Body size shifts in ectotherms are mostly attributed to the Temperature Size Rule stating that warming speeds up initial growth rate but leads to smaller size when food availability does not limit growth. Nevertheless, climate warming can decrease food availability, which can influence growth, fecundity and survival. However, the interactive effects of temperature and food availability on life history traits have been mostly studied in small invertebrate species. In contrast, we have limited information on how temperature and food availability jointly influence life history traits in vertebrate predators and how changes in different life history traits combines to influence population demography. We investigated the independent and interactive effects of temperature and food availability on traits of the medaka fish Oryzias latipes. We used our empirical estimates of vital rates as input parameters of an Integral Projection model to predict how modifications in vital rates translate into population demography. Our results confirm that warming leads to a higher initial growth rate and lower size leading to crossed growth curves between the two temperatures. Food-restricted fish were smaller than ad libitum fed fish throughout the experiment. Fish reared at 30 °C matured younger, had smaller size at maturity, had a higher fecundity but had a shorter life span than fish reared at 20 °C. Food restriction increased survival under both temperature conditions. Warming reduces generation time and increases mean fitness in comparison to the cold treatments. Food restriction increased generation time and fitness in the cold treatment but had no effect in the warm treatment. Our results highlight the importance of accounting for the interaction between temperature and food availability to understand how body size shifts can affects vital rates and population demography. This is of importance in the context of global warming as resources are predicted to change with increasing temperatures.

Many symbionts are sexually transmitted and impact their host’s development, ecology, and evolution. While the significance of symbionts that cause sexually transmitted diseases (STDs) is relatively well understood, the prevalence and potential significance of the sexual transmission of beneficial symbionts remain elusive. Here, we study the effects of sexually transmitted mutualist nematodes on their dung beetle hosts. Symbiotic Diplogastrellus monhysteroides nematodes are present on the genitalia of male and female Onthophagus beetles and are horizontally transmitted during mating and vertically passed on to offspring during oviposition. A previous study indicates that the presence of nematodes benefits larval development and life history in a single host species, Onthophagus taurus. However, Diplogastrellus nematodes can be found in association with a variety of beetle species. Here, we replicate these previous experiments, assess whether the beneficial effects extend to other host species, and test whether nematode-mediated effects differ between male and female hosts. Rearing three distantly related dung beetle species with and without nematodes, we find that the presence of nematodes benefits body size, but not development time or survival across all three species. Likewise, we found no difference in the benefit of nematodes to male compared to female beetles. These findings highlight the role of sexually transmitted mutualists in the evolution and ecology of dung beetles. Furthermore, these results suggest a potential new avenue through which environmental pollution with veterinary deworming agents may affect dung beetles and their ecosystem services.

Climate change impacts are driving forest fires worldwide and reducing snowfall in temperate countries. Whether these impacts result in a significant alteration of winter soil respiration (Rs) rates and temperature in the postfire and the undisturbed black pine (Pinus nigra) forests remain poorly understood. A field experiment was conducted in the postfire and the undisturbed black pine forests during a winter period in Türkiye to quantify Rs rates as affected by lack of snow and snow cover. Four treatments were applied: snow-exclusion postfire (SEPF), snow postfire (SPF), snow-exclusion undisturbed forest (SEUF), and snow-undisturbed forest (SUF). The SEPF exhibited the significantly lowest mean Rs rates (0.71 µmol m-2 s-1) compared to the SPF (1.02 µmol m-2 s-1), SEUF (1.44 µmol m-2 s-1, and SUF (1.48 µmol m-2 s-1). The Rs also showed significant variations with time (p <.0001). However, treatments and time exhibited no statistically significant interaction effects (p = 0.6801). Total amounts of winter Rs (January to March) ranged from 4.92 to 5.07 Mt CO2 ha-1 in the undisturbed forest and 2.53 to 3.51 Mt CO2 ha-2 in the postfire site. The Rs showed a significantly positive relationship (p <.0001) with the soil (0.59) and air (0.46) temperatures and a significantly negative relationship (p = 0.0017) with the soil moisture (-0.20) at the 5 cm depth. In contrast, the Rs showed a negative, but not statistically significant relationship (p = 0.0932) with the soil moisture (-0.16) at the 10 cm soil depth. The combined effects of lack of snow and forest fire resulted in a significant decrease of Rs. In contrast, a warmer winter significantly increased Rs rates in the undisturbed forest, suggesting that a warmer winter could potentially accelerate soil organic carbon losses in naturally growing undisturbed forest ecosystems, thus, providing positive feed backs to climate change.

