Finding a safe space: denning range dynamics of African wild dogs in Zimbabwe

African wild dogs utilise a den for ~10–12 weeks after birthing, during which home ranges are contracted and usually in areas away from roads and water sources, with low prey and predator abundances, high terrain ruggedness and vegetation cover. Our study in Savé Valley Conservancy (SVC) investigated which ecological and environmental factors determine the selection of denning areas and behaviours. Camera trap data collected from four den grids and three random den grids were analysed using binomial generalised linear and occupancy models. Denning wild dogs preferred areas with higher kudu and impala presence and areas closer to roads and water sources. Wild dogs may den in areas we perceive as riskier in an attempt to reduce energy expenditure when hunting. The detection of wild dogs strongly decreased with higher lion presence, while increasing with steeper slopes, higher vegetation cover and leopard presence. Given lion habitat preferences, SVC wild dogs could be using areas which reduce their exposure to lions, while solitary leopards do not necessarily pose a risk to wild dog packs. Our study highlights that the denning behaviours of wild dogs may be inconsistent both within and among populations, and that comprehensive research approaches be taken to understand their denning behaviours, assisting the development of appropriate management/conservation strategies

Total and tropospheric ozone changes: observations and numerical modelling

A survey has been made of total and tropospheric ozone dynamics in the context of its impacts on climate, human health and ecosystems. Observation data on total ozone content (TOZ) in the atmosphere and relevant numerical modelling results have been discussed as well as similar information for tropospheric ozone, whose formation and changes are being determined by quite different causes. A necessity has been emphasized to get more adequate global observational data on TOZ and tropospheric ozone (this is especially important in the latter case, because information on tropospheric ozone is far from being complete). Unsolved problems relevant to both total and tropospheric ozone have been briefly considered

Burst and persistent emission properties during the recent active episode of the anomalous x-ray pulsar 1E 1841-045

Copyright American Astronomical SocietyThe Swift/Burst Alert Telescope detected the first burst from 1E 1841-045 in 2010 May with intermittent burst activity recorded through at least 2011 July. Here we present Swift and Fermi/Gamma-ray Burst Monitor observations of this burst activity and search for correlated changes to the persistent X-ray emission of the source. The T-90 durations of the bursts range between 18 and 140 ms, comparable to other magnetar burst durations, while the energy released in each burst ranges between (0.8-25) x 10(38) erg, which is on the low side of soft gamma repeater bursts. We find that the bursting activity did not have a significant effect on the persistent flux level of the source. We argue that the mechanism leading to this sporadic burst activity in 1E 1841-045 might not involve large-scale restructuring (either crustal or magnetospheric) as seen in other magnetar sources.Peer reviewedFinal Accepted Versio

Predicting the Current and Future Potential Distributions of Lymphatic Filariasis in Africa Using Maximum Entropy Ecological Niche Modelling

Modelling the spatial distributions of human parasite species is crucial to understanding the environmental determinants of infection as well as for guiding the planning of control programmes. Here, we use ecological niche modelling to map the current potential distribution of the macroparasitic disease, lymphatic filariasis (LF), in Africa, and to estimate how future changes in climate and population could affect its spread and burden across the continent. We used 508 community-specific infection presence data collated from the published literature in conjunction with five predictive environmental/climatic and demographic variables, and a maximum entropy niche modelling method to construct the first ecological niche maps describing potential distribution and burden of LF in Africa. We also ran the best-fit model against climate projections made by the HADCM3 and CCCMA models for 2050 under A2a and B2a scenarios to simulate the likely distribution of LF under future climate and population changes. We predict a broad geographic distribution of LF in Africa extending from the west to the east across the middle region of the continent, with high probabilities of occurrence in the Western Africa compared to large areas of medium probability interspersed with smaller areas of high probability in Central and Eastern Africa and in Madagascar. We uncovered complex relationships between predictor ecological niche variables and the probability of LF occurrence. We show for the first time that predicted climate change and population growth will expand both the range and risk of LF infection (and ultimately disease) in an endemic region. We estimate that populations at risk to LF may range from 543 and 804 million currently, and that this could rise to between 1.65 to 1.86 billion in the future depending on the climate scenario used and thresholds applied to signify infection presence

