Abstract Artificial nests allow us to analyze the use of space by animals without influencing their behavior. We characterized the shelters built by marsupials and the plant resources used for their construction. We also evaluated the use of vertical space through artificial nests arranged at 1.5 m and 3 m height in an area of Atlantic Forest in Sergipe, Brazil, between April 2022 and May 2023. A total of 124 shelters with preferably dry leaves were recorded. Only 18.4% of artificial nests were occupied, one of them with two sub-adult individuals of Marmosa murina. The animals used leaves from the Rubiaceae (all shelters), Melastomataceae, Phyllanthaceae and Erythroxylaceae families. There was no difference between the types of shelters built by the species. There was no relationship between the body size of the animal and the built-up area of the shelter. Marmosa demerarae was more frequent at 3.0 m while M. murina did not differ in the use of strata. The frequency of records between the strata differed between these species, despite the high overlap observed. Both species used artificial nests in both strata of vegetation and built their shelters with the leaves available on the ground. The regular availability of this resource has made it possible to occupy the artificial nests regardless of seasonality. The shelter is built gradually, resulting in different configurations. However, the scarcity of information on the architecture and composition of the shelters built by marsupials makes it difficult to understand the factors that influence the use of these sites by the species.

Abstract The behavioral rhythm and time distribution of the Chinese monal (Lophophorus lhuysii) in captivity was different from those in the wild, and this may affect its reproductive rate and survival status. In order to understand the behavior characteristics of captive Chinese monals, between August 2016 and August 2017 an instantaneous scanning method was employed to investigate the daily behavioral rhythm of captive Chinese monals in Fengtongzhai National Nature Reserve, Sichuan Province, China. The results indicated the following: the daily behavioral rhythm of Chinese monals demonstrated the absence of a distinct feeding peak during the spring breeding season. In summer, autumn, and winter, foraging and wandering behaviors exhibited peaks in both the morning and evening, while resting behavior and foraging or wandering behavior displayed distinct peaks. Preening behavior was observed across all seasons, with a peak occurring around noon. Differences in diurnal behavioral rhythms between males and females were noted across all seasons. The time distribution of daily behavior demonstrated notable seasonal regularity and periodicity, and also showed differences between males and females. In spring, no significant differences were found between males and females in feeding, resting, preening, and sand-bathing behavior (all ). During summer, the sand-bathing behavior of males was significantly lower than that of females (all ). In autumn, males exhibited a significantly higher frequency of forging behavior () and a significantly lower frequency of resting behavior compared to females (). Additionally, wandering behavior in males was significantly lower than in females (). In winter, the sand-bathing behavior of males was significantly lower than that of females (). This study is not only of great significance for the conservation and artificial breeding of this species, but also has practical application value for understanding its ecological habits and improving the level of feeding and management.

Abstract Freshwater decapods, such as the crabs in the family Trichodactylidae, are key components of benthic food webs, but research on their trophic ecology is limited. This study aimed to investigate variations in the natural diet of the freshwater crab Dilocarcinus pagei in the Araguari River, Brazil. We analyzed demographic groups and seasonal differences in stomach fullness, volume, and frequency of occurrence of various dietary items. Our results revealed that stomach fullness varied among demographic groups, with adult females showing lower levels and juvenile females showing higher levels. Analysis of stomach contents identified 12 types of items, including unidentified animals, detritus, sand, plastic filaments, and molluscs. Juvenile females showed a higher consumption of plant tissue, while only adult males and juveniles showed a consumption of molluscs. Plant tissue and detritus (digested material) were the most frequent items. These findings reveal the feeding habits of D. pagei in the sampling area, highlighting the influence of demographic groups and seasonal variations on their diet, including the consumption of plant tissue, predation on molluscs, and ingestion of microplastics.

