Animals need inhibitory control to achieve goals when taking a detour, requiring self-regulation, decision-making, and spatial awareness to suppress direct approaches and find alternative routes. In amphibians, particularly salamanders, there is a considerable lack of information regarding inhibitory control. We examined this cognitive trait in two species of salamanders, Hynobius yiwuensis and Salamandrella tridactyla, across larval and post-metamorphic stages using a detour task where they had to navigate around a transparent barrier to reach food. Results indicate significant differences in detour behavior and inhibitory control across life-history stages and between species. While larvae of H. yiwuensis performed significantly better than the metamorphs in solving the task, metamorphs of S. tridactyla outperformed their larvae, with 100% of individuals successfully reaching the food. Task success, that is, reaching the food around the barrier, increased over trials, and individuals demonstrating greater persistence and lower latency were significantly more likely to succeed. Metamorphs exhibited significantly lower latency than larvae, indicating faster decision-making overall. However, this effect varied across species as H. yiwuensis metamorphs did not show reduced latency. Pecking and reverse (retreating from the barrier, reorienting, and approaching from a different direction), used as indicators of errors, decreased over successive trials, which could be interpreted as evidence of learning. Individuals of H. yiwuensis displayed significantly higher instances of committing errors compared to S. tridactyla. As individuals were lab-reared from eggs, the difference in cognitive abilities across species and developmental stages may reflect underlying genetic differences shaped by their distinct ecological adaptations and evolutionary trajectories.

Food sharing is very common in the animal kingdom. Despite extensive research, the mechanisms underlying food sharing remain debated. Moreover, the majority of studies on food sharing in non-human animals have been conducted under controlled environments. The natural behavioral characteristics and ecological factors influencing the natural selection of food sharing are still not well understood. In this study, we introduce a method to examine food-sharing behaviors in wild birds within their natural habitat. Using two types of feeders—one permitting food sharing with conspecifics and the other providing exclusive access to food—along with infrared cameras to record feeder-triggering events, we found that azure-winged magpies did not exhibit proactive food-sharing behaviors. However, they did exhibit passive food-sharing behaviors under conditions of low food availability. Consistent with the harassment-avoidance hypothesis, the birds prioritized the sharing feeders to decrease harassment from food snatching when food was limited. These findings suggest that food sharing is likely shaped into a passive behavioral pattern under limited resources conditions, which induce conflicts within social groups. This context-dependent strategy may effectively reduce harassment costs, optimize individual access to resources to maximize individual benefits, and potentially enhance the survival of other group members.

Quagga (QM) and zebra (ZM) mussels (Dreissena bugensis and Dreissena polymorpha) are invasive bivalves forming freshwater fouling communities of high economic and environmental importance in Europe and North America. They may experience immersion in soft sediments by sedimenting particles (mostly at deeper locations or areas with high hydrodynamic activity) or while attached to burrowing unionid mussels. On the other hand, mussels located near the water surface may encounter water level decreases and air exposure during droughts. We experimentally tested mussel survival and behavioral responses to immersion in sediments and water level reduction. Interspecific differences in these responses can help understand the ongoing replacement of ZM by QM in invaded communities and less common cases of their co-existence. ZM were more resistant to both stressors, surviving longer when immersed in sediments or exposed to air. Moreover, both species survived better in coarse versus fine sediments. QM re-emerged from sediments more efficiently than ZM. In turn, ZM relocated over longer downward distances facing water level reduction compared to the behavior of individuals tested at the constant water level. Thus, ZM seem better adapted to remain at their attachment sites, survive temporary adverse conditions, and cope with dangers typical for shallow nearshore areas. On the other hand, QM perform better on soft bottoms, abandoning their attachment sites to cope with immersion in sediments. These adaptations allow QM to dominate deep-water soft sediments, whereas ZM can find refuges in areas periodically exposed to air and on unionid mussels.

