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Copyright of African Journal of Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Large herbivores in seasonal environments often experience mass variation due to temporal changes in the availability of critical resources like water and forage, as well as due to breeding events. Yet the documentation of mass variation in mammals of highly seasonal savanna habitats, which host the highest densities of grazing ungulates globally, has rarely been explored. Here, we showcase a method to evaluate seasonal mass variation in bovids. Our method used mineral‐baited scales and camera traps to enable us to track the body mass of three species through a period of wet and dry seasons in a South African savanna ecosystem. To illustrate one potential application of the method, we related body mass data to time, weather and resource availability. This showed that individuals altered their body masses markedly between seasons with, for example, female Kudu (Tragelaphus strepsiceros) gaining, on average, >21 kg over the 15‐week wet‐season period in 1 year. These changes were positively related to factors such as vegetation productivity (assessed using NDVI) and the frequency of rains. This method enables easy, non‐lethal and non‐invasive acquisition of mass data. The equipment is easy to deploy concurrently over large areas. Monitoring by this method has a variety of possible applications, potentially providing a useful early‐warning indicator of body condition to inform management, or providing information about ecological states, such as parturition or the reproductive effort of males. Given the longer and harsher dry seasons experienced in many arid systems in recent decades, and projected in future, this method may provide a straightforward means of monitoring long‐term body condition in animals as a result of environmental change. [ABSTRACT FROM AUTHOR]

Engaging people with controversial and emotive issues that are inherently complex is challenging, especially when those issues are multifaceted or multidisciplinary, span environmental, economic, social, and political contexts, are global in scope, or where circumstances and implications differ spatially. Teaching such issues requires teachers and learners to navigate a challenging landscape of nuance and conflicting perspectives; immersive place-based learning might facilitate more meaningful exploration of such issues, but this has not previously been studied. In a multi-institution international study, we surveyed 164 participants (12 groups; 9 institutions) before and after an immersive fieldtrip in South Africa to assess perceptions on contentious issues. Wilcoxon signed-rank tests showed that participants had statistically significant opinion shifts for 17 of 18 statements, including those where change was likely due to improved knowledge or indicative of deeper attitude shifts. Generalised Linear Modelling revealed that propensity for opinion shifts was not influenced by demographics (age, gender), location (country of origin) or trip type (formal or informal). We conclude that in an increasingly complex world, context-relevant immersive experiences that facilitate deep learning by providing opportunities to explore contentious issues in situ are an ever-more valuable tool, not just for attainment but also for developing personal perspectives and as a catalyst for societal transitions. [ABSTRACT FROM AUTHOR]

Copyright of African Journal of Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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. [ABSTRACT FROM AUTHOR]

Rhino species use their horns in social interactions but also when accessing resources, rubbing and in interspecific defence. The current poaching crisis has seen southern white rhinos (Ceratotherium simum simum) increasingly dehorned as a conservation management practise, but few studies have evaluated whether the procedure has any behavioural effects. This study sought to document and describe horn-contingent behaviours during resource access, wallowing and rubbing in freeranging white rhinos and establish whether dehorning, also known as horn trimming, impacts on their frequency or function. Data were collected through camera trapping and field observations at two sites in South Africa. The results provide no evidence that dehorning disrupts digging behaviours during mineral consumption or wallowing and suggests that dehorning is unlikely to have a strong biological impact on resource access. Furthermore, the frequency of horn-rubbing behaviours did not appear to be influenced by levels of horn growth. This suggests the procedure has a limited impact on these aspects of the species' ecology and provides support that dehorning can be employed as a management tool to reduce poaching in freeranging populations of white rhino. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Copyright of African Journal of Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ticks are obligate blood-feeding ectoparasites that have negative effects on animals through blood loss and vectoring disease. Controlling ticks is a major aspect of wildlife management in many areas, including African savannah where ticks are a long-standing problem. Rotational burning of vegetation is widely thought to reduce ticks but empirical data are lacking. We investigate the effect of block rotational burning on tick populations in a South African wildlife reserve. We measured tick presence/abundance using tick drags in multiple blocks of five different burn ages (areas burned 1, 2, 3, 4 or 5 years previously). We also assessed herbivore diversity using dung as a proxy. Tick presence was highest in areas burned 2-3 years previously. It was lowest in recently-burned areas (probably due to fire-induced mortality or loss of field-layer refugia) and areas burned ≥ 4 years previously (probably because the lack of palatable grass meant herbivore abundance was lower; this is supported by significantly lower herbivore presence in old burns and significant positive correlation between tick numbers and herbivore presence). Burn age and, to a lesser extent, block, were significantly related to tick presence and abundance at both larval and nymph stages. The model that best explained tick numbers, though, included the interaction between burn age and block due to substantial inter-block variability in mid-burn blocks relative to lower variability in blocks at the start or end of the burn cycle. This suggests that burn age and block-specific conditions together influence tick abundance, with habitat heterogeneity likely being an important modifier of the effect burning has on tick numbers. Although annual burning of large areas would not be feasible while maintaining suitable grazing, we suggest that additional annual burning of potential wildlife (and therefore tick) hotspots, such as around waterholes, could reduce tick populations and improve wildlife management. [ABSTRACT FROM AUTHOR]