Freshwater ecosystems are increasingly affected by rising annual mean temperatures and extreme heatwaves. While heatwaves are expected to have more immediate effects than mean temperature increases on local communities, comparative experimental studies are largely lacking. We conducted a one-month mesocosm experiment to test the effect of different warming scenarios, constantly raised temperatures (+3°C), and recurring heatwaves (+6°C) on plankton communities. We specifically tested how shifts in zooplankton trait composition and functional groups are reflected in ecosystem functioning (top-down control on primary producers). We found that heatwaves had a stronger and more immediate effect on trait and functional group compositions. Heatwaves were associated with larger body sizes, and the decrease in micrograzers resulted in weaker top-down control, leading to elevated algal biomass. Altogether, our results highlight the importance of the indirect effects of heatwaves via inducing shifts in zooplankton functional groups and trait composition which may foster periodic algal blooms.

Since the analysis of animal behavior is a central element of ethology and ecology, it is not surprising that a great deal of research has been conducted describing the behavior of various ungulates. Most studies were conducted during the daylight hours, thus much less is known about nocturnal behavior. Detailed analyses of nocturnal behavior have only been conducted for very prominent ungulates such as giraffes, elephants, or livestock, and the nocturnal rhythms exhibited by many ungulates remain unknown. In the present study, the nocturnal rhythms of 192 individuals of 18 ungulate species from 20 European zoos are studied with respect to the behavioral positions standing, lying - head up, and lying - head down (the typical REM sleep position). Differences between species of the orders Perissodactyla and Cetartiodactyla, as well as between individuals of different age were found. However, no differences with respect to the sex were seen. Most species showed a significant increase in the proportion of lying during the night. In addition, the time between two events of “lying down” was studied in detail. A high degree of rhythmicity with respect to this quantity was found in all species. The proportion of lying in such a period was greater in Cetartidactyla than in Perissodactyla, and greater in juveniles than in adults.

Climate suitability analyses based on ecological niche modeling provide a powerful tool for biological control practitioners to assess the likelihood of establishment of different candidate agents prior to their introduction in the field. These same analyses could also be performed to understand why some agents establish more easily than others. The release of three strains of Aphalara itadori (Shinji) (Hemiptera: Pysllidae), each from a different source locality in Japan, for the biological control of invasive knotweed species, Reynoutria spp. Houtt. (Caryophyllales: Polygonaceae), provides an important opportunity to compare the utility of climate suitability analyses for identifying potential climate-based limitations for successful biological control introductions. Here we predict climate suitability envelopes for three target species of knotweed in Europe and two target species of knotweed in North America and compare these suitability estimates for each of these species to the source localities of each A. itadori strain. We find that source locality of one strain, the Kyushu strain, has little-to-no suitability compared to other locations in Japan based on knotweed records from Europe, supporting an earlier study based on North American Japanese knotweed records. The source locality of a second strain, the Murakami strain, was predicted to have medium-to-high suitability based on records of knotweeds from North America. In contrast, European records of R.  bohemica Chrtek & Chrtková and R. sachalinensis (F. Schmidt) Nakai predicted no suitability for this locality compared to other locations in Japan, while European records for R. japonica Houtt. predicted low suitability. The source locality of the final strain, the Hokkaido strain, was predicted as having medium-to-high suitability based on knotweed records of all examined species from both North America and Europe.

