87 research outputs found
A novel record of aardwolf Proteles cristata feeding behaviour
Terrestrial members of the order Carnivora show great variation in their diet; some specialising on vertebrates, invertebrates, or plant matter, whereas others are omnivores or scavengers (Bekoff et al, 1984). The aardwolf Proteles cristata is a highly specialised myrmecovore (Skinner and Chimimba 2005). We present a first report of a wild aardwolf preying on a vertebrate - captive geese Anser anser domesticus
Recommended from our members
Beneficial land management for hedgehogs (Erinaceus europaeus) in the United Kingdom
Hedgehogs (Erinaceus europaeus) are traditionally thought of as being a rural dwelling species, associated with rural and agricultural landscapes across Europe. However, recent studies have highlighted that hedgehogs are more likely to be found in urban than rural habitats in the United Kingdom. Here, we review the status of rural hedgehog populations across the UK and evaluate the potential benefits of agri-environment schemes for hedgehog persistence, while highlighting a lack of empirical evidence that agri-environment options will benefit hedgehog populations. Our synthesis has implications for future conservation strategies for hedgehogs and insectivorous mammals living in agricultural landscapes, and calls for more empirical studies on agri-environment options and their potential benefits to hedgehogs
Comparative efficacy of sign surveys, spotlighting and audio playbacks in a landscape-scale carnivore survey
Many carnivores are difficult and labour-intensive to detect, often leading to prohibitively high effort and cost in large-scale surveys. However, such studies provide information that is important for effective management and conservation. Here, we evaluate the suitability of three survey methods for landscape-scale multi-species monitoring. We compare sign surveys, spotlighting, and audio playbacks in terms of detection efficiency, precision, effort, and cost. Sign surveys out-performed the other methods in all comparison criteria, although supplementary methods were needed for some species and sites. We found that using established analysis techniques, robust landscape-scale abundance estimates would require unrealistically high effort and cost. Occupancy estimation required considerably lower sample sizes and was therefore more economical. We conclude that sign-based occupancy estimates constitute a versatile and efficient option for future large-scale, multi-species carnivore surveys
The breeding performance of raptors in urban landscapes: a review and meta-analysis
Global urbanisation is rapidly increasing and can have profound impacts on wild flora and fauna. For many species, the impacts are detrimental and irreversible, whereas others are able to colonise and apparently thrive in these novel, human-made environments. Raptors are particularly susceptible to changes in the environment due to their position at the end of the food chain, yet some species are increasingly associated with towns and cities. To explore the impact of urbanisation on raptors, we reviewed the literature and compared breeding performance in urban and rural populations globally. In general, raptors began breeding earlier and had larger brood sizes in urban compared to rural environments. However, some of these raptors also fledged fewer young in urban habitats, apparently caused largely by a lack of prey and, in some cases, increased human disturbance. As such, urban environments may act as ecological traps for some raptor species. Species differed in their response to urbanisation. In particular, specialist bird predators such as Peregrine Falcons (Falco peregrinus) had a higher breeding performance (clutch size, brood size, number to fledge and nest success) and showed a positive response to urbanisation compared to those that predate on small mammals, such as Eurasian Kestrels (F. tinnunculus), which showed a negative response. This suggests that prey availability is one of the most important determinants of the success of urban-nest- ing raptors. We demonstrate a need for continued research into the breeding performance of raptors that live in urban environments, and stress the importance of focusing on the reasons for any differences in breeding performance between urban and non-urban environments in order to aid conservation and management efforts for this iconic bird grou
Recommended from our members
Breeding performance of an apex predator, the peregrine falcon, across urban and rural landscapes
Urban environments present wildlife with major challenges and yet surprising numbers of species have colonised towns and cities globally. Despite the growing realisation that urban centres can be important habitats for wildlife, why some species do better than others in urban environments remains poorly understood. Here, we compare the breeding performance of an apex predator, the peregrine falcon (Falco peregrinus), in urban and rural environments, and test whether variation in reproductive success between and within environments is driven by prey. Historical breeding data were collected from raptor study groups across Great Britain between 2006 and 2016, from 22 urban and 58 rural nest sites, involving 101 and 326 nesting attempts, respectively. Prey density, biomass and diversity around the individual nests was estimated using modelled estimates from a national bird census. Urban peregrines produced more fledglings and had a higher overall nesting success (i.e. whether a nesting attempt was successful or unsuccessful) than rural peregrines. Prey density and biomass were significantly higher, and diversity significantly lower, in the urban sites, and explained the variation in reproductive success within both the urban and rural environments. Therefore, urban environments in Great Britain appear to provide peregrine falcons with superior habitats in terms of prey availability compared to rural habitats. We conclude that some apex predators can benefit from urban environments and that urban planning has the potential to benefit biodiversity across many trophic levels
Recommended from our members
The influence of large predators on the feeding ecology of two African mesocarnivores: the black-backed jackal and the brown hyaena
Interactions between apex and mesopredators and their impacts on prey populations have been well documented, while the influence of apex predators such as lions on carrion availability and the subsequent impacts at lower trophic levels are not fully understood. Here we assess dietary overlap between two sympatric carnivores (brown hyaena, Parahyaena brunnea, and black-backed jackal, Canis mesomelas) in neighbouring reserves with and without apex predators (lions, Panthera leo,and wild dog, Lycaon pictus). We investigate whether apex predators facilitate niche partitioning between mesocarnivores by creating additional scavenging opportunities through predatory activity. We found that brown hyaena density was higher in the area with apex predators, while black-backed jackal density was higher in the area without apex predators. Black-backed jackal scats contained broadly similar dietary items at both sites, while large mammal remains occurred significantly more frequently in brown hyaena scats collected inthe presence of apex predators. In the absence of apex predators there was a markedly higher degree of overlap between brown hyaena and jackal diets, suggesting increased levels of inter-specific competition. Our results suggest that apex predators potentially reduce levels of inter-specific competition for food between mesocarnivores by providing additional scavenging opportunities for specialist scavengers such as brown hyaena
Recommended from our members
Ecologists need robust survey designs, sampling and analytical methods
1. Research that yields conflicting results rightly causes controversy. Where methodological weaknesses are apparent, there is ready opportunity for discord within the scientific community, which may undermine the entire study.