Predicting the consequences of subsistence poaching on the population persistence of a non-target species of conservation concern

Illegal animal hunting, a contributor to biodiversity loss, occurs along a relative selectivity spectrum from indiscriminate to highly selective. Extensive research has evaluated the impacts of selective hunting on animal populations. In contrast, the ways in which indiscriminate hunting pressure can shape populations of non-target species has not yet received comparable attention. We used empirical field data collection and simulation modelling to predict the persistence of an African lion population (Panthera leo) subject to indiscriminate hunting pressure from non-target subsistence poaching via wire snares in Murchison Falls National Park, Uganda. Our simulation modelling predicted lion population extirpation following a 50 % rise of lethal poaching pressure above the observed levels. When lethal poaching pressure doubled, the lion population was extirpated in similar to 70 % of our simulations. We then simulated reductions in lethal poaching pressure to quantify the predicted population recovery of lions. We found that the lion population increased by 40 % with reductions in lethal poaching pressure of 50 %. When we removed lethal poaching pressure entirely, the lion population nearly doubled in just 18 years. Our results demonstrate that by reducing the density of wire snares in the study area by just 2.79/km(2), the lion population transitioned from being locally extirpated in 67 % of the simulations to reaching carrying capacity inside of two lion generations. We explore how vulnerable even non-target animals are to subsistence poaching and describe the types of applied practices that can be implemented to reduce wire snaring and effectively promote the population recovery of species of conservation concern

Anthropogenic edge effects and aging errors by hunters can affect the sustainability of lion trophy hunting

Abstract Many large predator populations are in decline globally with significant implications for ecosystem integrity and function. Understanding the drivers of their decline is required to adequately mitigate threats. Trophy hunting is often cited as a tool to conserve large mammal populations but may also have negative impacts if not well managed. Here we use a spatially implicit, individual based model to investigate the threats posed to African lion populations by poorly managed trophy hunting and additive anthropogenic mortality such as poaching and retaliatory killing. We confirm the results of previous studies that show that lion trophy hunting can be sustainable if only older male lions are hunted, but demonstrate that hunting becomes unsustainable when populations are exposed to additional anthropogenic mortality, as is the case for most free ranging populations. We show that edge effects can be a critical determinant of population viability and populations that encompass well protected source areas are more robust than those without. Finally, errors in aging of hunted lions by professional trophy hunters may undermine the sustainability of the age-based quota setting strategies that are now widely used to manage lion trophy hunting. The effect of aging errors was most detrimental to population persistence in the ≥ 6 and ≥ 7 year-old age thresholds that are frequently used to define suitably aged lions for hunting. Resource managers should limit offtakes to older demographics and additionally take a precautionary approach when setting hunting quotas for large carnivore populations that are affected by other sources of anthropogenic mortality, such as bush-meat poaching, retaliatory killing and problem animal control

Listening to lions : animal-borne acoustic sensors improve bio-logger calibration and behaviour classification performance

Efforts to better understand patterns of animal behaviour have often been restricted by several environmental, human and experimental limitations associated with the collection of animal behavioural data. The introduction of new bio-logging technology has offered an alternative means of recording animal behaviour continuously and is being used in an increasing number of studies. Accurately calibrating these bio-loggers, however, still remains a challenge in many cases. Using lions as an example species, we test how audio recordings from animal-borne acoustic sensors can improve calibration and behaviour classification. Through a collaborative effort between computer scientists, engineers, and zoologists, custom designed acoustic bio-loggers were fitted to eight lions and recorded audio simultaneously with accelerometer and magnetometer data. Audio recordings were then used as the source of ground truth to train random forest classification models as well as to provide additional predictor variables for behaviour classification. We demonstrated near-perfect classification performance for five lion behaviour classes when all component variables were combined, with an average per- class precision of 98.5%. Using accelerometer features only, the audio-trained classifier predicted behaviours with an average per-class precision of 94.3%. On-animal audio recordings are therefore able to provide a valuable source of ground-truth for calibrating bio-loggers while also offering additional predictive features for increasing the accuracy of behaviour classification. This technological innovation has wide ranging application and provides a useful tool for behavioural ecologists wishing to collect fine scale behavioural data for animal research and conservation.Audio 1 | Eating.Audio 2 | Drinking.Audio 3 | Fast.Audio 4 | Slow.Audio 5 | Stationary.The John Fell Fund and the Beit Trust.http://www.frontiersin.org/Ecology_and_Evolutionam2019Mammal Research InstituteZoology and Entomolog