Noise is ubiquitous to all biological and ecological systems and is of pivotal importance to acoustically signaling species. To counter the detrimental effects of noise, animals have adopted a range of strategies. Different strategies generally help to mitigate, but rarely restore the performance to noise-free scenarios. Here, we document that the performance of Doppler shift compensation (DSC), a highly precise echolocation behavior, is immune to various types of acoustic interference at moderately high noise levels in flying Pratt's roundleaf bats (Hipposideros pratti). The DSC performance of individual bats was quantified under 10 types of bandpass-filtered noise and echolocation calls from seven bat species, apart from a silence control condition. We found that H. pratti maintained high DSC performance across all playback conditions. Surprisingly, we found evidence that H. pratti exhibited higher DSC precision in experimental conditions of narrowband noise and echolocation calls of one heterospecific bat species. The main energy of these acoustic stimuli coincided with the minimum (terminal) frequency of the frequency-modulated component of the dominant second harmonic in the echolocation calls of H. pratti. Thus, contrary to the widespread view, acoustic interference does not universally impair motor performance, and instead, some species may exhibit improved performance under certain noise conditions.

This study aimed to investigate whether the attractiveness of female dragline silk sex pheromones in the wolf spider Pardosa pseudoannulata varies with female age, and to identify the key chemical compounds responsible for male attraction. We conducted integrated behavioral, chemical, and electrophysiological analyses. Dragline silk was collected from females of three age groups (young, middle-aged, and old). Male courtship behaviors were assessed in response to silk exposure. Silk extracts were analyzed using gas chromatography coupled with electroantennographic detection and mass spectrometry. Candidate pheromone compounds were further evaluated via electroantennography and Y-tube olfactometer assays to confirm their behavioral relevance. Male spiders exhibited significantly stronger courtship responses, shorter latency, higher palpal drumming, and increased leg vibration, toward silk from young and middle-aged females compared to older females. Three compounds—oleic acid, n-heptacosane, and squalene—were consistently identified as key pheromone components across age groups. Their electrophysiological activity was concentration and solvent dependent, while behavioral attraction was confirmed under tested conditions. In behavioral assays, synthetic versions of these compounds at 0.01 µg/µL in mineral oil significantly attracted males, confirming their role as sex pheromone components. The findings demonstrate that female age significantly influences the chemical composition and attractiveness of dragline silk pheromones in P. pseudoannulata. Younger females produce more attractive pheromone blends, guiding male mate preference. The identification of oleic acid, n-heptacosane, and squalene as bioactive compounds provides new insights into spider chemical ecology and supports potential applications in eco-friendly pest management strategies.

Myrmecophagy is one of the most common types of dietary specialization among predators. It can include exploitation of ants, termites, or both. Although ants and termites share a few traits, they are distantly related and possess different defensive mechanisms. Therefore, adaptations to ants and termites should differ, especially in arthropod predators of similar body size as their prey. We investigate offensive and defensive adaptations in Zodariidae spider genus Diores, reported to feed on termites. The ancestral state reconstruction of the diet favored termitophagy for the genus, but metabarcoding analyses revealed that only one of the four studied Diores species fed exclusively on termites. The remaining three species captured both ants and termites. Interestingly, the laboratory observations of a single species, Diores poweri, revealed a similar attack-and-retreat strategy to catch both termites and ants. Three ant species and one termite were successfully captured with a similar frequency, but the capture of Hodotermes termites was more efficient. The paralysis of Hodotermes by D. poweri was approximately 20 times faster than by an ant-eating spider Zodarion nitidum, which correspond to venom composition differences between the species. The habitus of D. poweri resembles the size, shape, movement, and the coloration of its predominant prey, Camponotus maculatus ants, suggesting Batesian mimicry. However, the modeling of the visual discrimination of coloration by potential lizard and bird predators revealed that Diores might be distinguished from Camponotus. Our results suggest that Diores spiders are specialized myrmeco-termitophagous predators, possessing effective adaptations and exploiting ants for defense.

The transmission of many pathogens depends on insect vectors, and these pathogens tend to manipulate vector behaviors after acquisition to enhance their spread. However, the underlying molecular mechanisms remain largely unknown. The pinewood nematode (PWN), the causative agent of pine wilt disease, primarily relies on Monochamus alternatus beetles for dispersal in Asia. The behavior of the beetle plays a crucial role in the spread of the pinewood nematode among host pine trees. Here, we investigated the behavioral and molecular effects of PWN loading on M. alternatus. Behavioral assay demonstrated that PWN loading significantly reduced beetle locomotion, with decreases in movement distance, speed, and activity duration. Comparative transcriptomic analysis of the muscle of beetles with and without PWN highlighted the disruptions in key energy metabolism pathways and pathways related to aging responses and neurodegenerative diseases. Gene co-expression network showed ATP synthase subunit alpha (ATP1), which was notably down-regulated by PWN loading, is central in energy metabolism and the aging process. The reduced ATP production in the muscles of beetles with PWN suggested ATP1 as a candidate gene required for locomotion control. RNA interference (RNAi) targeting ATP1 led to a decline in beetle locomotion, confirming its role as a key mediator of these locomotion changes. Overall, our findings revealed that the pinewood nematode manipulates vector behavior through energy metabolic genes such as ATP1 and provides potential cues for vector manipulation by the pathogen on aging and longevity.

