School for Field Studies

The elasmobranch fauna was studied in the Khor Faridah region of Abu Dhabi, which is a mangrove-dominated inshore habitat historically reported to host a diversity of elasmobranch species. A stereo-baited remote underwater video system (Stereo-BRUVS) survey was conducted from September 2021 to August 2022 to assess the species diversity and relative abundance of elasmobranch fishes. A total of 12 elasmobranch taxa were encountered during the study, consisting of five rays (Myliobatiformes), four sharks (Selachii), two wedgefish and one guitarfish (Rhinopristiformes). The area was dominated by honeycomb-patterned rays in the genus Himantura and the Critically Endangered Arabic whipray Maculabatis arabica. Since Himantura uarnak and H. leoparda could not be reliably distinguished from footage, all sex- and size-based results are reported for a combined Himantura species complex and should be interpreted cautiously. Furthermore, the broad size range of individuals found in the area highlights its importance to all life stages of these taxa. This underlines the need for a conservation strategy to avoid detrimental changes to the elasmobranch fauna due to ongoing coastal development.

ABSTRACTWildlife tourism can support conservation but also imposes stress on wildlife, particularly cognitively complex and social species like Asian elephants (Elephas maximus), highlighting the need for science‐based management regulations. We assessed the behavioral responses of wild Asian elephants in Kuiburi National Park, Thailand, against varying levels of tourism pressure using scan and focal sampling over three years, including during park closures. We hypothesized that tourism pressure influences elephant behavioral responses, with the strength and nature of responses varying according to disturbance intensity, demographics, and environmental variables. Tourism pressure was measured at two scales: sighting tourism pressure (STP; number of people, vehicles, distance, and noise at each elephant sighting) and Daily Tourism Pressure (DTP; total daily tourists). Elevated numbers of vehicles, people, noise, and close distances significantly increased rates of stress‐related, vigilance, and passive aggressive behaviors while reducing affiliative behavior and prompting retreat. The most consistently selected tourism‐related predictors of behavior were number of vehicles, number of people, proximity to humans, and noise level, with affiliative behavior emerging as the most sensitive indicator of disturbance. Behavioral thresholds were identified for “ideal” and “acceptable” tourism conditions: > 100 m/125 m viewing distance, < 4/< 8 vehicles, < 10/< 21 people, and noise < 32/< 42 dB, beyond which negative behavioral responses increased significantly. Following park re‐openings, elephant detections declined, especially for cow‐calf groups, indicating increased avoidance and vulnerability to tourism of socially cohesive groups. These results support evidence‐based regulations for wildlife tourism, including the use of thresholds for management such as buffer zones, quiet viewing protocols, daily and sighting vehicle and visitor caps, guide training, and adaptive seasonal closures. Integrating empirically derived behavioral thresholds into protected area and national policies provides a scalable and transferable model to reduce disturbance, improve animal welfare, and promote ethical and sustainable elephant tourism in Thailand and beyond.

Jamie Duncombe explains the protocols around the testing and validation of autoclaves, whilst outlining key points to consider when purchasing an autoclave. Objectives To teach readers about the different types of dental autoclaves. To give readers an understanding of the protocols around the testing and validation of autoclaves. To give readers an understanding of the factors to be considered when purchasing an autoclave.

ABSTRACTThe African lion (Panthera leo Linnaeus, 1758) has evolved complex associations in which individual survival is an interplay of cooperation among pride members. Although feeding behaviors of African lions are widely known, our understanding of how age and sex classes affect per capita intake of other individual members in a pride remains unclear. This study used long‐term population monitoring data collected from 2004 to 2023 to assess how prey size and feeding group composition affect different age/sex class interactions and per capita food intake of African lion cubs, subadults, adult males, and adult females. The results indicate that African lion feeding group composition and interaction patterns at carcasses were affected by prey size. Cub per capita food intake was reduced by increased numbers of cubs and subadults. For subadults, the per capita intake was reduced as the number of cubs, subadults, and adult females increased. However, subadults increased their per capita intake rates when feeding together with both cubs and adult females. Adult females also showed competitive interactions when feeding at carcasses with cubs, subadults, and fellow adult females. Nevertheless, the adult female per capita intake was increased when more females fed with cubs or subadults and when feeding in combination with cubs and adult males. For adult male lions, only increased numbers of adult females led to a reduced per capita intake at carcasses, reflecting competition. These varied effects on per capita food intake suggest how age and sex‐based composition of feeding groups play a role in the foraging success of African lions and how food availability may influence the demographic composition of prides.

The chytrid fungus Batrachochytrium dendrobatidis (Bd) is implicated in global declines and extinctions of amphibian species. Although Bd is found on all continents where amphibians persist, disease dynamics and prevalence remain poorly quantified and understood in certain regions of the world, such as West Africa. West Africa is characterized as a “safe haven” for amphibians despite niche models indicating that there is suitable habitat for Bd in this region. Therefore, a major knowledge gap remains regarding the threats that Bd poses to West African amphibians. We screened 3093 fluid-preserved amphibian specimens to determine the historical prevalence of Bd in West Africa. We detected five Bd-positive samples originating from Ghana and Benin, with the earliest positive occurrence dating back to 1969, suggesting that Bd has been present in West Africa for at least 54 yr. We obtained sequence data for two of these samples and both correspond to the BdGPL2 clade. West Africa hosts amphibian assemblages that are distinct from any other African region; thus continued Bd surveys are crucial for defining the extent of Bd across Africa and understanding whether this pathogen poses a threat to the unique amphibian diversity of this region.

