Dung beetle serve as valuable indicators for studying environmental changes and as model systems for exploring ecosystem functionality. By analyzing the diversity and composition of gut microbiota in Catharsius molossus under starvation and refeeding conditions, this study investigates the effects of dietary states on the gut microbiota of these insects. Artificial rearing methods, along with 16S rRNA high-throughput sequencing and bioinformatics, were used to analyze Catharsius molossus gut microbiota under varying dietary conditions. The results indicate that at the phylum and genus levels, the gut microbiota of Catharsius molossus under refeeding conditions is more diverse than that under starvation conditions, with seven phyla and twenty-two genera showing significant differences (P < 0.05). In terms of functional prediction, the predicted functional genes of the gut microbiota were annotated to the KEGG database, revealing significant differences in thirty-two metabolic pathways at the third level (P < 0.05). Furthermore, it provides functional prediction information related to specific microbial taxa. Additionally, Dysgonomonas is speculated to participate in nitrogen fixation, and the gut microbiota of Catharsius molossus may potentially serve as a source of antimicrobial agents like anshanmycin. These findings provide novel insights into Coleoptera ecosystem microbial interactions and offer theoretical support for future applications.
Adaptive radiation as a result of ecological opportunity can have profound effects on the evolutionary outcome of species. On coral reefs, parrotfishes have been considered as one of the most dramatic examples of adaptive radiation unique in their extreme dietary specialisation. Using abrasion-resistant biomineralized teeth, parrotfishes are able to mechanically extract protein-rich micro-photoautotrophs growing in and amongst reef carbonate material. This unique ability to exploit a previously untapped trophic resource is thought to have led to the early diversification of the parrotfishes. In order to better understand the key evolutionary innovations leading to the success of these dietary specialists, we sequenced and analysed the genome of the spotted parrotfish (Cetoscarus ocellatus). Our findings reveal significant expansion, selection, and duplication within several gene families responsible for detoxification, including the cytochrome p450 gene family and non-cyp450 carboxylesterases. We find preliminary evidence that the structural mechanism responsible for the extreme hardness and biomineralization of parrotfish teeth may be a result of poly-glutamine expansion in the enamel protein ameloblastin. We also detect expansion and selection for several genes related to pigmentation and sequential hermaphroditism. Together, these results highlight a potentially complex interplay of adaptive radiation and sexual selection operating on coral reef ecosystems.
We present the first videos depicting the consumption of bats by rusty-spotted genets (Genetta maculata) inside a cave in the Republic of Congo. Following the implementation of a camera-trap monitoring protocol of interactions between cave bats and wildlife, we identified important genet activity in one of the caves in our study. Between 2022 and 2023, we recorded four events of bat or rodent consumption (including two with certainty on bats), one hunting attempt on bats and three feeding behaviors on insects. We detail the various behaviors and discuss the potential implications of genets consuming bats, rodents and insects, and in particular scavenging on dead bats. Finally, we address the potential implications of zoonotic pathogen transmission from bats to humans via genets through the bushmeat trade.
Despite belonging to the most abundant and widespread genus of freshwater fishes in the region, the carp gudgeons of eastern Australia (genus Hypseleotris) have proved taxonomically and ecologically problematic to science since the 19th century. Several molecular studies and a recent taxonomic revision have now shed light on the complex biology and evolutionary history that underlies this group. These studies have demonstrated that carp gudgeons include a sexual/unisexual complex (five sexual species plus an assortment of hemiclonal lineages), many members of which also co-occur with an independent sexual relative, the western carp gudgeon (H. klunzingeri). Here we fill yet another knowledge gap for this important group by presenting a detailed molecular phylogeographic assessment of the western carp gudgeon across its entire and extensive geographic range. We use a suite of nuclear genetic markers (SNPs and allozymes) plus a matrilineal genealogy (cytb) to demonstrate that H. klunzingeri s.l. also displays considerable taxonomic and phylogeographic complexity. All molecular datasets concur in recognizing the presence of multiple candidate species, two instances of historic between-species admixture, and the existence of a natural hybrid zone between two of the three candidate species found in the Murray Darling Basin. We also discuss the major phylogeographic patterns evident within each taxon. Together these analyses provide a robust molecular, taxonomic, and distributional framework to underpin future morphological and ecological investigations on this prominent member of regional freshwater ecosystems in eastern Australia.
1: Passive Acoustic Monitoring (PAM) revolutionises ecological research, utilizing sounds for species-specific inferences. However, PAM generates large volumes of data, posing challenges in annotation, classification, and review complexity, necessitating efficient data management strategies. 2: Given this particular need, this research aimed to improve the performance of a pattern-matching algorithm for detecting signals of interest in two nocturnal bird species. The study pursued two main objectives: first, to evaluate various similarity scores and determine the optimum one through a sensitivity-specificity analysis. Second, we investigate potential relationships between species-specific spectral features, such as high, low, and peak frequencies, and the algorithm’s performance by reviewing and comparing their dispersion with a Levene test. 3: The outcomes demonstrated a generally favorable algorithm performance, achieving up to 80% sensitivity and specificity. This underscores its effectiveness in identifying target signals. Our investigation indicated that factors like individuality, which could be reflect on the spectral features, could potentially impact the algorithm’s efficacy. 4: ARBIMON provides transformative collaborative solutions in the field of bioacoustics. However, additional research is imperative to fully grasp the performance and potential applications of such tools. This exploration extends beyond ARBIMON to encompass the burgeoning technologies within the discipline.
