Colour polymorphism can be maintained by colour morph-specific benefits across environmental conditions. Currently, the amount and duration of snow cover during winter decreases especially in northern latitudes, which can alter the potential for camouflage of animals with light and dark morphs. Tawny owls, Strix aluco, are colour polymorphic avian predators with dark (brown) and light (grey) colour morphs, where the grey morph is presumed to enjoy camouflage benefits under snowy conditions. We studied the two tawny owls’ morphs’ camouflage potential using passerines’ probability to detect and mob in the wild during spring, autumn, and winter with and without snow. We find that grey tawny owls are both less likely to be detected and have a lower probability of being mobbed compared to brown tawny owls only during snowy winters. The two colour morphs therefore experience differential benefits across snow conditions, which may help to maintain colour morphs in the population, although further warming of winter climate will reduce the potential for camouflage for grey tawny owls in northern latitudes.

Fallback foods (FBF), classified into staple and filler types, are low-quality food resources chosen by animals due to a shortage of preferred food during a specific period. The selection of lichens as FBF for Yunnan snub-nosed monkeys (Rhinopithecus bieti) represents a unique ecological adaptation and evolutionary development in the animal kingdom. This study investigates the yearly dietary selection of five R. bieti groups to address the issues and elucidate the nutritional value and ecological selection of lichens for this monkey species, which resides at the highest altitude among nonhuman primates. The results indicate that the consumed lichens serve as the staple FBF. Two main lichen species taken by the monkeys are Bryoria spp. and Usnea longissimi, with Bryoria spp. being the primary choice (67.25 ± 12.20% compared to 15.79 ± 11.66% from U. longissimi). Bryoria spp. provides a higher level of digestible fiber (NDF) and a lower level of tannin, fat, ADF, and energy compared to U. longissimi, which offers higher availability. Lichens are the dominant food and nutritional resource for the monkey species during the dry season, while they serve as a primary food source rather than a nutritional resource during the wet season. Therefore, they compensate for nutrients from other food types, such as fruits, seeds, and leaves. Compared to other Asian colobine counterparts, this species consumes the highest amount of lichens but the lowest proportions of leaves, flowers, and seeds. This dietary pattern demonstrates a specific type of ecological selection and evolutionary development during the Quaternary. The biomass of lichens in the monkeys’ habitat has significantly decreased due to environmental degradation. This study also provides evidence and information to develop or amend conservation strategies and guidelines for the dietary management of captive Yunnan snub-nosed monkeys.

Maternal provisioning and the developmental environment are fundamental determinants of offspring traits, particularly in oviparous species. However, the extent to which embryonic responses to these factors differ across populations to drive phenotypic variation is not well understood. Here, we examine the contributions of maternal provisioning and incubation temperature to variation in hatchling morphological and metabolic traits across four populations of the American alligator (Alligator mississippiensis), encompassing a large portion of the species’ latitudinal range. Our results show that whereas the influence of egg mass is generally consistent across populations, responses to incubation temperature show extensive population-level variation in several fitness-related traits, including mass, head length, head width and residual yolk mass. Additionally, the influence of incubation temperature on developmental rate is greater at northern populations, while the allocation of maternal resources towards fat body mass is greater at southern populations. Overall, our results suggest that responses to incubation temperature, relative to maternal provisioning, are a larger source of interpopulation phenotypic variation and may contribute to the local adaptation of populations.

Winter, the most challenging season for animals, is usually accompanied by extremely cold temperatures and limited food resources. Harsh winter conditions force birds to develop behavioral and physiological adaptations to reduce mortality. Birds might select for sexual segregation to reduce conflict between different social hierarchies at the population level. They can also adjust their body conditioning via fat reserve to balance the trade-off between starvation and predation at the individual level. Using mist-netting surveys and bird banding, we traced 61 orange-flanked bush-robin (Tarsiger cyanurus), an abundant and easily-observed long-distance migratory bird exhibiting delayed plumage maturation, to better understand the winter adaptation of these songbirds. We found that the number of 2yr+ adult males with bright-blue plumage was significantly lower than the number of males with olive-brown plumage. However, the sex-ratio was only slightly skewed to males with olive-brown plumage, suggesting that habitat-type influences sexual segregation. This robin tends to become heavier and store more fat over the course of winter, as they can fine-tune their fat reserve in response to changes in weather (including temperature, humidity, and snowfall) and food abundance. Interestingly, capturing the birds may also have a significant positive effect on their fat reserve. Overall, these results improved our understanding of the flexibility in adaptation of small passerine birds wintering in a subtropical forest and provided vision for considering the inevitable influence by ornithology field methods.