Abstract Earthworms have a complex digestive system consisting of the mouth, pharynx, esophagus, crop, gizzard, and intestine which work together to pass the soil out. The gut soil and associated microbial load in earthworms’ gut hinder the outcome of many experiments like in-vitro regeneration, histology, immunohistochemistry, molecular expression and toxicological studies. Currently, the available gut cleaning techniques are time-consuming and costly. The tissue paper method takes 4-7 days; the agar-agar method takes around 3-5 days to clean the gut. Therefore, refined techniques are needed to reduce the gut cleaning process in a cost-effective and at the same time in a minimum number of days. Bisacodyl is a medication used to treat constipation and it acts as a laxative drug that increases peristatic movement of the gut. It can also be used to cleanse the intestines before a bowel examination or surgery. The present study aims to enhance the gut-cleaning process in earthworm, Eudrilus eugeniae, using the drug bisacodyl. Briefly, the earthworm is exposed to different concentrations (1 mg, 2 mg, 4 mg, 6 mg, 8 mg and 10 mg) of bisacodyl and analyzed for its excretion rate. We observed that 4 mg is more efficient and aids in cleaning the earthworm’s gut within two days. A lower bisacodyl concentration is inefficient in cleaning the gut in a shorter duration while at higher bisacodyl concentrations, worm experienced autotomy. Since the drug was active for only 45 mins, the worm became normal one hour after withdrawal from the experiment. Other than E. eugeniae, for Perionyx excavatus we observed 4 mg bisacodyl drug is efficient and aids in cleaning its gut within two days. Overall, the designed protocol is efficient for gut cleaning in a shorter duration in a cost-effective manner.

Abstract The house-farmed edible-nest swiftlet (Aerodramus sp.) is monogamous, produces nests from hardened saliva, and uses echolocation to navigate in the darkness. Most previous studies have focused on swiftlet nest building and incubation behaviour, but nestling provisioning behaviour, crucial for the survival of offspring during the breeding season, remains unclear. This study examined the nestling provisioning behaviour of house-farmed swiftlets at a swiftlet house farm in central Peninsular Malaysia. Complete focal video footage of the provisioning phase of swiftlets was analysed in detail. The overall feeding period decreased as the chick grew older. The parents alternately visited their nest 6-14 times a day from dawn to dusk to feed the nestling. The peak of this activity was from 07:00 to 08:00 and between 19:00 and 20:00. Nestling provisioning behaviour differed between pairs. The egg-laying interval of parents with two chicks was longer and affected the development of the second chick since the first chick more successfully competed for food and grew larger in size. Most second chicks with a smaller body size did not survive, because of being either purposely or unintentionally eliminated by the parents or sibling. The smaller-sized second chicks that survived took a longer time to fledge than the first chick; therefore, parents had to increase their foraging effort to ensure the survival of their chick until fledging. These behaviours may be influenced by physiological factors, such as age, experience, individual fitness, and abiotic factors, such as weather and food resources; therefore, different parental strategies may be established during the nestling provisioning phase.

Abstract The cooperative breeding system of birds is an ideal model for studying and exploring social evolution in animals. However, a basic question, i.e., how many cooperative-breeding bird species exist in the world, remains controversial due to the lack of accumulated knowledge of the natural history of many birds, which prevents a generalized understanding of the evolution of cooperative breeding in birds and challenges the accuracy of results in many comparative studies. In this paper, we provide the first evidence of cooperative breeding in red-billed blue magpies (Urocissa erythrorhyncha). Moreover, we document and discuss potential relationships between cooperative breeding and nest predation, brood parasitism and breeding performance in U. erythrorhyncha. These findings about cooperative breeding in red-billed blue magpie will lay a foundation for further research on this species’ sociality and provide useful insights into the evolution of cooperative breeding and other social systems in birds.