During ontogeny, the increase in body size forces species to make trade-offs between their food requirements, the conditions necessary for growth and reproduction as well as the avoidance of predators. Ontogenetic changes are leading species to seek out habitats and food resources that meet their needs. These aspects are interesting to study in the case of deep pelagic fishes, as a significant part of the community migrates vertically at night to feed in the productive surface layer, while other species remain at depth. To this end, ontogenetic changes in nocturnal habitat (vertical use of the water column) and in the type of food resources (based on stable isotopes of nitrogen) were investigated in 12 species of deep pelagic fish from the Bay of Biscay in the Northeast Atlantic. Our results revealed the existence of major differences in the ontogenetic strategies employed by deep pelagic fishes. Some species showed ontogenetic changes in both vertical habitat use and food resources (e.g. Lampanyctus crocodilus and Melanostigma atlanticum). In contrast, other species showed no ontogenetic change (e.g. Searsia koefoedi and Notoscopelus kroyeri). Some species only changed food resources (e.g. Myctophum punctatum, Arctozenus risso, and Serrivomer beanii), while others seemed to be influenced more by depth than by trophic features (e.g. Xenodermichthys copei and Argyropelecus olfersii). These results suggest that to meet their increasing energy requirements during ontogeny, some species have adopted a strategy of shifting their food resources (larger prey or prey with a higher trophic level), while others seemed to maintain their food resources but are most likely increasing the quantity of prey ingested. In addition, some species opted for a habitat change to greater depths at adult age to limit the energy expenditure associated with migration, while others continued to feed at the surface at night.
Most parasite species infect multiple host species, and reciprocally, most hosts are infected by multiple parasites. This leads to complex webs of interactions that influence disease within the community, making it challenging to understand and predict disease spread within the community and epidemics. Here, we used network approaches to analyze a multi-year time series dataset that includes eight zooplankton host species (in the Daphnia and Ceriodaphnia genera) and seven microparasite species to examine patterns of cross-species transmission. These analyses suggest that parasite species varied in their ability to infect multiple host species and in which host species they most commonly infected. Three parasites (the bacteria Pasteuria ramosa and Spirobacillus cienkowskii and the oomycete Blastulidium paedophthorum) showed signatures of relatively high cross species transmission, while the others seemed more restricted. Even for the three common multihost parasites, our approach also revealed differences in patterns of potential cross species transmission. For P. ramosa, two host species, Daphnia dentifera and D. retrocurva, seem particularly likely to transmit across species; in contrast, for S. cienkowskii, no host species stands out as particularly important for cross species transmission. Additionally, these patterns matched those describing epidemic size, suggesting that infected host density may drive cross-species transmission. These results are based on observations of patterns of infection in natural communities, and therefore we cannot draw definitive conclusions about interspecific transmission in lakes. However, some of the patterns are supported by additional lines of evidence, and others point to interesting avenues for future research. Together, these findings provide additional evidence that network approaches can provide valuable insights into patterns of transmission in complex multihost-multiparasite communities in nature.
In root-nodule symbioses (RNS) between nitrogen (N) fixing bacteria and plants, bacterial symbionts cycle between nodule-inhabiting and soil-inhabiting niches that exert differential selection pressures on bacterial traits. Little is known about how the resulting evolutionary tension between host plants and symbiotic bacteria structures naturally occurring bacterial assemblages in soils. We used DNA cloning to examine soil-dwelling assemblages of the actinorhizal symbiont Frankia in sites with long-term stable assemblages in Alnus incana ssp. tenuifolia nodules. We compared: 1) phylogenetic diversity of Frankia in soil vs. nodules, 2) change in Frankia assemblages in soil vs. nodules in response to environmental variation: both across succession, and in response to long-term fertilization with N and phosphorus, and 3) soil assemblages in the presence and absence of host plants. Phylogenetic diversity was much greater in soil-dwelling than nodule-dwelling assemblages, and fell into two large clades not previously observed. Presence of host plants was associated with enhanced representation of genotypes specific to A. tenuifolia, and decreased representation of genotypes specific to a second Alnus species. The relative proportion of symbiotic sequence groups across a primary chronosequence was similar in both soil and nodule assemblages. Contrary to expectations, both N and P enhanced symbiotic genotypes relative to non-symbiotic ones. Our results provide a rare set of field observations against which predictions from theoretical and experimental work in the evolutionary ecology of RNS can be compared.
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.