All animals and plants respond to changes in the environment during their life cycle. This flexibility is known as phenotypic plasticity and allows organisms to cope with variable environments. A common source of environmental variation is predation risk, which describes the likelihood of being attacked and killed by a predator. Some species can respond to the level of predation risk by producing morphological defences against predation. A classic example is the production of pedestals and head spikes in the water flea, Daphnia pulex, which defend against predation from Chaoborus midge larvae. Previous studies of these defences have focussed on changes in pedestal size and the number of spikes along a gradient of predation risk. Although these studies have provided a model for continuous plasticity, they do not capture the whole-organism shape response to predation risk. In contrast, studies in fish and amphibians focus on shape as a complex, multi-faceted trait made up of different variables. In this study, we analyse how multiple aspects of shape change in D. pulex along a gradient of predation risk from C. flavicans. These changes are dominated by the inducible morphological defence, but there are also changes in the size and shape of the head and the body. We detected change in specific modules of the body plan and a level of integration among modules. These results are indicative of a complex, multi-faceted response to predation and provide insight into how predation risk drives variation in shape and size at the level of the whole organism.

Species richness has been shown to decrease, and elevational range increase (the Rapoport effect), with elevation as a consequence of biotic and abiotic factors, but patterns are inconsistent across taxonomic groups. Despite being an important indicator taxon and component of local communities, Orthoptera distributions at higher elevations in Europe remain unclear. We investigated the relationship of Orthoptera species richness and elevational range with elevation by conducting field studies at 28 sites across three study areas in the Pyrenees mountains, Europe. We found that species richness declined with elevation. Study area and the site-specific factors of sampling effort, topography (slope) and vegetation structure (density and cover) were also important predictors of species richness. We did not observe a Rapoport effect, with elevational range peaking at mid-elevation instead. Smaller elevational ranges found at high elevations may be due to a combination of sampling over a restricted elevational range and the presence of specialist high-elevation species. We also explored the composition of Orthoptera assemblages using multivariate methods, finding no clear effect of elevation, slope or vegetation structure on these communities, although study area somewhat influenced assemblages. To our knowledge, this is the first study of the Rapoport effect along an elevational gradient using insects as a study system in Europe. We argue that our findings are useful for understanding species distributions with elevation at the interface between local and regional scales. Clarifying the biotic and abiotic predictors of species distribution is important for informing conservation efforts and predicting consequences of climate change.

Fish play vital roles in river ecosystems; however, traditional investigations of fish usually cause certain ecological damage. Extracting DNA from aquatic environments and identifying DNA sequences offers an alternative, non-invasive approach for detecting fish species. In this study, environmental DNA (eDNA), coupled with PCR and next-generation sequencing, and electrofishing were used to compare their effects in identifying fish community characteristics. In three subtropical rivers of southern China, fish specimens and eDNA in water were collected from headwaters to estuaries. Both eDNA OTU richness and individual abundance (including number and biomass) could group 38 sampling sites into eight spatial zones with significant differences in local fish community composition. Compared with the order-/family-level grouping, the genus-/species-level grouping could more accurately recognize the differences between upstream zones I − III, midstream zones IV − V, and downstream zones VI – VIII. From headwaters to estuary, two environmental gradients significantly influenced the longitudinal distribution of fish species, including the first gradient composed of habitat and physical water parameters and the second gradient composed of chemical water parameters. The high regression coefficient of alpha diversity between eDNA and electrofishing methods as well as the accurate recognition of dominant, alien, and biomarker species at each spatial zone indicated that eDNA could characterize fish community attributes at a similar level of traditional approach. Generally, our results demonstrated that eDNA metabarcoding can be used as an effective tool in revealing fish composition and diversity, which is important for using the eDNA technique in aquatic field monitoring.