Bipolar disorder is a neuropsychiatric disease affecting 1-4% of the worldwide population; characterized by spontaneous depressive and manic episodes, very little is known about the pathology of bipolar disorder, and there is no known cure. Theorized pathologies of bipolar disorder include genetic and environmental factors, the dopamine hypothesis, and the role of gut microbiota. This paper reviews several pieces of scientific literature pertaining to these theories, integrating optogenetics as a research tool to more accurately examine and manipulate relevant cellular activity. The reviewed literature draws clear connections from the HPA axis, gut microbiota, circadian rhythms, and dopaminergic expression to the pathology and manifestation of bipolar disorder. However, despite this, there is simply not enough information about the disease itself for researchers to come to a sound conclusion. The disparity is mentioned at least once in each piece of literature and is attributed to both the ambiguity of the disease, and the variability in symptoms between patients. Not only does this affect the current theories surrounding bipolar disorder, but also makes studying the disease incredibly difficult, as without a pathology, ideal animal models are nearly impossible to identify. Literature rooted in the use of optogenetics present results which express increased specificity in both data and conclusions, cementing its potential in future studies concerning bipolar disorder. From this, this paper proposes a new behavioral experimental design in mouse models, integrating optogenetics with the most prevalent theories of the pathology of bipolar disorder.

Abstract Self-incompatibility (SI) is a genetic mechanism to prevent self-fertilization and thereby promote outcrossing in hermaphroditic plant species through discrimination of self and non-self pollen by pistils. In many SI systems, recognition between pollen and pistils is controlled by a single multiallelic locus (calledS-locus), in which numbers of alleles (calledS-alleles) are segregating. Because of the extreme level of polymorphism of theS-locus, identifications ofS-alleles have been a major issue in many SI studies for decades. Here we report an RNA-seq-based method to explore allelic diversity of theS-locus by employing the long-read sequencing technology of the Oxford Nanopore MinION, and applied it for the gametophytic SI system ofPetunia(Solanaceae), in which the female determinant is a secreted ribonuclease called S-RNase that inhibits the elongation of self-pollen tubes by degrading RNA. We developed a method to identifyS-alleles by the search ofS-RNasesequences, using the previously reported sequences as queries, and found in total 62 types ofS-RNaseincluding 45 novel types. We validated this method through Sanger sequencing and crossing experiments, confirming the sequencing accuracy and SI phenotypes corresponding to genotypes. Then, using the obtained sequence data together with PCR-based genotyping in a larger sample set of 187 plants, we investigated the diversity, frequency, and the level of shared polymorphism ofS-alleles across populations and species. The method as well as the dataset obtained inPetuniawill be an important basis for further studying the evolution of S-RNase-based gametophytic SI systems in natural populations.Significance statementFlowering plants have evolved molecular mechanisms called self-incompatibility (SI) for discriminating self and non-self pollen at pistils to prevent self-fertilization, which is often deleterious due to inbreeding depression. The specificity of SI is usually determined by numbers of highly divergent alleles (calledS-alleles) segregating at a single locus, and identifications ofS-alleles have been a major issue in many SI systems. Here we report a new method to identifyS-alleles by employing a long-read sequencing technology and applied it for the gametophytic SI system ofPetunia, identifying 62 types ofS-alleles including 45 novel types. The method as well as the dataset obtained in this study will be an important basis for the research of SI evolution.

Specialisation in food resource use is a crucial process that fosters species coexistence in plant–animal networks, contributing to the maintenance of biodiversity, ecological complexity, and community stability. Notably, although there is a vast literature on ecological specialisation in pollination systems, the evolutionary similarity among the plant species visited by particular pollinators has been largely ignored. Here, we apply a robust phylogenetic approach to analyse whether the evolutionary relatedness of plant species is a significant factor in mediating pollinator visits and how it relates to the morphology of interacting species. We quantified ecological and clade specialisation of hummingbird and insect species in three mutualistic networks from the Costa Rican highlands and associated these metrics with species traits. We found that hummingbirds were overall ecologically more specialised than insects (i.e. visited a less diverse set of plant species). However, when evaluating the phylogenetic relatedness among the visited plant species, all hummingbird species and most insects had overdispersed diets, which indicates they visited phylogenetically distant plant species in the community. Moreover, a great proportion of these clade generalists visited plant species with a great variation in corolla length, showing a lack of preference for this morphological trait. Altogether, our results demonstrate that by incorporating plant phylogeny to network analysis, pollinator species were generalists and that corolla length weakly influences plant–pollinator interactions in the three studied networks. A phylogenetic perspective should occupy a central role in the study of specialisation since it contributes to understanding the interplay between ecological and evolutionary processes in mutualistic networks. Future research should focus on evaluating whether the phylogenetic structure of animal diets mediates patterns of interactions in different types of mutualisms and environmental contexts, linking these patterns to other floral traits. This knowledge may be valuable for deepening our comprehension of the underlying mechanisms shaping ecological networks.