Journal of Zoology

Quantification of faecal glucocorticoid metabolites (fGCMs) is a popular non‐invasive technique for monitoring wildlife's response to stressors, demanding an understanding of the stability of fGCM concentrations post‐defaecation to ensure comparability of determined fGCM values across samples. To provide species‐specific recommendations for the duration within which sampling can take place, we measured the rate at which the fGCM concentrations of nine different species changed throughout a 7‐day period post‐defaecation. In this study, we explored the temporal dynamics of fGCM concentrations in nine species across three feeding classes (ruminants, hindgut fermenters and carnivores): impala (Aepyceros melampus), giraffe (Giraffa camelopardalis), blue wildebeest (Connochaetes taurinus), plains zebra (Equus quagga), African elephant (Loxodonta africana), white rhino (Ceratotherium simum), cheetah (Acinonyx jubatus), spotted hyena (Crocuta crocuta) and leopard (Panthera pardus). Utilizing enzyme immunoassays already established for each of the focal species, we identified broader feeding class‐specific patterns. All herbivores exhibited a significant decrease in fGCM concentrations over time, starting from 6 h (impala) to 48 h (giraffe, blue wildebeest, white rhino and African elephant) post‐defaecation. For carnivores, concentrations remained fairly comparable for 12–24 h, after which fGCM concentrations either decreased (spotted hyena), increased (leopard) or remained stable (cheetah), with notable variation in triplicate concentrations (cheetah and leopard). These findings offer insights into scheduling faecal sampling for endocrine monitoring, particularly from free‐roaming wildlife, to ensure comparability of determined hormone metabolite concentrations. Furthermore, the species‐specific variation in fGCM concentration post‐defaecation demonstrated in this study underlines the necessity to investigate every new species to ensure accurate and comparable results. Future studies ought to investigate how the mass of collected material, sex and drying methodologies affect the measurement of fGCMs post‐defaecation.

Endemic rodents constitute 19% of Australian terrestrial mammal species and this proportion is higher in arid zones and the north. We report substantial genetic diversity and population structure in the common rock‐rat, a saxicoline murid whose range extends across northern Australia and into the continent's interior. Samples of 686 individuals from 68 locations, encompassing the western half of the species' range, provide one of the most geographically and numerically extensive genetic studies of an Australian rodent. The Great Sandy Desert, a prominent feature over the last 0.5 my bp acts as a significant barrier to gene flow. Continental islands, formed during the past 10 000 years following the end of the most recent Pleistocene glacial maximum, have populations with lower heterozygosity and marked differentiation from each other and the adjacent mainland. On the mainland, despite considerable differentiation between locations, there is only weak evidence for isolation by distance and where it occurs it is associated with drainage basins. In the Pilbara, analyses of genetic structure within localized sub‐locations, just a few kilometres apart, indicate considerable variation between them (FST) and inbreeding within (FIS). We interpret this in the context of cyclonic and other extreme rainfall events that occur episodically, leading to boom‐bust population cycles. Populations decline into refugia of isolated rock patches during extended periods of poor resources with consequent low genetic diversity (He) and large differentiation from others. Populations that irrupt after major episodic rainfall increases resource states, have a more extensive distribution with greater heterozygosity because of gene flow between previously isolated refugia and less differentiation between the locations. These observations have conservation significance for threatened congeneric species and other Australian arid rodents by demonstrating, in this common exemplar, the reduced evolutionary potential imposed by both transient isolation due to climatic variation and longer term disruptions by geographic barriers.