As an island endemic with a decreasing population, the Critically Endangered Grenada Dove Leptotila wellsi is threatened by accelerated loss of genetic diversity resulting from ongoing habitat fragmentation. Small, threatened populations are difficult to sample directly but advances in molecular methods mean that non-invasive samples can be used. We performed the first assessment of genetic diversity of populations of Grenada Dove by a) assessing mtDNA genetic diversity in the only two areas of occupancy on Grenada, b) defining the number of haplotypes present at each site and c) evaluating evidence of isolation between sites. We used non-invasively collected samples from two locations: Mt Hartman (n=18) and Perseverance (n=12). DNA extraction and PCR were used to amplify 1,751 bps of mtDNA from two mitochondrial markers: NADH dehydrogenase 2 (ND2) and Cytochrome b (Cyt b). Haplotype diversity (h) of 0.4, a nucleotide diversity (π) of 0.4 and two unique haplotypes were identified within the ND2 sequences; one haplotype was identified within the Cyt b sequences. Of the two haplotypes identified; the most common haplotype (haplotype A = 73.9%) was observed at both sites and the other (haplotype B = 26.1%) was unique to Perseverance. Our results show low mitochondrial genetic diversity, a non-expanding population and clear evidence for genetically isolated populations. The Grenada Dove needs urgent conservation action, including habitat protection and potentially augmentation of gene flow by translocation in order to increase genetic resilience and diversity with the ultimate aim of securing the long-term survival of this Critically Endangered species.

The nests of ground-nesting birds rely heavily on camouflage for their survival, and predation pressures, often linked to human activity, are a major source of mortality. Numerous ground-nesting bird populations are in decline, so understanding the effects of camouflage on their nesting behaviour is of relevance to their conservation concern. Habitat three-dimensional (3D) geometry together with predator visual abilities, viewing distance, and viewing angle determine whether a nest is either visible, occluded or too far away to detect. While this link is intuitive, few studies have investigated how fine-scale geometry is likely to help defend nests from different predator guilds. We quantified nest visibility based on 3D occlusion, camouflage, and predator visual modelling in northern lapwing, Vanellus Vanellus, on different land management regimes. Lapwings selected local backgrounds that had a higher 3D complexity at a spatial scale greater than their entire clutches compared to nearby control sites. Importantly, our findings show that habitat geometry – rather than predator visual acuity restricts nest visibility to terrestrial predators, and that an open field would actually be perceived as a closed habitat to a terrestrial predator searching for nests on the ground. Taken together with lapwings’ careful nest site selection, our findings highlight the importance of considering habitat geometry for understanding the evolutionary ecology and management of conservation sites for ground-nesting birds.

1. Temperature is essential for the survival and development of eggs. Some anurans have evolved and developed foam nesting traits, with thermal insulation considered to be among their functions. Foam nesting frogs tend to exhibit reproductive plasticity. For example, they oviposit on both trees and the ground. How such plasticity affects foam nest function is of major relevance and is likely related to the adaptation of foam nesting frogs. However, this has not been well studied. 2. In this study, we studied the interaction between foam nest site, foam nest function, and egg fate using the Japanese green tree frog, Zhangixalus arboreus, and analysed how nest site differences (arboreal or terrestrial) affect the thermal function of foam nests. 3. We compared the thermal functions of foam nests between arboreal and terrestrial oviposition sites of Z. arboreus. We artificially replaced half of the arboreal nests to terrestrial environments and recorded temperature in and outside of the experimental terrestrial nest and original arboreal nests. We also examined egg survival and hatching rate for all the nests. 4. The results indicated superior heat insulation in terrestrial nests, with warmer temperatures inside than outside the nests, especially at night, which led to a high egg survival rate. Therefore, terrestrial ovipositing should be valid under cold weather conditions. This may be related to the evolutionary history of oviposition site plasticity of this genus, which originally had an arboreal oviposition trait but evolved into terrestrial site use owing to global cooling. 5. Our novel insights into the evolution and adaptivity of foam nesting and oviposition site use in Z. arboreus make a significant contribution to animal ecology.