Sundaic giant tortoises (Manouria emys emys) are the largest chelonians in Asia. Classified as critically endangered, they are extremely rare throughout their range. The limited knowledge of their behavior and ecology hampers effective conservation initiatives. We integrated GPS tracking, behavioral observations, local ecological knowledge, resource selection functions, spatial distribution modeling, and landscape functional connectivity to assess key aspects of their food habits, movement patterns, and habitat relationships at local and broad scale in Sumatra, Indonesia. Sundaic giant tortoises were predominantly diurnal (93% of activities) and had a mean home range of 27.5 ha (±28.8 SD; N = 3 individuals, autocorrelated kernel density estimate). We identified 40 plant species from 20 families, including ferns, monocots, and dicots, consumed by the tortoises. They consumed the fruits of 30 of these plants, swallowing seeds as large as those of Durio and Artocarpus (>2 × 4 cm), indicating potential seed dispersal over distances exceeding 1 km. Habitat preference analysis at both local and island-wide scales showed a consistent preference for primary rainforests with steep slopes at moderate altitudes, and near rivers, mostly on the western side of the island. We identified 15 “priority areas,” that is, those with high habitat suitability but lacking formal protection. Among these, only one, Gunung Talang, lacked connectivity with other forest areas, prompting us to propose a wildlife corridor connecting it to Kerinci Seblat National Park. In addition, we argue that Sundaic giant tortoises hold potential for rewilding operations in Sumatra and other parts of their range, emphasizing the need for targeted conservation efforts.

Seed traits play a pivotal role in shaping rodent-mediated seed dispersal, a key process driving forest regeneration. However, disentangling the independent and interactive effects of physical (coat thickness), nutritional, and chemical (tannin) traits remains challenging due to their natural covariation. Using artificial seeds in enclosures, we quantified how these traits influence foraging decisions by Leopoldamys edwardsi, a dominant scatter-hoarding rodent in subtropical forests. Our results revealed a hierarchical order of trait importance: nutrient content > tannin content > coat thickness. High-nutrient seeds were preferentially consumed, while moderately nutrient-rich seeds (50% peanut powder) were most frequently scatter-hoarded, balancing immediate energy gain and long-term storage. Tannins exerted a dual effect: low concentrations (0.5%) enhanced consumption, likely due to reduced microbial decay, whereas high concentrations (7%) deterred both consumption and hoarding by impairing digestibility. Coat thickness had weaker effects but interacted with nutrients, as thin-coated, high-nutrient seeds were favored for both consumption and hoarding. Interactive effects highlighted a “benefit-first” decision framework, where rodents prioritize energy gain (nutrients), then modulate behavior to preserve benefits (tannins aiding storage), and finally account for handling costs (coat thickness). These findings illuminate coevolutionary dynamics between rodents and seeds, emphasizing how trait combinations shape mutualistic interactions critical for forest dynamics. Our study provides a mechanistic basis for predicting how shifts in seed traits may disrupt these interactions, with implications for ecosystem management.