Livebearing fishes are a standard model for studying the effect of predation on prey biology. Numerous studies have found differences in life history, sexual selection, behavior, and morphology between populations of the same species that co-occur with predators and those that do not. Alfaro cultratus is a livebearing fish with populations in different predation environments, but unlike other livebearers, this species also has an extreme body shape that is laterally compressed. Given this unusual morphology, we asked if predation environment would still predict overall body shape, as has been documented in other species. We collected specimens from both predator and no-predator sites in Costa Rica. We used a geometric morphometrics analysis to determine if body shape is affected by the predation environment while controlling for size and river gradient. Body shape does indeed differ between predation environments; however, the observed differences contrast with the patterns found in other livebearer systems. Alfaro cultratus in predation environments had deeper and shorter bodies and deeper caudal peduncles than those found in environments without dominant fish predators.
Tridacna maxima (T. maxima) are widely distributed in shallow areas near coral reefs and hold significant commercial value as a food source and for marine tourism. However, it has been extensively harvested and depleted in many regions, leading to it being listed as endangered species by the International Union for Conservation of Nature (IUCN). While marine protected areas (MPAs) are considered effective conservation tools, it remains uncertain whether existing MPAs adequately protect these vulnerable giant clams. Here, we employed a Species Distribution Models (SDMs) approach, combining occurrence records of T. maxima with environmental variables, to predict their distribution and capture spatiotemporal changes. The findings revealed the importance of land distance and light at bottom in determining the distribution of T. maxima, with suitable habitats predominantly found in shallow coastal waters rather than deep sea areas. Furthermore, we modeled potential distribution areas for T. maxima in 2050 and 2100 under different climate change scenarios, highlighting varying impacts on suitable habitats across different model predictions. To evaluate current conservation gaps, we conducted an analysis by overlaying suitable areas with existing protected areas. The results showed that the potential distribution area of T. maxima is 1,519,764.73 km2, accounting for only 16.10% of the total protected areas. It became evident that the existing protected areas are insufficiently large or well-connected, suggesting their ineffectiveness in safeguarding giant clams. Therefore, management efforts should focus on establishing a network of MPAs along the coastlines of West Pacific-Indonesia, matching the dispersal capability of giant clams. These findings provide valuable insights for the conservation of endangered giant clams, offering a scientific foundation for designing MPA networks in the Indo-Pacific region.
Wildlife monitoring is a crucial component of conservation management, with reliable field surveys being important for trend analysis and population viability modelling. Unoccupied aircraft systems (UAS), also known as drones, are rapidly supplanting manned aircraft for aerial wildlife counts. Here we investigated and compared the impacts of drone presence on two large terrestrial mammals from Tasmania, Australia—Bennett’s wallaby (Notamacropus rufogriseus), and Forester kangaroo (Macropus giganteus tasmaniensis) —using a commercial quadcopter model: DJI Phantom 4 Pro. Further, a ground bird, the domestic chicken (Gallus gallus domesticus), was used as a model organism to further investigate behavioural responses of ‘aerial aware’ species to drones. We found that M. giganteus tasmaniensis and N. rufogriseus started to exhibit noticeable changes in behaviour, including evasion, when the drone motor sound exceeded ~50 decibels (dB) as heard from the ground (at flight altitudes of 30 – 50 m). At lower sound levels (48 dB and below, above 50 m), the animal’s response was minimal. The response of G. gallus domesticus to the drone was remarkably similar to that of the Macropus species, despite the species generally being more susceptible to, and instinctively vigilant against drone-sized aerial predators such as raptors. This study has established the baseline information required to understand the limits of drone operations, in terms of target disturbance, for macropod surveys.
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.
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.
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.
Parentage analyses via molecular markers have revealed multiple paternity within the broods of polytocous species, reshaping our understanding of animal behavior, ecology, and evolution. In a meta-analysis of multiple paternity in bird and mammal species, we conducted a literature search and found 138 bird and 64 mammal populations with microsatellite DNA paternity results. Bird populations averaged 19.5% multiple paternity and mammals more than twice that level (46.1%). We used a Bayesian approach to construct a null model for how multiple paternity should behave at random among species, under the assumption that all mated males have equal likelihood of siring success, given mean brood size and mean number of sires. We compared the differences between the null model and actual probabilities of multiple paternity. While a few bird populations fell close to the null model, most did not, averaging 34.0-percentage points below null model predictions; mammals had an average probability of multiple paternity 13.6-percentage points below the null model. Differences between bird and mammal species were also subjected to comparative phylogenetic analyses that generally confirmed our analyses that did not adjust for estimated historical relationships. Birds exhibited extremely low probabilities of multiple paternity, not only compared to mammals, but relative to other major animal taxa. The generally low probability of multiple paternity in birds might be produced by a variety of factors, including behaviors that reflect sexual selection (extreme mate guarding or unifocal female choice) and sperm competition (e.g., precedence effects favoring fertilization by early or late matings).
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.