levels, key components of the neuroendocrine stress response and other physiological processes. While FCMs can be a powerful aid, for instance, for gaining insights into ecological and evolutionary processes, as well as to assess animal welfare or impacts of anthropogenic stressors on wildlife populations, this method comes with specific challenges. Because GCs are heavily metabolised before excretion, it is critical to validate the enzyme immunoassays (EIAs) used to measure FCMs. Additionally, because species may differ in metabolite profiles, assay validation must be performed separately for each focal species. Despite this, the use of unvalidated assays remains widespread. We performed a biological validation experiment to test a set of EIAs to measure FCMs and adrenocortical activity in free-living Alpine marmots Marmot marmota. We capitalised on capture and handling as part of a relocation project of marmots under the assumption that capture, and handling represent a stressful event and tracked changes in FCM levels over the following 48 h. Faeces samples collected at capture were assumed to return baseline FCM levels. Of the three EIAs tested, only the 11-oxoetiocholanolone ‘72T’ EIA detected an increase in FCM levels about 18 h after capture. This result paves the way for future studies using FCMs to investigate the adrenocortical activity in this species.

Herons (Ardeidae), an important group in wetland ecosystems, have a particularly strong relationship with humans. However, their predation on farmed fish and shrimp in aquafarms can lead to economic losses for local fish farmers. Consequently, notable conflicts arise between fish farmers and herons. Fish farmers adopt various measures to deter herons from “stealing” their fish; however, there is limited research on the behavioral responses of herons under such pressures of human disturbance. Flight initiation distance (FID) is an important manifestation of avian anti-predation behavior and serves as an indicator of birds' tolerance to human disturbance. This study investigated the potential variations in tolerance to human disturbance between the little egret (Egretta garzetta) and the Chinese pond heron (Ardeola bacchus) in “stealing” environments (aquafarm environments) and non-aquafarm environments in Hainan and Guangdong Provinces, south China, using FID as an indicator. Herons in aquafarm environments were less tolerant (having longer FIDs) to human disturbance compared to herons in non-aquafarm environments. The main cause of this phenomenon could be the harsh deterrents used by humans to prevent herons from “stealing” fish. These deterrents increase the predation risk for herons when “stealing” in aquafarms, causing them to exhibit less tolerance to human disturbance. Our study increases understanding of the behavioral response patterns of herons in human–wildlife conflicts and provides valuable insights for more scientific and rational management and protection of Ardeidae species.

Traditionally managed grasslands are among the most species-rich communities, which are threatened by land use changes—management intensification or abandonment. The resistance of their species composition to mismanagement and ability to recover after re-establishment of traditional management is of prime conservational interest. In a manipulative experiment in a wet meadow, we simulated mismanagement by a factorial combination of abandonment of mowing and fertilization. The dominant species Molinia caerulea was removed in half of the plots to assess its role in community dynamics. The 21 years' mismanagement period was followed by the re-establishment of the traditional management. The plots were sampled yearly from 1994 (the baseline data, before the introduction of the experimental treatments), until 2023. Estimates of cover of all vascular plant species provided the species richness and effective number of species. For each year, the chord distances to baseline species composition and to corresponding control plot were calculated. The compositional data were analyzed by constrained ordination methods, and the univariate characteristics by Repeated Measures ANOVA. All the plots, including those with traditional management throughout the whole experiment, underwent directional changes, probably caused by a decrease in groundwater level due to global warming. Both fertilization and abandonment led to a loss of competitively weak, usually low-statured species, due to increased asymmetric competition for light. The effect of fertilization was faster and stronger than that of abandonment demonstrating weaker resistance to fertilization. The removal of dominant species partially mitigated negative effects only in unmown, non-fertilized plots. The recovery following mismanagement cessation was faster (signifying higher resilience) in unmown than in fertilized plots, where it was slowed by a legacy of fertilization. In a changing world, two reference plot types are recommended for assessment of resistance and resilience, one original state and one reflecting compositional changes independent of treatments.

In some animals, males use colorful ornaments or badges to visually communicate with conspecifics. These traits can be condition-dependent, suggesting that environmental changes could impact the intensity of male sexual signals. Drastic habitat changes caused by urbanization can act as physiological stressors, potentially affecting male signaling traits through changes to condition or immune function. Here, we quantified the effects of urbanization on ventral patch size and correlates of patch expression, namely body size, body condition, corticosterone concentrations, and ectoparasites in male Western Fence Lizards (Sceloporus occidentalis). We compared three aspects of male ventral color patches between urban and natural populations: area of the throat patch, total area of the paired belly patches, and total area of the black borders of the belly patches. All three area measurements across both habitat types were positively related to body size, and total belly patch area was positively related to body condition, indicating that these traits may signal male competitive ability and/or quality. Males from urban populations had larger throat patches than those from natural populations after controlling for body size. This difference in patch size was associated with a difference in probability of ectoparasite infection, but not with differences in corticosterone concentrations or body condition between urban and natural populations. Our results may indicate an effect of urbanization on immune function affecting male patch expression, although this idea remains untested. Overall, we show that urbanization can impact male sexual traits, which may have repercussions for visual communication in urban environments.