Samuel G. Penny

Drones are becoming increasingly valuable tools in wildlife studies due to their ability to access remote areas and offer high-resolution information with minimal human interference. Their application is, however, causing concern regarding wildlife disturbance. This review synthesizes the existing literature on how animals within terrestrial, aerial, and aquatic environments are impacted by drone disturbance in relation to operational variables, sensory stimulation, species-specific sensitivity, and physiological and behavioral responses. We found that drone altitude, speed, approach distance, and noise levels significantly influence wildlife responses, with some species exhibiting increased vigilance, flight responses, or physiological stress. Environmental context and visual cues are also involved in species detection of drones and disturbance thresholds. Although the short-term response to behavior change has been well documented, long-term consequences of repeated drone exposure remain poorly known. This paper identifies the necessity for continued research into drone–wildlife interactions, with an emphasis on the requirement to minimize disturbance by means of improved flight parameters and technology.

Drones are becoming increasingly valuable tools in wildlife studies due to their ability to 1 access remote areas and offer high-resolution information with minimal human interference. Their 2 application is, however, causing concern regarding wildlife disturbance. This review synthesizes the 3 existing literature on how animals within terrestrial, aerial, and aquatic environments are impacted by 4 drone disturbance in relation to operational variables, sensory stimulation, species-specific sensitivity, 5 and physiological and behavioral responses. We found that drone altitude, speed, approach distance, 6 and noise levels significantly influence wildlife responses, with some species exhibiting increased 7 vigilance, flight responses, or physiological stress. Environmental context and visual cues are also 8 involved in species detection of drones and disturbance thresholds. Although the short-term response 9 to behaviour change has been well documented, long-term consequences of repeated drone exposure 10 remain poorly known. This paper identifies the necessity for continued research into drone-wildlife 11 interactions, with an emphasis on the requirement to minimize disturbance by means of improved 12 flight parameters and technology.

The African large predator guild is one of the last intact large predator guilds globally, and interactions between its members influence ecosystem functioning. We conducted camera‐trapping in the Maasai Mara Ecosystem (MME) to estimate leopard (Panthera pardus) population density and investigate whether lion (Panthera leo) and hyaena (Crocuta crocuta) impact leopard presence, while accounting for potential prey presence and habitat. In 2019, we deployed cameras at 34 stations in the Mara Triangle within the MME for 63 nights. We estimated leopard density using a closed population spatially explicit capture–recapture (SECR) framework and examined potential predictors of leopard presence using generalised linear mixed modelling. We recorded 725 leopard images and estimated population density at 1.90 ± 0.56 individuals 100 km²⁻¹, relatively low compared to other areas and only slightly higher than previous MME estimates of cheetah, an ecologically subordinate competitor. The best model predicting leopard presence contained hyaena occurrence and showed a positive association, indicating ‘co‐occurrence’. Hyaenas commonly kleptoparasitise leopard kills in MME; that is hyaenas may follow leopards for this reason. Although our preliminary results indicate that hyaena populations may limit leopard populations in the MME, further work is required to explicitly test hypotheses relating to hyaena–leopard interactions.

Representing one of the last populations of an IUCN Critically Endangered subspecies, estimates suggest the Kordofan giraffe of Cameroon's Bénoué Complex number fewer than 300 individuals, threatened by poaching and habitat degradation. This study investigated the viability of Bénoué National Park's Kordofan giraffe and efficacy of available interventions through a population viability analysis using VORTEX. The relative impacts of anti‐poaching activity, population supplementation, habitat protection and vaccination were explored, alongside a sensitivity analysis investigating parameter uncertainty. The baseline model projects a 78.6% probability of extinction (PE) within 100 years. Poaching of just two individuals every 5 years results in a 98.1% PE, highlighting anti‐poaching activity as a vital intervention. Movement of a female‐biased group into the park proved effective, with supplementation of 24 females reducing the PE by over 35%, sustaining a raised population size above the baseline for over 60 years on average. Annual carrying capacity reduction of 2% year⁻¹ for 20 years resulted in a 97.8% PE. Conversely, habitat restoration had little consequence unless combined with further interventions. These findings underscore the magnitude of the threat facing Bénoué National Park's Kordofan giraffe. Conservation management should prioritise strengthening existing anti‐poaching activity in conjunction with protecting wildlife corridors to aid dispersal.