Plant and fruit functional traits fundamentally structure mutualistic networks in forest ecosystems. However, it remains unclear how these traits affect the network structure in the coastal forests. Understanding the relationship between plant traits and network structure is crucial not only for fundamental ecology, but also for the effective conservation and management in the coastal forest ecosystems. Here, we examined avian–frugivory networks in the coastal forests of Dafeng, eastern China, by integrating key plant (height, canopy density, and fruit yield) and fruit traits (water content, crude fat, sugar, starch, and phenolics). The frugivory network exhibited a specialized and modular structure with significantly lower connectance and nestedness than null model expectations. Generalist species, particularly the light-vented bulbul (Pycnonotus sinensis), acted as the main forager in the network, interacting with all 12 plant species. The results of generalized additive models revealed complex nonlinear relationships between plant functional traits and network structure: fruit yield exhibited a threshold effect on species degree, while water content showed a unimodal effect. Crude fat and tannin content further influenced specialization through saturating and unimodal patterns, respectively. Overall, our study highlight that both structural and nutritional traits critically shape frugivory networks in coastal forests. Our findings also provide a trait-based framework for conservation of coastal forests, underscoring the need to preserve generalist frugivores and prioritize plant species with key functional traits to maintain ecosystem resilience.

Amphibian larvae consume variable diets in the wild, which can include tannin-rich plant material. Tannins are secondary metabolites that, when consumed, could have complex effects on herbivorous amphibian larvae, including altering their microbiome. Previous studies on the effects of dietary tannic acid on tadpoles were performed using laboratory water, largely devoid of natural microbes. Given that tadpoles acquire much of their gut microbiota from the aquatic environment, we sought to understand the effect of dietary tannins on tadpole size and the gut microbiome when animals were raised in natural pond water, supplying a diverse repertoire of microbes. We raised Green Frog (Lithobates clamitans) tadpoles in autoclaved (microbially depleted) or natural (microbially rich) pond water treatments for 4 weeks. Tadpoles were fed a control diet or a diet containing 2% tannic acid. Tadpoles raised in natural pond water had a greater body mass and length than those raised in autoclaved pond water, but dietary tannins had no effect on body size. Gut bacterial diversity was profiled using 16S rRNA sequencing. The gut microbiome from tadpoles raised in natural pond water was more diverse than that of tadpoles raised in autoclaved pond water. In general, dietary tannins caused a decrease in bacterial diversity and a net reduction in the relative abundance of potentially pathogenic bacterial genera in tadpoles raised in natural pond water but not autoclaved pond water. This study highlights the importance of replicating natural microbial contexts in captive experiments to better investigate biological interactions, such as plant–herbivore and host–microbe interactions.

The gut microbiome is crucial for animal health, yet the diversity of the critically endangered Chinese giant salamander's gut microbiota remains largely uncharacterized. In this study, we first conducted a comprehensive landscape survey of the gut microbiome of the Chinese giant salamander using 16S rRNA sequencing across a wide geographic range, identifying a distinct microbial cluster within its habitat. Subsequently, using shotgun metagenomes, we recovered 1518 metagenome-assembled genomes. Notably, 85% of the newly identified genomes could not be assigned to any known bacterial species, indicating a significant presence of novel taxa in Chinese giant salamander intestines. We observed substantial species-level variations in the gut microbiome across different age groups, with some novel species uniquely enriched in specific age populations. From the gut symbionts, we established a gene catalog comprising 3 278 107 non-redundant protein-coding genes, of which 7733 were annotated into recognized KEGG orthology groups. Additionally, we found that the gut microbiota of the Chinese giant salamander exhibits enhanced functional capacities explicitly in lipid metabolism and assimilatory sulfate reduction. Significant variations in the abundance of related enzyme-encoding genes across age groups suggest the unique roles of microbial metabolism in salamander health. By identifying microbial genomes and constructing an integrated gene catalog from metagenomic data, we significantly expand the resources available for research on the gut microbiome of the Chinese giant salamander, paving the way for further investigations into its ecological and health-related implications.

Personality can influence animals' competitive foraging behavior. The state–behavior feedback theory suggests that these personality-driven variations may be affected by physiological states. However, the impact of personality on competitive foraging behavior within a species, as well as the physiological states associated with these variations in personality-driven foraging behavior, remains unclear. In this study, we investigated changes in foraging behavior between bold and shy Mongolian gerbils across three distinct contexts: (1) non-competitive foraging contexts, (2) a competition-introduced context at a feeding site, and (3) competitor relocation to another feeding site. We also explored the potential hormonal and energy balance factors that may influence these behavioral variations. Our results revealed that bold gerbils exhibited a consistently greater tendency to compete in two competitive contexts. Shy gerbils opted for lower-cost and more easily obtainable food resources in the competition-introduced context but displayed a similarly high tendency to compete during the competitor transfer context. Although we did not find a significant difference in fecal production, digestibility, basal metabolic rate, or blood corticosterone levels between bold and shy gerbils, bolder gerbils exhibited lower body mass and daily energy expenditure but higher food intake. Our findings indicate that Mongolian gerbils exhibited personality-driven competitive foraging strategies during intraspecific competition, which may be influenced more by differences in energy allocation than by competition pressure. This study provides empirical evidence to enhance our understanding of the mechanisms underlying personality variation in behavior and the personality-driven behavioral plasticity based on the state-behavior feedback framework.