Investigations on resource use by predators are important for understanding the mechanisms of biological coexistence. Although time, habitat, and diet are considered the three major dimensions for niche partitioning, studies that comprehensively investigate these dimensions in predator guilds are limited. Snakes are one of the predators whose populations have been reported to be declining worldwide. While diet has been considered as a fundamental variable that allows snakes to coexist, the importance of spatiotemporal resources has also been noted especially in temperate regions. To clarify the coexistence mechanisms of terrestrial snakes, we assessed the niche partitioning patterns of snakes on Sado Island, a Japanese island rich in snake species, from the perspectives of spatiotemporal and dietary resources. Specifically, we investigated the daily and seasonal occurrences as temporal niches, landscape‐level distribution as a spatial niche, and stomach content as a dietary niche. We found that niche partitioning in all three major resources occurred among snake species on the island. Daily occurrence was partitioned into three groups: completely diurnal, nocturnal, and active during both periods. Seasonal occurrence was partitioned into three groups: widely active from spring to autumn, mainly active in summer, and mainly active in autumn. Distribution was partitioned into two groups: mainly distributed in lowlands and distributed even in mountainous areas. Food habits were partitioned into three groups: rodents, frogs, and earthworms as main prey, respectively. Our results provide empirical evidence that snakes can coexist through multidimensional niche partitioning, and that spatiotemporal resources are also an important force in terrestrial snake coexistence. Furthermore, we suggest that snakes on the island coexist through subtle differences along the three major niche axes, and that conservation of a variety of niches, rather than a single niche, will increase the species diversity of local snakes.

When hermit crabs recognize the risk of predation, they generally hide inside their shells or flee from the area, and little is known about their escape behaviors after being captured by a predator. We discovered that the hermit crab Pagurus filholi abandons its shell and attempts to flee when captured by the predatory crab Charybdis japonica, and we examined the effectiveness of this behavior in laboratory experiments. We fed captive C. japonica with P. filholi occupying gastropod shells. When the C. japonica could not break the shell even a little, it gave up and the P. filholi neither abandoned its shell nor was eaten. However, when the predator succeeded in partially breaking the shell, the hermit crab often abandoned the shell, and when it did so, it often survived. Once the predator had completely broken the shell open (implying that the shell has been broken to the extent that it no longer has any structural integrity), all hermit crabs that remained back in the shell (22/22) were consumed, and those that abandoned the shell were also often consumed (3/5). Therefore, hermit crabs do not need to abandon their shells if a predator is unable to break the shell even slightly, but if a predator begins to break the shell, they have a better chance of survival if they abandon their shells at an early stage.

The aggregation of conspecifics in the invasive shrimp Palaemon macrodactylus could be driven by either patchy environmental conditions or conspecific attraction. This study aimed to determine whether the observed grouped distribution in natural conditions results from gregarious behavior and the type of cue used by shrimp to locate conspecifics. Four experiments were conducted during the non‐reproductive season in which a focal shrimp was given the choice between a zone with cues of conspecifics or an empty zone. The cues permitted in each experiment encompassed visual and chemical cues, exclusively visual cues, exclusively chemical cues and a control devoid of any visual or chemical cues. The results indicated that focal shrimps exhibited a preference for conspecific zones when exposed to chemical cues alone or in combination with visual cues. However, visual cues alone were insufficient to induce grouping with their peers. The value of this trait is discussed along with other behavioral characteristics of the species as a possible explanation for its success as an invader.

Marine iguanas occasionally face severe food shortages because of algal dieback during El Niño events. Research on their adaptations to these periods has highlighted their unique ability to shrink in body length, which reduces their energetic needs. Additional mechanisms, like sustaining lower body temperatures and metabolic rates, could potentially also lower energy consumption, but have never been examined. We measured 665 iguanas over an 11‐year period including three El Niño events, and examined how heart rates (a proxy for metabolic rates) and body temperatures change with sea‐surface temperature oscillations (Oceanic Niño Index, ONI). Heart rate (adjusting for body size, temperature, season, and study site) was negatively correlated with ONI and lower during El Niño, whereas the adjusted body temperature did not correlate with ONI or differ between El Niño and other periods. We therefore hypothesize that marine iguanas can depress their metabolic rates in response to the harsh conditions, an adaptation that is complementary to shrinking and may further enhance their survival through periods of limited food. Direct metabolic measurements are needed to test this hypothesis.