Abstract Knowledge of diets is important for understanding species ecology and the mechanism of coexistence of multiple closely related species. Two rhinolophid bats, the greater Japanese horseshoe bat (Rhinolophus nippon) and the little Japanese horseshoe bat (Rhinolophus cornutus), occur in Japan, but little is known about their diets and interspecific interactions regarding food resources. In this study, we examined the fecal contents of these two species in the Southern Japanese Alps by microscopic analysis over multiple seasons. R. cornutus, which have more skillful flight, consumed nonvolant insects (caterpillars and spiders), whereas R. nippon did not; this indicates that R. cornutus can glean prey better than R. nippon. The larger-bodied R. nippon more frequently consumed hard-bodied beetles, whereas the smaller-bodied R. cornutus more frequently consumed soft-bodied dipterans and neuropterans. Body size differences influenced flight ability and bite force, which resulted in food resource partitioning and enabled multispecies coexistence of these closely related bats. A R. nippon nursery colony consumed a wider variety of insects, such as beetles, moths, and dipterans, during the pregnancy and lactation periods; however, after lactation, they showed a beetle-dependent diet, and before hibernation they again consumed various food resources. A R. cornutus non-nursery colony frequently consumed dipterans and moths in spring; dipterans, moths, and neuropterans in autumn; and moths and neuropterans in winter. These seasonal changes in diet seemed to be related to food supply or reproductive status.

Abstract Boldness is closely related to fish species’ adaptative strategies and invasiveness and has become the focus of fish personality research. However, due to the lack of studies on behavioral stages, the ecological functions of certain behaviors remain unclear. To better understand the link between boldness and invasiveness in stone moroko (Pseudorasbora parva), an invasive Asian fish species, we exposed the fish to an open-field environment for 60 min and assessed their behavioral patterns, profiles, and stages. The results show that the boldness behavior of stone moroko was characterized by high activity, low average velocity, and diverse swimming postures. Five behavioral stages with significant differences were revealed: outbreak, inhibition, slow swimming, exploration, and adaptation. These observations suggest that stone moroko can quickly habituate to new environments. In addition, stone moroko spent more energy on exploring the living area and less on environmental risk assessment, as revealed by an analysis of their energy trade-off strategy. The behavioral strategies of stone moroko may explain their extremely high environmental adaptability and ability to invade multiple environments.

Abstract Understanding climatic variables to determine the ecological niche is crucial to explaining species distributions and revealing how sister species coexist within a geographic area. Here, we used ecological niche modeling to determine the ecological niche patterns of two toad species in Türkiye: Bufo bufo and Bufo verrucosissimus. Thus, we tested the ecological niche divergence and similarity between these species. In our results, the potential distribution of B. verrucosissimus showed high suitability throughout all Caucasus hotspots, and this suitability has been found even along the middle and western coast of Türkiye, but suitability was found to be very weak in the southern part of Türkiye. For B. bufo, the distribution pattern indicated high suitability along the Black Sea and Mediterranean coasts of Türkiye, but this suitability was low throughout Caucasus hotspots. Furthermore, we found that among B. bufo and B. verrucosissimus, the niches are not identical, but this situation is different in the background test. Therefore, we suggested that although there is niche conservatism between the two sister species, this pattern is caused by geographic barriers, not climatic parameters.

Abstract Frugivory and seed dispersal are fundamental ecological processes for the maintenance and conservation of tropical forest areas and ecosystem resilience. Here we investigated factors that could affect the relationship between frugivorous birds and fruit consumption, such as body mass, niche relationships, and species taxonomic groups, and the effects of such factors on the robustness of mutualistic bird-plant interaction networks. More specifically, we used Horn-Morisita niche overlap, the body mass coefficient of variation, and the variation in taxonomic distinctness index (varTD) as explanatory variables, and we applied multiple linear regression to test the that increased robustness in bird-plant frugivory networks occurs where birds have larger trophic niche overlaps and lower body mass variations and decreased robustness where they are more taxonomically diverse, in response to less functional redundancy. The analysis was based on literature data and fecal samples of birds collected after mist netting procedures. Bird body mass and niche overlap did not explain the variation in robustness in seed dispersal networks. However, different from expected, the results showed an effect of variations in taxonomic distinctness, suggesting that the larger the taxonomic distinctness of birds in a frugivore assemblage, the larger the robustness of the networks. Some hypotheses were suggested to explain this effect. Regardless of the factors that lead varTD to favor the robustness of mutualistic bird-plant networks, the results demonstrated that conserving diversity above the species level, and not just species limited to a few taxonomic groups, can be an important strategy for ecosystem conservation over time.