2. We use the debate about the role of dingoes Canis dingo in conservation in Australia as a case study for a phenomenon that is relevant to all applied ecologists, where conflicting results have been published in high quality journals and yet the problems with the methods used in these studies have led to significant controversy.
3. To alleviate such controversies, scientists need to use robust methods to ensure that their results are repeatable and defendable. To date, this has not occurred in Australia’s dingo debate due to the use of unvalidated indices that rely on unsupported assumptions.
4. We highlight the problems that poor methods have caused in this debate. We also reiterate our recommendations for practitioners, statisticians and researchers to work together to develop long-term, multi-site experimental research programmes using robust methods to understand the impacts of dingoes on mesopredators.
5. Synthesis & applications. Incorporating robust methods and appropriate experimental designs are needed to ensure that conservation actions are appropriately focused and are supported with robust results. Such actions will go
a long way towards resolving the debate about the role of dingoes in conservation in Australia, and other, ecological debates
Recommended from our members
A prickly problem: developing a volunteer-friendly tool for monitoring populations of a terrestrial urban mammal, the West European hedgehog (Erinaceus europaeus)
Across Europe, hedgehogs (Erinaceus europaeus) appear to be in decline in both urban and rural landscapes. Current methods used to monitor urban populations are, however, associated with several potential limitations. In this study, we conducted hedgehog footprint-tunnel surveys in 219 residential gardens across Reading, UK between May–September in 2013 and/or 2014; gardens were surveyed for five continuous days. Single-species occupancy models were used to investigate factors influencing hedgehog occupancy and two-species occupancy models were used to estimate a species interaction factor (SIF) between hedgehogs and (a) badgers (Meles meles), (b) foxes (Vulpes vulpes) and (c) dogs (Canis familiaris). The five-day survey protocol was associated with a false-absence error rate of 0.1–0.4%, indicating that it was a reliable method for determining hedgehog presence; conversely, 34.7% of householders were not able to correctly predict hedgehog presence or absence. Hedgehogs were widely distributed across Reading, but detected in only 32–40% of gardens. None of the within-garden or outside-garden factors investigated significantly affected hedgehog occupancy in the single-species models, but the two-species models indicated that badgers (SIF = 0.471 ± 0.188), but not foxes (SIF = 0.954 ± 0.048) or dogs (SIF = 0.780 ± 0.228), negatively affected the presence of hedgehogs in gardens, although not significantly. Overall, footprint-tunnels represent a viable field method for monitoring urban hedgehog populations, however, other approaches are required to identify factors that make gardens "hedgehog friendly"
An assessment of diet overlap of two mesocarnivores in the North-West Province, South Africa
We used scat analysis to study the diet of two sympatric medium-sized carnivores: brown hyaena and black-backed jackal, in the NorthWest Province of South Africa. Seven major dietary categories were identified from the scats, with mammal remains being most common for both species. Brown hyaena scats contained more large mammal remains, which together with the presence of invertebrates (in 50% of all brown hyaena scats), suggests that they mainly scavenged. Jackal scats contained a higher proportion of small mammal remains, suggesting that jackals actively hunted more often than brown hyaenas did. The diets differed significantly between the two species, even though diet overlap was fairly high (0.79). Further analysis, albeit based on small sample sizes, suggests that diet of these mesopredators differ between protected reserves with apex predators and unprotected areas without apex predators, thus confounding generalizations. Further studies are therefore required to investigate possible mesopredator release when apex predators are absent
- …