Social hierarchy is a fundamental aspect of social behavior in animals, influencing individual health and well-being. This study investigated the role of serotonin (5-HT) neurons in the dorsal raphe (DR) nucleus and their projections to the central amygdala (CeA) in regulating social dominance in male mice. We first observed elevated c-Fos expression in 5-HT neurons of subordinate mice, indicating heightened neuronal activity during social competition. Using chemogenetic approaches, we found that activation of DR 5-HT neurons and DR^5-HT-CeA projections significantly reduced the social rank of dominant individuals, while inhibition had negligible effects on the subordinates. Additionally, activation of the DR^5-HT-CeA circuit induced anxiety-like behaviors in dominant mice, as evidenced by reduced exploration in the open-field test. Pharmacological blockade of 5-HT1A receptors in the CeA reversed the effects of chemogenetic activation, highlighting the involvement of 5-HT1A receptors in this process. These findings underscore the critical role of the DR^5-HT-CeA circuit in modulating social dominance and suggest that 5-HT1A receptors in the CeA play a pivotal regulatory role. Overall, the current study provides new insights into the neural mechanisms underlying social hierarchy, which is closely related to our health and welfare.

The European hedgehog (Erinaceus europaeus) is currently designated as near threatened by the International Union for the Conservation of Nature. Threats include reduced prey availability, emerging pathogens, and environmental contaminants. Improving knowledge of food preferences and the role of diet in disease and exposure to toxins is important for its conservation. We used fecal DNA metabarcoding to characterize the diet of 209 hedgehogs in Europe. Stylommatophora (slugs and snails) made up the most frequent order in the hedgehog diet (found in 92% of individuals), followed by Haplotaxida (earthworms; 54%), Coleoptera (beetles; 54%), Lepidoptera (moths and butterflies; 48%), and Orthoptera (grasshoppers, locusts, and crickets; 54%). Presumed anthropogenic food, primarily in the form of pet food, was consumed by 29% of hedgehogs. We found no relation between diet and infection with pathogens (Corynebacterium ulcerans or circovirus). However, diet richness was negatively correlated with hepatic concentration in brodifacoum, a widely used rodenticide. Moreover, the relative abundance of Stylommatophora in the hedgehog diet was positively correlated with their hepatic concentration of zinc. Generally, Stylommatophora consumption was most frequent at locations of highest cumulated rainfall. The near-ubiquity of invasive Spanish slugs (Arion vulgaris; found in 80% of individuals) in the diet is concerning for hedgehog conservation, since this species is a known vector of lungworm parasites and accumulates high concentrations of environmental contaminants, such as zinc and rodenticides. Overall, this study provides a novel, high-resolution view of hedgehog diet composition and highlights the need for further research on the role of terrestrial gastropods as toxicant vectors through food webs.

The visual systems of subterranean mammals often exhibit significant physiological and structural modifications due to light-restricted habitats, as widely reported. However, as subterranean species with a relatively short divergence time from their above-ground relatives, Mandarin voles (Lasiopodomys mandarinus) have been the subject of limited research regarding their visual characteristics, and potential parallels in their visual system's environment-induced changes remain unclear. We systematically analyzed the visual system of Mandarin voles, using their above-ground sister species Brandt's voles (Lasiopodomys brandtii) and standard laboratory mice (C57BL/6J, Mus musculus) as reference controls. Behavioral results showed that Mandarin voles exhibit reduced visual function, including visual acuity (<0.02 cycles/degree) and depth perception. Anatomical examinations revealed structural remodeling in the retina and dorsal lateral geniculate nucleus (dLGN), characterized by a relative decrease in rods and an increase in cones within the retina compared to C57BL/6J mice, along with dLGN showing reduced volume but increased mature neuron density and connectivity compared to Brandt's voles and C57BL/6J mice. Notably, the primary visual cortex (V1) retained a conserved structure. An evolutionary dynamic analysis of vision-related genes identified pseudogenization of genes and contraction of gene families associated with retinol metabolism, crystallin proteins, signal transduction, and retinal structure. These findings suggest that Mandarin voles exhibited visual functional degeneration, structural remodeling of visual pathways, and pseudogenization of vision-related genes compared to surface-dwelling species. This study systematically characterized the visual features of Mandarin voles, providing novel experimental evidence for understanding environmental adaptation in mammalian visual systems.