The increasing spread of marine non-indigenous species (NIS) due to the growth in global shipping traffic is causing widespread concern for the ecological and economic impacts of marine bioinvasions. Risk management authorities need tools to identify pathways and source regions of priority concern in order to better target efforts for preventing NIS introduction. The probability of a successful NIS introduction is affected by the probability that a marine species entrained in a transport vector will survive the voyage between origin and destination locations, and establish an independently reproducing population at the destination. Three important risk factors are voyage duration, range of environmental conditions encountered during transit, and environmental similarity between origin and destination. In this study, we aimed for a globally comprehensive approach of assembling quantifications of source-destination risk factors from every potential origin to every potential destination. To derive estimates of voyage-related marine biosecurity risk, we used computer-simulated vessel paths between pairs of ecoprovinces in the Marine Ecoregions Of the World biogeographic classification system. We used the physical length of each path to calculate voyage duration risk, and the cross-latitudinal extent of the path to calculate voyage path risk. Environmental similarity risk was based on comparing annual average sea surface temperature and salinity within each ecoprovince to those of other ecoprovinces. We derived three separate sets of risk quantifications, one each for voyage duration, voyage path, and environmental similarity. Our quantifications can be applied to studies that require source-destination risk estimates. They can be used separately or combined, depending on the importance of the types of source-destination risks that might be relevant to particular scientific or risk management questions or applications.

Aim Identification of taxonomically cryptic species is essential for the effective conservation of biodiversity. Freshwater-limited organisms tend to be genetically isolated by drainage boundaries, and thus may be expected to show substantial cryptic phylogenetic and taxonomic diversity. By comparison, populations of diadromous taxa, that migrate between freshwater and marine environments, are expected to show less genetic differentiation. Here we test for cryptic diversity in Australasian populations (both diadromous and non-diadromous) of two widespread Southern Hemisphere fish species. Location Throughout both their Australian ranges (including Lord Howe Island) and localities in New Zealand (including the Subantarctic Islands and Chatham Island). Taxon Galaxias brevipinnis and Galaxias maculatus. Methods mtDNA and nuclear markers were used to assess the presence of cryptic species and to determine if differences in species ecology could influence the degree of cryptic diversity. Results Both mtDNA and nuclear markers reveal putative cryptic species within these taxa. The substantial diversity detected within G. brevipinnis may be explained by its strong climbing ability which allows it to form isolated inland populations. In island populations, G. brevipinnis similarly show deeper genetic divergence than those of G. maculatus, which may be explained by the greater abundance of G. maculatus larvae in the sea allowing more ongoing dispersal. Main conclusions Our study highlights that even widespread, ‘high-dispersal’ species can harbour substantial cryptic diversity and therefore warrant increased taxonomic and conservation attention.

Urbanization processes are taking place at a very high rate, especially in Africa, these. At the same time, a number of small mammal species, be they native of invasive, take advantage of these human-induced habitat modifications. They represent commensal communities of organisms that cause a number of inconveniences to humans, including as potential reservoirs of zoonotic diseases. We studied via live trapping and habitat characterization such commensal small mammal communities in small villages to large cities of Senegal, to try understand how the species share this particular space. Seven major species were recorded, with exotic invasive house mice (Mus musculus) and black rats (Rattus rattus) dominating in numbers. The shrew Crocidura olivieri appeared as the main and more widespread native species, while native rodent species (Mastomys natalensis, M. erythroleucus, Arvicanthis niloticus and Praomys daltoni) were less abundant and/or more localized. Habitat preferences, compared between species in terms of room types and characteristics, showed differences between house mice, black rats and M. natalensis especially. Niche (habitat component) breadth and overlap were measured. Among invasive species, the house mouse showed a larger niche breadth than the black rat, and overall, all species displayed high overlap values. Co-occurrence patterns were studied at the locality and local scales. The latter show cases of aggregation (between the black rat and native species, for instance) and of segregation (as between the house mouse and the black rat in Tambacounda, or between the black rat and M. natalensis in Kédougou). While updating information on commensal small mammal distribution in Senegal, a country submitted to a dynamic process of invasion by the black rat and the house mouse, we bring original information on how species occupy and share the commensal space, and make predictions on the evolution of these communities in a period of ever-accelerating global changes.