The hunting modes of human predation and potential nonconsumptive effects on animal populations

When seeking prey, predators adaptively deploy strategies coarsely divided into sit-and-wait, sit-and-pursue, or active hunting modes. Though the hunting modes of many predators have been extensively studied, the implications of the hunting modes of human (Homo sapiens) predation are not yet fully understood. We conducted an extensive literature review to document human hunting modes and explore the ways in which these modes may shape animal populations via nonconsumptive effects (NCEs) of human predation. Among 167 studies published between 1972 and 2020, we found that humans used 27 hunting tools among 19 different hunting techniques when pursuing terrestrial prey. Most accounts described humans as using the active hunting mode (58%; n = 140 of 241), followed by the sit-and-wait hunting mode (41%; n = 99 of 241), and finally the sit-and-pursue hunting mode (2%; n = 4 of 241). While non-human predators tend to be evolutionarily adapted to the use of just one hunting mode, humans showed profound plasticity by deploying all three hunting modes in pursuit of prey species from 34 taxonomic orders spanning six orders of magnitude in body size (from 27 g to 4,400 kg). Considerable evidence has documented the vast number of ways in which humans directly impact the functioning of the natural world. Our research complements that work by demonstrating the indirect pathways by which humans may affect animal populations and the landscapes over which these interactions occur, via NCEs deriving from the hunting modes of human predation, with important implications for animal conservation

Vocal discrimination of African lions and its potential for collar-free tracking

International audiencePrevious research has shown that African lions (Panthera leo) have the ability to discriminate between conspecific vocalisations, but little is known about how individual identity is conveyed in the spectral structure of roars. Using acoustic – accelerometer biologgers that allow vocalisations to be reliably associated with individual identity, we test for vocal individuality in the fundamental frequency (f0) of roars from 5 male lions, firstly by comparing simple f0 summary features and secondly by modelling the temporal pattern of the f0 contour. We then assess the application of this method for discriminating between individuals using passive acoustic monitoring. Results indicate that f0 summary features only allow for vocal discrimination with 70.7% accuracy. By comparison, vocal discrimination can be achieved with an accuracy of 91.5% based on individual differences in the temporal pattern of the f0 sequence. We further demonstrate that passively recorded lion roars can be localised and differentiated with similar accuracy. The existence of individually unique f0 contours in lion roars and their relatively lower attenuation indicates a likely mechanism enabling individual lions to identify conspecifics over long distances. These differences can be exploited by researchers to track individuals across the landscape and thereby supplement conventional lion monitoring approaches

Vocal discrimination of African lions and its potential for collar-free tracking

Previous research has shown that African lions (Panthera leo) have the ability to discriminate between conspecific vocalisations, but little is known about how individual identity is conveyed in the spectral structure of roars. Using acoustic – accelerometer biologgers that allow vocalisations to be reliably associated with individual identity, we test for vocal individuality in the fundamental frequency (f0) of roars from 5 male lions, firstly by comparing simple f0 summary features and secondly by modelling the temporal pattern of the f0 contour. We then assess the application of this method for discriminating between individuals using passive acoustic monitoring. Results indicate that f0 summary features only allow for vocal discrimination with 70.7% accuracy. By comparison, vocal discrimination can be achieved with an accuracy of 91.5% based on individual differences in the temporal pattern of the f0 sequence. We further demonstrate that passively recorded lion roars can be localised and differentiated with similar accuracy. The existence of individually unique f0 contours in lion roars and their relatively lower attenuation indicates a likely mechanism enabling individual lions to identify conspecifics over long distances. These differences can be exploited by researchers to track individuals across the landscape and thereby supplement conventional lion monitoring approaches.The John Fell Fund, University of Oxford and the Beit Trust.http://www.tandfonline.comtoc/tbio202021-10-02hj2021Mammal Research InstituteZoology and Entomolog