Hibernation involves complex physiological adaptations enabling animals to survive extreme conditions. During hibernation, body temperature, metabolic rate, and heart rate change significantly but are quickly restored upon arousal. Despite extensive research, the underlying mechanisms remain unclear. This study used proteomics to examine cardiac and hepatic protein levels in food-hoarding hibernator Siberian chipmunk (Tamias sibiricus) during torpor and arousal. Results show that, unlike the fat-storing hibernators, the liver of chipmunks maintains glucose, lipid, and bile acid synthesis throughout hibernation due to changes in proteins like GALE, SLC2A3, GSK-3α, HMGCS2, ACAT2, and AMACR. In contrast, reduced mitochondrial autophagy (PINK1 and PARKIN) and enhanced anti-apoptotic mechanisms (TFRC, WFS1, and NDRG1) help maintain energy balance in the heart. These findings provide new insights into cardio-protection in food-hoarding hibernators and improve our understanding of adaptive mechanisms in mammalian hibernators.

Sterility control is one of the key tools for regulating pest rodent population density. An in-depth analysis of the molecular mechanism of sterility caused by control agents is of great significance for further exploration of novel sterility controls and the development of alternative drugs. In this study, male plateau zokors (Eospalax baileyi) in the breeding period were tested to explore the molecular mechanism of quinestrol-induced sterility. We used RNA-seq technology to investigate key genes and signaling pathways associated with the inhibition of testicular development and spermatogenesis, and validated these findings through qPCR. The findings indicated that in plateau zokors treated with quinestrol, 420 genes were down-regulated and 127 genes were up-regulated. Notch3, Ppp2r3c, Lipe, Il1b, and Tlr2 are the potential new targets for quinestrol to affect testicular development in plateau zokors. Gene ontology (GO) analysis showed that DEGs were enriched in the inflammatory response, positive regulation of ERK1 and ERK2 cascades, and positive regulation of MAPK cascades. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that DEGs were enriched in pathways such as metabolism of xenobiotics by cytochrome P450. GSEA analysis revealed that treatment with quinestrol induced pathway changes related to the positive regulation of the ERK1 and ERK2 cascades and the positive regulation of PI3K/AKT signaling in plateau zokors. Quinestrol influences the ERK1/2 signaling pathway within the MAPK cascade in spermatogonia of plateau zokor testes via the GPER1 receptor, inducing oxidative stress and resulting in male infertility.

Understanding the mechanisms shaping biodiversity distribution patterns is essential in ecology, and species distributions are closely influenced by environmental factors. Previous studies have often focused on taxonomic levels, potentially overlooking important within-group ecological variations. Anurans, with six distinct ecotypes, each occupying unique habitats, serve as an ideal model to examine how environmental factors shape these ecotype-specific distributions. Here, we investigated the global distribution and environmental determinants of anuran ecotypes to reveal diversity patterns, assess their contributions to overall anuran richness, and identify key environmental drivers. Using microhabitat and geographic data from 6088 anuran species, we mapped the richness and relative richness of each ecotype and evaluated the correlation between ecotype distributions and overall anuran diversity. We further used a random forest model to analyze the impact of environmental factors on the distribution patterns of each ecotype. The results showed significant diversity and distributional differences across ecotypes. Terrestrial and arboreal species, comprising 38.44% and 41.19% of total richness, respectively, contributed strongly to anuran diversity patterns (correlation up to 0.96), while other ecotypes showed weaker correlations. The impacts of environmental factors varied across ecotypes and even had contrasting effects among them. Our findings underscore the importance of accounting for ecotype differences within taxa to accurately understand biodiversity distribution patterns, as environmental influences on anuran diversity are strongly ecotype-dependent.