Barriers faced by underrepresented groups in academia have increasingly formed the basis of serious discussion, consideration, and policies, recently (in the UK) under the mantle of equality, diversity, and inclusivity (EDI). While such recognition has not solved the challenges encountered by, for instance, women and ethnic minorities, it has at least ensured that consideration of such issues is becoming a normal part of policy and practice. One underrepresented group in academia is low socioeconomic status (working class) backgrounds, a characteristic that intersects widely with other more commonly considered EDI groups. However, socioeconomic status is not a legally protected characteristic in the UK, which has resulted in it receiving less attention in terms of consideration of the barriers it imposes and possible mitigations needed. Moreover, unlike often more salient EDI characteristics such as gender and ethnicity, outward‐facing cues of socioeconomic status are less visible at a glance, although they are often detectable in more subtle or indirect ways. Coupled with the attempts many working‐class academics make to ‘mask’ cues of their background, this creates a situation whereby low socioeconomic status is a ‘hidden’ barrier that commonly remains unrecognised and unaddressed throughout much of academia. Here, we provide an overview of the challenges faced by working‐class academic scientists based partly on the literature, which is currently limited, and partly from the experiences of our diverse working‐class authorship team. In doing so, we hope to bring greater awareness of working‐class backgrounds to the table in EDI discussions, and we provide suggestions for future research on and mitigation of the challenges faced by academic scientists from low socioeconomic status backgrounds.

The history of Homo sapiens is studded with many events promoting relationships with wild animals changing their evolutionary path or impacting their adaptation. Artificial selection is recognized as the product of planned actions aimed to annex useful species into the anthropic niche. However, the effect of humans on animal evolutionary trajectories is diversified and cannot be assigned to a single driver. We characterized the genomes of feral pigs managed by different traditional husbandry practices to infer about the combining effect of artificial and natural selection. Whole genome characterization showed a clear distinctiveness of Sardinian wild boars (Sus scrofa) from free‐range pig and domestic pig (Sus domesticus) populations, while Eurasian wild boars and hybrids are closely related, also in agreement with allelic frequency. In the Southern Italy system, we found 7 SNPs putatively under selection, associated with genomic regions including genes mainly involved in body weight control and feeding behavior, muscle growth and development, and adipocyte proliferation. Considering Sardinian wild boar and free‐range pigs, over 3000 SNPs were found putatively under selection, and the genomic regions in which these SNPs fall include genes linked mainly to litter size and number of teats. The screening of genomic variability was useful to characterize feral pigs and wild boars from Southern Italy and Sardinia and the relationships between them, highlighting the effect of a peculiar artificial selection that modulates its weightiness due to the concomitant natural selection. In particular, the traditional Sardinian pig husbandry seems to act pushing down gene flow towards wild boar while favoring adaptations to life in the wild, creating a unique genetic pattern in free‐range pigs, different both from the domestic and the wild genetic makeup. Our contribution opens up a discussion on the current European policy for the management of free‐range pigs, the effective conservation actions for diversity in Suidae forms and their consequent impacts on biodiversity.

Large carnivores such as leopards (Panthera pardus) experience continuing threats from habitat loss and fragmentation, depletion of prey populations, and retaliatory killing following conflicts with humans. We aimed to identify factors affecting leopard occupancy and temporal overlap between leopards and tigers (P. tigris), their major prey, and human activities in the Parsa‐Koshi Complex (PKC), Nepal. We deployed 154 cameras for 21 days each along wildlife trails throughout PKC during December 2022–March 2023. We found low leopard occupancy (0.17 ± 0.04) in PKC, with greater occupancy rates within protected areas, particularly in Parsa National Park and its buffer zone. Human (63.10 ± 23) and livestock (36.46 ± 102) detections were higher across the PKC. Leopard occupancy was positively associated with the presence of tigers and prey. Temporal overlap was moderately high between leopards and tigers, as well as between leopards and their prey. Our research suggests that coexistence between leopards and tigers is likely largely facilitated by higher prey availability, which may reduce competition. Further, we demonstrate that maintaining forest cohesion can improve habitat for leopards. Intensifying use of agricultural areas could reduce forest fragmentation and increase leopard habitat overall, in turn reducing leopard depredation of livestock and improving leopard‐human co‐existence and conservation.