Copyright of African Journal of Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Illegal hunting (poaching) is a global threat to wildlife. Anti-poaching initiatives are making increasing use of technology, such as infrared thermography (IRT), to support traditional foot and vehicle patrols. To date, the effectiveness of IRT for poacher location has not been tested under field conditions, where thermal signatures are often complex. Here, we test the hypothesis that IRT will increase the distance over which a poacher hiding in African scrub bushveldt can be detected relative to a conventional flashlight. We also test whether any increase in effectiveness is related to the cost and complexity of the equipment by comparing comparatively expensive (22000 USD) and relatively inexpensive (2000 USD) IRT devices. To test these hypotheses we employ a controlled, fully randomised, double-blind procedure to find a poacher in nocturnal field conditions in African bushveldt. Each of our 27 volunteer observers walked three times along a pathway using one detection technology on each pass in randomised order. They searched a prescribed search area of bushveldt within which the target was hiding. Hiding locations were pre-determined, randomised, and changed with each pass. Distances of first detection and positive detection were noted. All technologies could be used to detect the target. Average first detection distance for flashlight was 37.3m, improving by 19.8m to 57.1m using LIRT and by a further 11.2m to 68.3m using HIRT. Although detection distances were significantly greater for both IRTs compared to flashlight, there was no significant difference between LIRT and HIRT. False detection rates were low and there was no significant association between technology and accuracy of detection. Although IRT technology should ideally be tested in the specific environment intended before significant investment is made, we conclude that IRT technology is promising for anti-poaching patrols and that for this purpose low cost IRT units are as effective as units ten times more expensive. [ABSTRACT FROM AUTHOR]

Cape vulture Gyps coprotheres populations have declined across their range due to multiple anthropogenic threats. Their susceptibility to fatal collisions with the expanding power line network and the prevalence of carcasses contaminated with illegal poisons and other threats outside protected areas are thought to be the primary drivers of declines in southern Africa. We used GPS-GSM units to track the movements and delineate the home ranges of five adult (mean ±SD minimum convex polygon area  =  121,655±90,845 km2) and four immature (mean ±SD minimum convex polygon area  =  492,300±259,427 km2) Cape vultures to investigate the influence of power lines and their use of protected areas. The vultures travelled more than 1,000 km from the capture site and collectively entered five different countries in southern Africa. Their movement patterns and core foraging ranges were closely associated with the spatial distribution of transmission power lines and we present evidence that the construction of power lines has allowed the species to extend its range to areas previously devoid of suitable perches. The distribution of locations of known Cape vulture mortalities caused by interactions with power lines corresponded to the core ranges of the tracked vultures. Although some of the vultures regularly roosted at breeding colonies located inside protected areas the majority of foraging activity took place on unprotected farmland. Their ability to travel vast distances very quickly and the high proportion of time they spend in the vicinity of power lines and outside protected areas make Cape vultures especially vulnerable to negative interactions with the expanding power line network and the full range of threats across the region. Co-ordinated cross-border conservation strategies beyond the protected area network will therefore be necessary to ensure the future survival of threatened vultures in Africa. [ABSTRACT FROM AUTHOR]

Field courses are an essential component of the undergraduate experience in many subjects, but are intensive and expensive for participating students. Unpreparedness often means time is used teaching the basics rather than challenging students in exciting and novel situations. Moreover, universal participation is not always possible. Video-based resources covering key concepts and techniques could help participant preparedness and could be used independently by non-participants. This reflective case study details a collaborative project in which students and instructors worked together to make conceptual and instructional videos during a highly applied biosciences field course in South Africa. In 2012, after training from a professional wildlife filmmaker, students were involved in planning, presenting, and filming 25 videos. Students benefited considerably from the filmmaking process as explaining concepts and filming techniques helped reinforce their understanding: an example of "see one, do one, teach one." The online, open-access videos were used by the 2013 cohort to increase preparedness and independently by non-participants to good effect, both internally and at several external institutions. New videos will be added each year to expand the resource base and allow students to gain from the filmmaking experience. This teaching and learning strategy is multidisciplinary, with relevance for a range of subjects. [ABSTRACT FROM AUTHOR]