This large, international dataset contains survey responses from N = 12,570 students from 100 universities in 35 countries, collected in 21 languages. We measured anxieties (statistics, mathematics, test, trait, social interaction, performance, creativity, intolerance of uncertainty, and fear of negative evaluation), self-efficacy, persistence, and the cognitive reflection test, and collected demographics, previous mathematics grades, self-reported and official statistics grades, and statistics module details. Data reuse potential is broad, including testing links between anxieties and statistics/mathematics education factors, and examining instruments’ psychometric properties across different languages and contexts. Data and metadata are stored on the Open Science Framework website [https://osf.io/mhg94/].

In many social species physical attributes correlate with dominance rankings and influence the outcomes of dyadic interactions. We investigated the processes that affect white rhinoceros’ social behaviour in response to a reduction in horn size asymmetries within a group of subadult individuals. We monitored agonistic social interactions and the orderliness of social rankings between six free ranging rhinoceroses before and after they underwent a second dehorning procedure. We used a modified version of Landau’s h’ to measure linearity, a score of steepness to measure power asymmetry, and a measure of triangle transitivity to assess relationships in the presence of null dyads. Agonistic social interactions were significantly greater after the monitored dehorning procedure. Hierarchies possessed significant steepness and transitivity prior to the procedure, but not after. Linearity was non-significant and rank order did not correspond with changes in horn size or age. Our results provide the first evidence of a dominance hierarchy among free-ranging white rhinoceroses outside of reproductive competition, but indicate that physical attributes alone do not explain social rankings. Rhinoceroses transitioned to a more egalitarian dominance structure than a despotic one after the procedure, but dominance ranks were only weakly differentiated within the group. Although a reduction in horn asymmetries may increase agonistic behaviours via psychosocial or behavioural changes, drier climatic conditions cannot be ruled out as the causative factor and because the subadult group stayed together, rather than dispersing, any increased fitness costs are likely to be minimal and outweighed by the benefits of group membership.

Does dehorning lead to a change in inter-calf intervals in free-ranging white rhinoceros?

White-handed gibbons produce loud and acoustically complex songs when interacting with their neighbours or when encountering predators. In both contexts, songs are assembled from a small number of units although their composition differs in context-specific ways. Here, we investigated whether wild gibbons could infer the ‘meaning’ when hearing exemplars recorded in both contexts (i.e. ‘duet songs’ vs. ‘predator songs’). We carried out a playback experiment by which we simulated the presence of a neighbouring group producing either its duet or a predator song in order to compare subjects’ vocal and locomotor responses. When hearing a recording of a duet song, subjects reliably responded with their own duet song, which sometimes elicited further duet songs in adjacent groups. When hearing a recording of a predator song, however, subjects typically remained silent, apart from one of six groups which replied with its own predator song. Moreover, in two of six trials, playbacks of predator songs elicited predator song replies in non-adjacent groups. Finally, all groups showed strong anti-predator behaviour to predator songs but never to duet songs. We concluded that white-handed gibbons discriminated between the two song types and were able to infer meaning from them. We discuss the implications of these findings in light of the current debate on the evolutionary origins of syntax.

A new species of the miniaturised microhylid frog genus Stumpffia, from north-western Madagascar, is described. Stumpffia froschaueri sp. nov. differs from all other described Stumpffia species in colouration and morphology and is genetically divergent (>= 7% uncorrected p-distance to all other nominal species of the genus) in a fragment of the mitochondrial 16S rRNA gene and in a segment of the nuclear Rag-1 gene. The new species is reliably known only from a few specimens collected in the Sahamalaza (and surroundings) region. Its known distribution is limited to three forest patches severely threatened by fire, drought and high levels of forest clearance, thus suggesting a classification of "Critically Endangered" according to IUCN Red List criteria.

The white rhinoceros (Ceratotherium simum) is experiencing unsustainable poaching losses fuelled by a demand for horn. Increasingly, private and state reserves are dehorning their rhinoceros populations in an attempt to reduce poaching pressure. Rhinoceroses use their horns in social interactions as well as during resource access and so its partial removal as part of reserve management practices may adversely influence these behaviours. Physiological stress can correlate with animal welfare, reproductive state and health and thus acts as a useful indicator of these parameters. To establish whether dehorning causes a physiological stress response, glucocorticoid and gonadal steroid profiles of free-ranging white rhinoceroses were determined through the collection and analysis of faecal steroid metabolites before and after dehorning. Faecal corticoid profiles were not influenced by the number of occasions a rhinoceros had been dehorned or by the number of days that had elapsed since dehorning. Furthermore, there was no apparent suppression in the concentrations of testosterone or progesterone metabolites in males and females, respectively, after exposure to multiple dehorning procedures. These findings should increase wildlife managers’ confidence that dehorning does not negatively impact white rhinoceros physiology as measured hormonally.