Nature‐based tourism in protected areas can benefit millions of people, generating significant economic income. However, tourism can also have negative impacts on the environment and wildlife. The emergence of the COVID‐19 pandemic led to the closure of cities and towns, bringing substantial disruption to various human activities and providing an opportunity to assess the impact of reduced tourism activity from the general level. In this study, we assessed the association between tourism and guanaco (Lama guanicoe) activity patterns in Ischigualasto Provincial Park across two contrasting periods: pre‐pandemic and pandemic during the COVID‐19 outbreak. The different roads in the area were used as a proxy of tourism activity, and comparisons of activity patterns of guanaco between the roads were made, taking into account both periods. Based on camera‐trapping data, we analyzed the daily activity patterns of the species, as well as whether there was a change in activity toward night hours. We found that guanacos changed their activity patterns in response to human tourism activities and increased their nocturnal activity in places with high tourist activity in pre‐pandemic periods; however, we found no such effects during the pandemic when tourist pressure was low. These results are vital for the area's management aimed at conserving the species since, currently, after the pandemic, tourism activities have been resumed, and the number of visitors to Ischigualasto Provincial Park has grown exponentially.

Scent marking at latrines is used by a variety of mammals for communicating an individual's reproductive status, social rank, or territory. Both brown hyenas (Parahyaena brunnea) and spotted hyenas (Crocuta crocuta) make use of latrines. Previous research showed that the presence of the more dominant spotted hyena negatively affects the presence of brown hyena. As both species rarely occur in the same area, little is known about the temporal patterns of using shared latrine sites. Central Tuli, Botswana, is home to one of the highest densities of both spotted and brown hyena in southern Africa. We conducted a camera trap study and monthly scat counts for monitoring the visitation and defecation rates of brown and spotted hyenas at shared latrines to examine the temporal patterns of latrine use. Our results showed seasonal differences in latrine use, with lower visitation and defecation rates for both species during the wet season. We found high temporal overlap in latrine use for the two species. However, the time interval between consecutive spotted – brown hyena visits was larger than for consecutive brown hyena–spotted hyena and consecutive conspecific visits during the dry season, suggesting that brown hyena seem to show fine‐scale temporal avoidance of spotted hyenas at shared latrine sites. The presence of spotted hyenas, or other large carnivores, could possibly inhibit intraspecific communication for brown hyena at shared latrine sites.

With the increasing frequency and intensity of heatwaves due to climate change, the survival and reproductive success of mammals could be under significant threat. However, the specific effects of these environmental stressors on mammalian reproductive fitness remain insufficiently explored. This study investigates the impact of a simulated heatwave on male fertility indices in two African rodent species: the mesic four‐striped field mouse (Rhabdomys dilectus) and the Namaqua rock mouse (Micaelamys namaquensis) during the breeding season. We measured key indicators of male fertility, including testes mass, testes volume, seminiferous tubule diameter, the presence of sperm, and plasma testosterone levels. Our findings reveal that both species experienced significant effects on male fertility indices, with the smaller R. dilectus showing a decline in all fertility indices following a simulated heatwave. These results suggest that the projected increase in heatwave events may compromise the reproductive success of small mammals, potentially leading to population declines. Finally, this study highlights the need for focused studies on the effect of heatwaves on long‐term reproductive success in both males and females.