Root system architecture is limited by phylogenetic relationships and ultimately affect the biomass allocation of resource acquisition organs. However, many studies have only focused on the impact of environmental driven trait variation and biomass allocation on root system architecture, neglecting the impact of phylogenetic relationships. Therefore, biomass allocation and phylogenetic relationship affect the root system architecture and its variation patterns were investigated in annual ephemerals. We found that the interspecific variation of root tissue density (RTD) was the highest (51.63%), and the topological index (TI) was the lowest (5.92%). Moreover, the range of intraspecific variation for specific root length (SRL) and specific surface area (SRA) is high, and the TI is low. This convergence and divergence of root traits reflect the Phenotypic plasticity of roots and their adaptation to environmental filtering and interspecific competition. Maximum root depth (MRD) was detected significantly and weakly phylogenetic signal (0

Climate change is likely to drive widespread species range shifts and extirpations, mostly on the warm distribution edges, where habitat tends to be fragmented, of lower quality, support lower population density, and at greater risk from extreme weather events. In the Intermountain West, future climate will likely be warmer and drier, driving a reduction in sagebrush (Artemesia sp.) and other shrubland cover. Among the species threatened by more xeric climate is the Greater sage-grouse (Centrocercus urophasianus), which depends on sagebrush for forage and shelter, though their response to temperature is not well studied. We deployed 75 data loggers across two valleys in southern Utah and Nevada, near the southern edge of sage-grouse distribution, and collected temperature data for 27 months. We used random forest models to test the impacts of temperature, land cover, and topography on sage-grouse habitat selection and found that temperature influenced selection in all seasons and both sites. In Utah, the warmer site, sage-grouse selected areas near trees during the extremes of both winter and summer. In autumn and spring those extremes were rarer and sage-grouse avoided habitat near trees. Conversely, sage-grouse in the cooler Nevada site selected contiguous patches of sagebrush in extremes periods but only selected habitat near trees during winter cold, avoiding trees during summer. Our findings show that extreme temperatures drive sage-grouse to select habitat near trees despite the risk likely posed by avian predators. The difference between the Utah and Nevada sites suggests that sage-grouse prefer sagebrush as thermal shelter but that it may be inadequate during the hottest times, forcing riskier selection. These models point toward a more mechanistic understanding of how sage-grouse distribution may retract at its warm edges. This will refine our understanding of seasonal habitat requirements and inform management decisions to prioritize thermal refugia for an imperiled species.

Although natural flooding plays a crucial role in shaping the composition of aquatic communities, most rivers around the world have been regulated or dammed for anthropogenic purposes. This affects the biological and chemical composition of these ecosystems. Although studies have demonstrated the negative effects of river regulation on aquatic invertebrate communities globally, there is a scarcity of research in Africa, despite its vulnerability to anthropogenic use. This study aimed to compare aquatic invertebrate communities between the regulated Phongolo River and the unregulated Usuthu River, South Africa and to determine whether the largest lake in the region (Lake Nyamithi), which receives water from both rivers, would show a stronger resemblance to either of the two rivers. Aquatic invertebrate and water samples were collected from 2012 to 2018 over several seasons. The Usuthu River demonstrated a diverse and sensitive aquatic invertebrate community, emphasising its high conservation value. Despite maintaining relatively high aquatic invertebrate diversity, the Phongolo River demonstrated effects of anthropogenic impact, with more resilient taxa to changes in water quality and flow compared to the Usuthu River. Mismanagement and excessive water use may lead to the loss of any remaining sensitive aquatic invertebrate communities in this river. The presence of invasive molluscan species such as Physella acuta and Tarebia granifera in the Phongolo River and Lake Nyamithi also poses a threat to the aquatic invertebrate community in the system. These invasive species are currently absent from the Usuthu River although other invasive species, such as the Australian redclaw crayfish, are found in both river systems. Lake Nyamithi displayed a unique aquatic invertebrate community, distinct from both rivers and their floodplains. This study provides important baseline information on the Usuthu River’s aquatic invertebrates and emphasises the need to maintain adequate water flow in rivers and floodplains to protect biodiversity and sensitive species.

Ectotherms are expected to be particularly vulnerable to climate change driven increases in temperature. Understanding how populations adapt to novel thermal environments will be key for informing mitigation plans. We took advantage of threespine stickleback (Gasterosteus aculeatus) populations inhabiting adjacent geothermal (warm) and ambient (cold) habitats to test whether their evolutionary divergence was adaptive using field reciprocal transplant experiment. We found evidence for adaptive morphological divergence, as growth (length change) in the non-native habitat was found to relate to head, posterior and total body shape. Higher growth in fish transplanted to a non-native habitat was found to be associated with shape profiles closer to that of the native fish. The consequences of transplantation were asymmetric with cold sourced fish transplanted to the warm habitat suffering from lower survival rates and greater parasite prevalence than warm sourced fish transplanted to the cold habitat. We also found evidence for divergent shape allometries that related to growth. Our findings suggest that wild populations can adapt quickly to thermal conditions. However, immediate transitions to warmer conditions may be particularly difficult.