Terrestrial members of the order Carnivora show great variation in their diet; some specialising in vertebrates, invertebrates, or plant matter, whereas others are omnivores or scavengers (Bekoffet al.,1984). The aardwolfProteles cristatais a highly specialised myrmecovore (Skinner & Chimimba, 2005). We present a first report of a wild aardwolf preying on a vertebrate – captive geeseAnser anser domesticus. [ABSTRACT FROM AUTHOR]

Multiple anthropogenic threats have caused vulture populations to decline globally, with serious ecological and socio-economic implications. The Cape vulture ( Gyps coprotheres ) has declined throughout its range in southern Africa, recently being listed as extinct as a breeding species in Namibia. It has been suggested that climate change might have contributed to the decline of Cape vultures in northern parts of the range. To provide a first assessment of the potential impacts of climate change on the occurrence of Cape vultures, a presence-only environmental niche modelling method (Maxent) was used to predict the spatial occurrence patterns of wild vultures fitted with GPS tracking units in northern Namibia and northern South Africa, under current and future climatic conditions. The models showed high predictive power (AUC > 0.868 ± 0.006), with precipitation seasonality identified as the most important variable for predicting Cape vulture presence. Of the area estimated to be suitable for Cape vultures under current conditions, 28–55% was predicted to become unsuitable under future climate conditions, with a pole-ward shift in the mean centre of the range of 151–333 km and significant range loss from the former breeding range in north-central Namibia and the core breeding range in northern South Africa. The total area of suitable range was predicted to increase in the future due to modelled expansions into grassland and cropland areas where the species has been absent historically. The coverage of suitable areas by protected areas was predicted to decrease from 5.8–7.9% to 2.8–3.8%, suggesting that private land will become increasingly important for Cape vulture conservation. [ABSTRACT FROM AUTHOR]

Cape vulture Gyps coprotheres populations have declined across their range due to multiple anthropogenic threats. Their susceptibility to fatal collisions with the expanding power line network and the prevalence of carcasses contaminated with illegal poisons and other threats outside protected areas are thought to be the primary drivers of declines in southern Africa. We used GPS-GSM units to track the movements and delineate the home ranges of five adult (mean ±SD minimum convex polygon area  =  121,655±90,845 km2) and four immature (mean ±SD minimum convex polygon area  =  492,300±259,427 km2) Cape vultures to investigate the influence of power lines and their use of protected areas. The vultures travelled more than 1,000 km from the capture site and collectively entered five different countries in southern Africa. Their movement patterns and core foraging ranges were closely associated with the spatial distribution of transmission power lines and we present evidence that the construction of power lines has allowed the species to extend its range to areas previously devoid of suitable perches. The distribution of locations of known Cape vulture mortalities caused by interactions with power lines corresponded to the core ranges of the tracked vultures. Although some of the vultures regularly roosted at breeding colonies located inside protected areas the majority of foraging activity took place on unprotected farmland. Their ability to travel vast distances very quickly and the high proportion of time they spend in the vicinity of power lines and outside protected areas make Cape vultures especially vulnerable to negative interactions with the expanding power line network and the full range of threats across the region. Co-ordinated cross-border conservation strategies beyond the protected area network will therefore be necessary to ensure the future survival of threatened vultures in Africa. [ABSTRACT FROM AUTHOR]

Cape vulture Gyps coprotheres populations have declined across their range due to multiple anthropogenic threats. Their susceptibility to fatal collisions with the expanding power line network and the prevalence of carcasses contaminated with illegal poisons and other threats outside protected areas are thought to be the primary drivers of declines in southern Africa. We used GPS-GSM units to track the movements and delineate the home ranges of five adult (mean ±SD minimum convex polygon area = 121,655±90,845 km(2)) and four immature (mean ±SD minimum convex polygon area = 492,300±259,427 km(2)) Cape vultures to investigate the influence of power lines and their use of protected areas. The vultures travelled more than 1,000 km from the capture site and collectively entered five different countries in southern Africa. Their movement patterns and core foraging ranges were closely associated with the spatial distribution of transmission power lines and we present evidence that the construction of power lines has allowed the species to extend its range to areas previously devoid of suitable perches. The distribution of locations of known Cape vulture mortalities caused by interactions with power lines corresponded to the core ranges of the tracked vultures. Although some of the vultures regularly roosted at breeding colonies located inside protected areas the majority of foraging activity took place on unprotected farmland. Their ability to travel vast distances very quickly and the high proportion of time they spend in the vicinity of power lines and outside protected areas make Cape vultures especially vulnerable to negative interactions with the expanding power line network and the full range of threats across the region. Co-ordinated cross-border conservation strategies beyond the protected area network will therefore be necessary to ensure the future survival of threatened vultures in Africa.