Human impacts on the environment and wildlife populations are increasing globally, threatening thousands of species with extinction. While wildlife‐based tourism is beneficial for educating tourists, generating income for conservation efforts, and providing local employment, more information is needed to understand how this industry may impact wildlife. In this study, we used motion‐activated cameras at 12 waterholes on a private game reserve in northern Namibia to determine if the presence of humans and permanent infrastructure affected mammal visits by examining their (1) number of visits, (2) time spent, and (3) diel activity patterns. Our results revealed no differences in the number of visits based on human presence for any of the 17 mammal species studied. However, giraffes (Giraffe camelopardalis) spent more time at waterholes before observer presence compared to during. Additionally, several species changed diel activity patterns when human observers were present. Notably, several carnivore and ungulate species increased overlap in their activity patterns during periods while humans were present relative to when humans were absent. These modifications of mammal temporal activity patterns due to human presence could eventually lead to changes in community structure and trophic dynamics because of altered predator–prey interactions. As humans continue to expand into wildlife habitats, and wildlife‐based tourism increases globally, it is imperative that we fully understand the effects of anthropogenic pressures on mammal behavior. Monitoring of wildlife behavioral changes in response to human activity is crucial to further develop wildlife tourism opportunities in a way that optimizes the impact of conservation goals.

Small mammal populations fluctuate significantly in abundance over time, affecting the entire food web. However, changes in their occupancy across a landscape receive less attention. While habitat features are relevant for some predators, diet specialization and prey distribution and abundance might play an important role in shaping predator populations. Using a multi‐season occupancy analysis, we examined the spatio‐temporal patterns of Mediterranean mesocarnivores—common genet, stone marten and red fox—focusing on the factors that influence their occupancy dynamics, particularly small mammal occupancy as a prey resource. Data was collected from December 2020 to May 2021 in the Sant Llorenç del Munt i l'Obac Natural Park using a camera‐trap grid. We analysed small mammal occupancy dynamics and used these as covariates in predator occupancy models to explore predator–prey relationships. Additionally, we included the occurrence of each carnivore as a predictor for interspecific analysis, and kernel density functions were used to assess daily activity overlaps. Results showed that interspecific competition significantly affected mesocarnivore occupancy, as genet occupancy was negatively correlated with the red fox occupancy. Although prey occurrence did not influence mesocarnivore occupancy, it did affect detectability, with genet and stone marten detectability being positively related to small mammal presence and high daily activity overlap between predators and prey. This suggests that mesopredators respond rapidly to prey abundance, highlighting the intricate temporal dependence between predator activity and prey occupancy. Dynamic occupancy and activity models provide a deeper understanding of predator–prey relationships at the local scale.

The evolution and ecomorphology of rodent craniomandibular apparatus have been extensively studied at a broad spatial scale. However, the question of how phenotypes and developmental instability interact with ecological pressures in human‐modified landscapes has been less explored. In this study, we test the influence of evolutionary history, diet, and habitat use on skull and mandible shape variation within a rodent community composed of eight cricetid species from an agroecosystem in central Argentina. We used geometric morphometrics, phylogenetic relationships, and ecological specializations in diet and habitat use to test the interplay between these factors. Our results indicated a strong phylogenetic signal for the symmetric components of the skull shape, but not for the mandible or asymmetric shapes. The strict insectivorous Oxymycterus rufus was the most phenotypically diverged within the rodent community. In general, more generalist species, both in terms of diet and habitat use, presented more phenotypic disparity (diversity) than specialists (e.g., strict insectivorous and natural and semi‐natural specialists) in craniomandibular shape variation. Dietary generalists and non‐strict granivores presented a tendency to show more skull asymmetric variation than non‐strict insectivores. These results suggest that generalist species exhibit higher levels of variation compared to specialist species, likely due to their wider range of responses to environmental stress. In cricetid species with similar ecological preferences, coexistence may thus be facilitated by morphological partitioning and developmental instability canalization based on dietary differences.