Geological events and historical environmental change can strongly affect the genetic structures and differentiation of fish populations. Although the central region of the Yunnan-Guizhou Plateau contains the highest concentration of rift-subsidence lakes in China, the effects of key geological events on the distributions and genetic structures of the regional fauna remain poorly understood. Fishes of the genus Sinocyclocheilus are endemic to the Yunnan-Guizhou Plateau, where they are found in karst landforms. As a result of environmental pollution and other human activities, Sinocyclocheilus populations have decreased sharply, and the genus is currently listed under Class II of the nationally protected animals classification in China. Examining the phylogeographic patterns of Sinocyclocheilus fishes can be useful for elucidating the spatio-temporal dynamics of their population size, dispersal history and extent of geographical isolation, thereby providing a theoretical basis for their protection. Here, we used Restriction Site Associated DNA Sequencing (RAD-seq) to investigate the evolution of Sinocyclocheilus fishes. Our analysis supports the endemicity of Sinocyclocheilus, and identifies the formation of Dianchi Lake and Fuxian Lake as key geological events shaping Sinocyclocheilus population structure. We estimate that the most recent common ancestor (MRCA) of Sinocyclocheilus fish occurred in the Central Yunnan Basin 3.75~3.11 Ma. It is the first time to prove that the altitude change has a great influence on the genetic variation among the populations of Sinocyclocheilus. We discuss the implications of our results for the protection and management of Sinocyclocheilus grahami and other cave fishes.

Habitat fragmentation can increase the chance of population bottlenecks and inbreeding, and may ultimately lead to reduced fitness and local extinction. Notelaea lloydii is a native olive species endemic to Australia and listed as vulnerable due to its restricted distribution. A recent molecular systematics study has revealed there might be some geographic structuring among the N. lloydii populations. Therefore, we undertook a genome wide Single Nucleotide Polymorphism (SNP) analysis to determine levels and patterns of genetic diversity, inbreeding and gene flow within and among N. lloydii populations in south-eastern Queensland (SE-QLD). Furthermore, as the reproductive phase of a plant’s life history has a profound influence on genetic diversity, life history reproductive traits were also studied. Our SNP analysis revealed low genetic diversity, inbreeding and significant genetic structuring even among proximate populations. Results of a flower and fruit bagging experiment in two consecutive seasons revealed that N. lloydii produced many flowers but only a few fruits survived to maturity. There were no differences in bagged and un-bagged flowering and fruiting rates and therefore, we conclude that the high fruit abortion rate was probably due to inbreeding depression and/or suboptimal conditions, rather than pollinator availability and insect attack. Overall, results of this study indicate that the populations of N. lloydii are small, inbred and genetically isolated and represent unique management units that require local conservation management due to ongoing threats associated with urbanisation.

Distyly, a floral dimorphism that promotes outcrossing, is controlled by a hemizygous genomic region known as the S-locus. Disruptions of genes within the S-locus are responsible for the loss of distyly and the emergence of homostyly, a floral monomorphism that favors selfing. Using whole genome resequencing data of distylous and homostylous individuals from populations of Primula vulgaris and leveraging high-quality reference genomes of Primula we tested, for the first time, predictions about the evolutionary consequences of transitions to selfing on S-locus genes. Our results confirm the presence of previously reported homostyle-specific, loss-of-function mutations in the exons of the S-locus gene CYPᵀ, while also revealing a previously undetected structural rearrangement in CYPᵀ associated with the shift to homostyly. Additionally, we discovered that the promoter region of CYPᵀ in distylous and homostylous individuals is identical, suggesting that down-regulation of CYPᵀ via mutations in its promoter region is not a cause of shift to homostyly. Furthermore, we found that hemizygosity leads to reduced genetic diversity and less efficient purifying selection in S-locus genes compared to genes outside the S-locus, and that the shift to homostyly further lowers genetic diversity, as expected for mating-system shifts. Finally, we tested, for the first time, long-standing theoretical models of changes in S-locus genotypes during early stages of the transition to homostyly, supporting the assumption that two (diploid) copies of the S-locus might reduce homostyle viability.