Poyang Lake is an essential natural wetland in the Yangtze River basin and plays a vital role in maintaining the ecosystem function and ecological security in the middle and lower reaches of the Yangtze River. However, the relative importance and spatial heterogeneity of the impacts of human activities and land use changes on ecological security needs to be further explored. Here, we analyzed the habitat quality level around Poyang Lake in 2022 and explored the factors of habitat quality change from a geographical perspective. The land use structure changes around the Poyang Lake basin from 2000 to 2022 were quantitatively analyzed, and then the relative importance and spatial heterogeneity of each factor on ecological security changes were investigated using geographic probes. The results show that (1) The worst quality habitat (0–0.1) consists mainly of construction land (1624.9 km2) with an area of 1634.64 km2; (2) Construction land continues to increase with the most significant change, and the dynamic land use attitude is 0.47. Grassland and mudflats have the greatest decrease. The increase in cultivated land in different periods is mainly due to the shift of water surface and forest land; (3) Wetland land use change drivers are more influenced by the interaction of socioeconomic factors. The explanatory degrees of the interaction between population density and total year-end population and population density and administrative area are greater than 0.84. The data are greater than the explanatory degrees of every single factor, indicating that the land use change is mainly coupled with population density, total year-end population, and administrative area. These results reveal that human activities influence the degradation of wetlands around the Poyang Lake area. This study has significant reference value for coordinating human–land relationships in Poyang Lake, optimizing land management policy, and improving the sustainable development of cities

With global climates changing rapidly, animals must adapt to new environmental conditions with altered weather and phenology. Key to adapting to these new conditions is adjusting the timing of reproduction to maximize fitness. Using a long-term dataset on a wild population of yellow-bellied marmots (Marmota flaviventer) at the Rocky Mountain Biological Laboratory (RMBL), we investigated how the timing of reproduction changed with changing spring conditions over the past 50 years. Marmots are hibernators with a four-month active season. It is thus crucial to reproduce early enough in the season to have time to prepare for hibernation, but not too early so as snow cover prevents access to food. Importantly, climate change in this area has increased spring temperatures by 5 oC and decreased spring snowpack by 50 cm over the past 50 years. We evaluated how female marmots adjust the timing of their reproduction in response to the changing conditions and estimated the importance of both genetic variance and plasticity in the variation in this timing. We showed that, within a year, the timing of reproduction is not as tightly linked to the date a female emerges from hibernation as previously thought. We reported a positive effect of spring snowpack but not of spring temperature on the timing of reproduction. We found inter-individual variation in the timing of reproduction, including low heritability, but not in its response to changing spring conditions. There was directional selection for earlier pup emergence date since it increased the number and proportion of pups surviving their first winter. Taken together, the timing of marmot reproduction might evolve via natural selection, however, plastic changes will also be extremely important as long as plasticity is not limited. Further, future studies on the marmots should not operate under the assumption that females reproduce immediately following their emergence.

The subgenus Aschizomys belongs to the genus Alticola (Central Asian mountain vole) and consists of two species: Alticola macrotis and Alticola lemminus. Phylogenetic relationships within the subgenus Aschizomys remain obscure due to limited sampling, an insufficient number of molecular markers used in phylogenetic studies, and paraphyly observed on mitochondrial trees. In this work, to infer reliable phylogenetic relationships and evaluate putative scenarios of ancient hybridization within the subgenus, we applied double-digest restriction site–associated DNA paired-end (quaddRAD) sequencing to 20 DNA samples (20 individuals), including five species of the genus Alticola, and dated the divergence of cytochrome b (cytb) lineages within Aschizomys using a “second calibration” approach. We showed monophyly of the two species on the basis of thousands of nuclear loci and demonstrated traces of introgression also in the nuclear genome. Observed paraphyly in cytb could be explained by an introgression event rather than incomplete lineage sorting. This explanation was confirmed by an analysis of the cytb divergence time. Overall, our results support the hypothesis of extensive migration of the Aschizomys species during the Late Pleistocene, with this migration leading to population divergence and introgression. We expect our article to become a starting point for a series of rigorous studies on the population history of the genus Alticola as a whole.