Color polymorphisms in lizards are maintained by complex interactions between environmental factors, genetics, and physiological traits (e.g., immunity) that can differ among morphs. Here, we investigated the relationship between mite load, throat coloration (orange, yellow, and white), and cell‐mediated immune responsiveness (CMI) in the Atlas day gecko, Quedenfeldtia trachyblepharus (Boettger, 1874) during its post‐mating period. We also evaluated the relationship between the patterns of infestation by ectoparasites and sex, throat color, and host size. The prevalence and intensity of infestation by mites did not differ by sex, host body length, or throat color. Furthermore, there was no significant relationship with host body condition. The CMI was related to sex and lizard body size (SVL). Additionally, there was a positive correlation between the intensity of infestation and the CMI response of the gecko hosts. Likewise, there was a significant positive correlation between CMI and the scaled mass index (SMi) of the lizards. In addition, geckos with broken tails had a significantly higher CMI than those with regenerated or intact tails. Moreover, CMI differed significantly among morphs; orange morphs had a higher immune response than yellow one, while the white individuals presented the lowest response. Thus, CMI is morph‐specific in this gecko, suggesting that this immunological trait could play a determinant role in maintaining throat color polymorphism in this species.

Certain parasites can manipulate their hosts to enhance their own fitness and transmission success. Rhizocephalan barnacles are a notable example, inducing significant changes in their crustacean host's morphology, physiology, and behaviour. Until recently, it was believed that the spider crab Scyra aff. ferox is parasitized by a single species Sacculina pilosella in the Sea of Japan. However, previous molecular studies have revealed a complex of unrelated species, Sacculina pugettiae (fam. Sacculinidae) and Parasacculina pilosella (fam. Polyascidae). These rhizocephalans can even parasitize one host specimen simultaneously. Here, we investigated the interaction of S. pugettiae and P. pilosella with the nervous system of their common host. Species were identified based on receptacle morphology, with further validation through 18S gene phylogenetic analysis. The parasites interacted differently with the host nervous system: S. pugettiae had goblet‐shaped organs in the ganglion periphery, while P. pilosella lacked these structures, instead possessing numerous neuropil rootlets. In case of simultaneous infection, both goblet‐shaped organs and neuropil rootlets were present. Histochemistry revealed the presence of muscular rosettes in the rootlets of both species, suggesting a similar organization of the muscular system despite phylogenetic differences. Scanning electron microscopy confirmed the presence of host cell projections enveloping the rootlets. This study provides insights into the morphological features of rhizocephalan‐decapod interaction and highlights differences in their interaction with host nervous tissue between families. Our results also confirmed the loss of the goblet‐shaped organs in Polyascidae.

Human‐wildlife conflicts have increased and are particularly acute when predators are involved. A frequent source of conflict is some people's misbeliefs related to the alleged impact of predators on game species and livestock. In this context, quantifying the impact of expanding predators on their prey can be useful in designing conflict mitigation strategies. We estimated the predation impact of the Egyptian mongoose (Herpestes ichneumon), an expanding mesocarnivore in southwestern Europe, on European rabbit (Oryctolagus cuniculus) and red‐legged partridge (Alectoris rufa) populations, two declining prey species highly valued by hunters. We estimated mongoose densities in three areas of central Spain through live capture, GPS/VHF tagging, camera‐trapping and spatial mark‐resight models. Rabbit and partridge densities were estimated through transect counts and distance sampling. We quantified the mongoose diet by scat analysis. Finally, we compared the number of individuals consumed by the predator population with the estimated total prey populations. European rabbits were the most important mongoose food in two of the study areas, whereas red‐legged partridges were rarely consumed in all the areas. Rabbit density varied widely among study areas (14.0–881.4 rabbits/km²), while partridge density was low in all the areas (2.3–6.9 partridges/km2). The predation impact on rabbits was low in the area with the highest rabbit density (1.9–3.8% of estimated population) and higher (5.6–29%) in the other areas. In contrast, the predation impact on partridge populations was low (<9%) in all the study areas. This is the first study that estimates the Egyptian mongoose impact on small‐game species, a necessary step to deal with the conflicts over the management of this expanding species. The study of predation impact may contribute to the effective management of human‐wildlife conflicts involving predators, by improving the understanding of where additional management may take place to protect prey species or deter predator populations.