Honey bees play a vital role in providing essential ecosystem services and contributing to global agriculture. However, the potential effect of climate change on honey bee distribution is still not well understood. This study aims to identify the most influential bioclimatic and environmental variables, assess their impact on honey bee distribution, and predict future distribution. An ensemble modelling approach using the BIOMOD2 package in R was employed to develop three models, i.e., a climate-only model, an environment-only model, and a combined climate and environment model. The climate-only model focused on the bioclimatic factors: radiation of the wettest and driest quarters, and temperature seasonality. By utilizing bioclimatic data from 1990 to 2009, combined with observed honey bee presence and pseudo absence data, this model predicted honey bee distribution for two future time spans: 2020-2039 and 2060-2079. The climate-only model exhibited a True Skill Statistic (TSS) value of 0.85, underscoring the pivotal role of radiation and temperature seasonality in shaping honey bee distribution. The environment-only model incorporated environmental variables: proximity to regional ecosystems (floral resources), foliage projective cover, and elevation. This model demonstrated strong predictive performance, with a TSS of 0.88, emphasizing the significance of environmental variables in determining habitat suitability for honey bees. Remarkably, the combined model had a higher TSS of 0.96, indicating that the combination of climate and environmental variables enhances the model’s performance. Predictions for the 2060-2079 period revealed a concerning trend of 100% transition of highly suitable land into moderately (0.54%), marginally (17.56%) or not suitable areas (81.9%) for honey bees. These results emphasize the critical need for targeted conservation efforts and the implementation of policies aimed at safeguarding honey bees and the vital apiary industry.

Plant secondary metabolites (PSMs) are produced by plants to overcome environmental challenges, both biotic and abiotic. We were interested in characterizing how autumn seasonality in temperate and subtropical climates affects typical PSM production in comparison to herbivory. Herbivory is commonly measured from spring to summer when plants have high resource availability and are prioritizing growth and reproduction. However, autumn seasonality also challenges plants as they cope with limited resources and prepare survival for winter. This suggests a potential gap in knowledge on how autumn seasonality affects PSM production differently from herbivory. Using meta-analysis, we recorded production of 22 different PSM subgroups from 58 published papers to detect a typical response across all PSMs. We also compared production of five phenolic subgroups – hydroxybenzoic acids, flavan-3-ols, flavonols, hydrolysable tannins, and condensed tannins. We calculated effect sizes from herbivory studies (absence to presence) and temperate to subtropical seasonal studies (summer to autumn), while considering other variables (e.g., plant type, increase in time since herbivory, temperature, and precipitation). We did not detect a shared effect of herbivory or season on PSM production across all subgroups. However, we discovered herbivory having a positive effect on flavonol production and autumn seasonality having a positive effect on flavan-3-ol and condensed tannin production. We discuss how these responses might stem from three factors: 1. some PSMs are constitutively produced by plants in autumn whereas others are induced only following herbivory, 2. plants produce metabolites with higher costs only during seasons when other resources for growth and reproduction are less available, and 3. some PSM subgroups serve more than one function for plants and such functions can be season dependent. The outcome of our meta-analysis is that autumn seasonality changes PSM production differently from herbivory, and we see value in further investigating seasonality-herbivory interactions with plant chemical defense.

A document by Ellen Yasumiishi. Click on the document to view its contents.

The existence of adult sexual dimorphism is typically explained as a consequence of sexual selection, yet coevolutionary drivers of sexual dimorphism frequently remain untested. Here, I investigate the role of sexual dimorphism in host-parasite interactions of the brood parasitic diederik cuckoo, Chrysococcyx caprius. Female diederik cuckoos are more cryptic in appearance and pose a threat to the clutch, while male diederik cuckoos are conspicuous and not a direct threat. Specifically, I examine whether sexual dimorphism in diederik cuckoos provokes threat-level sensitive responses in Southern red bishop, Euplectes orix, hosts. I use experimentally simulated nest intrusions to test whether hosts have the capacity to differentially (i) detect, and/or (ii) discriminate between, male and female diederik cuckoos, relative to controls. Overall, I found no evidence that diederik cuckoos differ in detectability, since both sexes are comparable to controls in the probability and speed of host detection. Furthermore, neither male nor female hosts discriminate between sexually dimorphic diederik cuckoos when engaging in frontline nest defences. However, hosts that witnessed a male diederik cuckoo during the trial were more than twice as likely to reject odd eggs compared to those that saw a control. Moreover, hosts were more likely to reject experimental eggs when exposed to a male compared to a female diederik cuckoo: the reverse of a beneficial threat-level sensitive response. While the cryptic appearance of female diederik cuckoos does not differentially avoid detection by hosts, it does appear to provide the benefit of anonymity given the egg rejection costs of male-like appearance in the nest vicinity. These findings have implications for the evolution and maintenance of sexual dimorphism across the Cuculidae, and highlight the value of testing assumptions about the ecological drivers of sexual dimorphism.