Early life adversity predicts shorter adult lifespan in several animal taxa. Yet, work on long-lived primate populations suggests the evolution of mechanisms that contribute to resiliency and long lives despite early life insults. Here, we tested associations between individual and cumulative early life adversity and lifespan on rhesus macaques at the Cayo Santiago Biological Field Station using 50 years of demographic data. We performed sex-specific survival analyses at different life stages to contrast short-term effects of adversity (i.e., infant survival) with long-term effects (i.e., adult survival). Rhesus macaques exposed to adversity at birth suffered a significant increase in mortality risk during infancy with both individual and cumulative adversities having the highest impact among affected females. However, when considering adult lifespan, affected males showed higher vulnerability to both individual and cumulative adversities early in life. Our study shows profound immediate effects of insults at birth on female infant cohorts and suggests that affected female adults are more robust (i.e., viability selection). In contrast, adult males who experienced harsh conditions early in life showed an increased mortality risk at older ages as expected from hypotheses of long-term effects of individual, as well as cumulative, adversity early in life. Our study reveals that mortality risk during infancy is mainly driven by the type of adversity, rather than their accumulation at birth. However, cumulative adversity seems to play a major role in adult survival. Our analysis suggests sex-specific selection pressures on life histories and highlights the need for studies addressing the effects of early life adversity across multiple life stages. This information is critical for planning life stage-specific strategies of conservation interventions.

Animal dietary choices help understand a species’ feeding niche and are particularly relevant in conservation management. In this study, we aimed to gather knowledge on food niche and the foraging ecology of the Grizzled Giant Squirrel (Ratufa macroura) in Chinnar Wildlife Sanctuary, Southern Western Ghats, Kerala, India. Specifically, the objectives were to identify food composition, the seasonal variation in food choice and feeding technique. Through focal animal sampling, the Grizzled Giant Squirrel in Chinnar Wildlife Sanctuary was found to feed on 30 plant species belonging to 18 families. The most utilized plant family was Fabaceae, with eight species, followed by Moraceae (four species) and Anacardiaceae (two species). The feeding species included 22 trees, four climbers, one liana, one paraphyte, one shrub and one succulent species. The maximum duration of feeding was observed on Bauhinia racemosa (19.79%), followed by Tamarindus indica (14.08%) and Nothopegia beddomei (9.89%). The squirrel’s choice of diet was primarily affected by the availability of food tree species and food items rather than the season and non-tree species also have been reported from the diet of Grizzled Giant Squirrel. Even though the Grizzled Giant Squirrel shows plasticity in the food niche, the availability of mature trees and plants appears important for its conservation in the fragmented riparian forest in the Western Ghats, southern India.

1. The fixation index, FIS has been a staple measure to detect selection or departures from random mating in populations. However, current Next Generation Sequencing (NGS) cannot easily estimate Fis, in multi-locus gene families, which contain multiple loci having similar or identical arrays of variant sequences of ≥1 kilobase, which differ at multiple positions. In these families, high-quality short-read NGS data typically identify variants, but not the genomic location, which is required to calculate Fis (based on locus-specific observed and expected heterozygosity). Thus, to assess assortative mating, or selection on heterozygotes, from NGS of multi-locus gene families, we need a method that does not require knowledge of which variants are allelic at which locus in the genome. 2. We developed such a method. Like Fis, our novel measure, 1His, is based on the principle that positive assortative mating, or selection against heterozygotes, reduces within-individual variability relative to the population. 3. We demonstrate high accuracy of 1His on a wide-range of simulated scenarios, and two datasets from natural populations of penguins and dolphins. 4. 1His is important because multi-locus gene families are often involved in assortative mating, or selection on heterozygotes. 1His is particularly useful for multi-locus gene families such as toll-like receptors, the major-histocompatibility-complex in animals, homeobox genes in fungi and self-incompatibility genes in plants.