Hair offers a non‐invasive way to assess mercury exposure in diverse species, but variable and poorly understood molt patterns in wildlife may hamper the interpretation of tracer levels in hair. The reliability of using hair to precisely assess internal mercury burden, thus, varies across species, but few studies have assessed the reliability of using claw. Claws grow continuously, and growth rate may be easier to monitor than molt patterns. We quantified total mercury concentration (THg) in internal and keratinous tissues of 55 red foxes (Vulpes vulpes) legally harvested near Arctic tree line in Canada in winter (i.e., when mobility and opportunistic foraging are maximal) to compare the performance of hair and claw in predicting internal mercury burden, and examine the overall capacity of THg in keratinous tissues to predict internal THg at low exposure. Red foxes are widespread, occur at high densities and occupy a high trophic position, and thus could be a good sentinel species for monitoring mercury in the less‐studied terrestrial food webs. We found generally low levels of THg in all fox tissues (range: 0.06 mg kg⁻¹ in brain to 1.13 mg kg⁻¹ in hair) indicating overall low contamination of this low‐Arctic terrestrial food web. Relationships between THg of diverse internal organs were strong, but THg in both claws and hair were poor predictors of THg in internal organs. We thus advise caution when interpreting mercury levels in keratinous tissues of highly mobile species, as they may over‐ or underestimate the overall levels of exposure of a population because of non‐continuous or seasonal growth. Adding a time component using segmental analysis of continuously growing keratinous tissues, or associating multiple tissues reflecting diverse timeframes and physiological processes, may offer a more accurate and complete understanding of toxicological risks.

The great snipe Gallinago media, as a long‐distant migrant wintering in Africa, faces the challenge of accumulating sufficient energy reserves before departing from European breeding grounds. Despite possible trade‐offs in resource allocation, this species additionally initiates moult of flight feathers before southward migration. Here, we discuss the strategy of flight feather moult and fuelling for female and male great snipes from the Eastern European lowland population, exploring their scheduling constrained by the timing of breeding and departure. We found significant intersexual differences in both moult initiation date and the speed of moult. Males start flight feather replacement more than 2 weeks earlier and moult at a faster rate compared to females. However, neither sex completed this process on breeding grounds before the migration, as late in the season all males and half of the females had suspended their primary moult, with the remaining females not moulted at all. Moult of secondaries rarely occurred in the studied population. We observed non‐linear energetic stores gain in the studied period, where both sexes maintained stable and low energy stores until the end of July, coinciding with the primary moulting period. Subsequently, there was an increase in energy stores of approximately 1% of the lean body mass per day, indicating a shift towards fuelling for migratory flight. The overlap between stages of stable and low energy stores and moulting suggests a resource allocation towards feather growth before initiating fuelling. Besides limiting a trade‐off in resource allocation, this strategy may also contribute to minimizing predation risk, as both increased body mass and missing flight feathers may impair flight. Our study describes moult strategy in great snipe conducted on their breeding grounds, highlighting intersexual differences likely resulting from different parental duties of males and females of this lekking species.

Autotomy in animals, the voluntary loss of a body part at a specific location, is a widespread behaviour observed across various groups. This mechanism provides several advantages, such as predator evasion, escape from entrapments, and even reduced injury costs from agonistic interactions. Lizards display tail autotomy in response to predation and intraspecific aggression. Moreover, it is common for these reptiles to have sexually dimorphic traits, such as colouration and body size, which may influence predation risk and consequently their antipredatory strategies. This study focuses on the Achala copper lizard (Pristidactylus achalensis) which inhabits an isolated highland ecosystem in central Argentina. This species is an ideal study model due to its territorial and aggressive behaviour, high intraspecific competition and sexual dichromatism. The aims of this study were to determine the influence of sex and body size on the occurrence of tail autotomy in P. achalensis. Additionally, we assessed the cost of autotomy by analysing the distance between the vent and the tail cut. Furthermore, we investigated the possibility of repeated tail autotomy by a single individual. Our results showed that in P. achalensis, sex and body size interacted significantly resulting in different patterns of tail autotomy. In females, the frequency of autotomy increased gradually with body size, whereas in males it increased more abruptly and reached its maximum frequency at smaller body sizes than in females. Males presented higher autotomy frequencies than females, likely because they are more likely to be perceived by avian predators than cryptic females. The findings of this study contribute to broadening the knowledge of lizard behaviour, shedding light on the complex interplay between predation, intraspecific competition and reproductive dynamics in this unique species.

Several animals present ornamental colouration which acts as signals in sexual or other social contexts by indicating some trait of the bearer. This colouration is often present only in one sex and may be produced by a varied combination of structural elements and several pigments. Given that colours may be produced in different ways, the traits the colouration is indicating, and the costs or trade?offs associated, may differ according to the colour and the species studied. Here, I study a dark ventral colouration present in males of the gecko Quedenfeldtia trachyblepharus, a high‐altitude, semi‐colonial lizard endemic to the High Atlas in North Africa. I tested for the correlation between the extension of the dark colouration and several morphological traits (body size, head size and limb length) in the gecko, as well as parasitism by mites and age. No relationship was found between dark colouration and parasitism, age and limb length, but the extension of the dark colouration was positively correlated with head size controlled for body size. Given that head size is usually a good indicator of fighting capacity, and this gecko shows a strong social structure, the findings suggest that the dark colouration is used in agonistic encounters among males, allowing for evaluation of the fighting capacity of the rivals.

Anthropogenic landscape change due to urbanization, agriculture, and resource extraction results in barriers within the landscape. Artificial structures such as roads, fences, levees, and dams limit the movement of some species and further fragment residual habitat. In this study, we investigated the ability of Eastern long‐necked turtles (Chelodina longicollis) to cross various terrestrial obstacles commonly encountered throughout their habitat. We tested two types of fences (chicken wire and hinged joint exclusion fencing) commonly used in agricultural systems and three sizes of rocks (gravel, cobbles, and boulders) often used for road construction, erosion control, and waterway stabilization. We examined the success rates of turtles in crossing obstacles, the effect of fatigue on crossing attempts, and the impact of individual boldness on movement behaviour. Turtles had high success rates in crossing gravel (85.4%), cobbles (86%), boulders (73.3%) and hinged joint exclusion fencing (94.7%). Turtles did not successfully cross chicken wire fencing (0%) despite 276 attempts. A significant fatigue effect occurred throughout the experiment, with turtles making an average of 3.94 (±1.42 SE) fewer attempts at the end of the experiment (day 18) than on day 1. Bolder turtles were faster at crossing obstacles, but boldness had no influence on obstacle‐crossing success. Our results highlight the need for thoughtful selection of waterway, wetland, and riparian bordering infrastructure and the fatiguing impact of constant exposure to anthropogenic barriers for wildlife.

The role of mesocarnivores in wildlife communities tends to be overlooked, which has led to a large gap in natural history knowledge. In northeastern Argentina, two mesocarnivore foxes, Cerdocyon thous and Lycalopex gymnocercus, live in sympatry in noncompetitive coexistence. Their feeding habits have been studied in many occasions; however, the studies related to trophic variability in a wider spatial scale remain scarce. In this study, we aimed to analyze how the diet of these foxes varies in three protected areas in Argentina: the Mburucuyá National Park (MNP), the “San Nicolás Portal” (SN), and the Natural Reserve Rincón de Santa María (RSM). We collected fecal samples in each area, identified them using thin layer chromatography at species level, and classified the found feeding items to obtained two parameters: occurrence and relative frequency. Furthermore, we compared the diet of the two species in each site and between sites using chi‐square and estimated trophic niche breadth and overlap between the species. We found that both species consumed different food categories, with variable frequencies across study sites. We observed that in each area, the foxes differed in diet composition. However, we found no differences between the diet compositions of C. thous and L. gymnocercus, showing high niche overlap in each site. Here, we show the plasticity of both fox species in changing their diets even with small geographical variation. Both species can coexist even with a high diet overlap, possibly explained by their noncompetitive coexistence which may occur due to the current changes in the ecosystem interactions, or partitioning may exist but on a smaller niche level.