Time filter

Source Type

Apps P.,Paul G Allen Family Foundation Laboratory for Wildlife Chemistry | Mmualefe L.,Paul G Allen Family Foundation Laboratory for Wildlife Chemistry | McNutt J.W.,Botswana Predator Conservation Trust
Journal of Chemical Ecology | Year: 2012

Gas chromatography/mass spectrometry was used to identify 103 organic compounds from urine, feces, anal glands, and preputial glands of free-ranging African wild dogs, Lycaon pictus. Aliphatic acids were the dominant class of compound in all materials. In addition to aliphatic acids, urine contained dimethyl sulfone, 1,3-propanediol, benzoic acid, 1-methyl-2,4-imidazolidinedione, and squalene as major components: feces contained indole and cholesterol; and both contained 2-piperidone, phenol, 4-methyl phenol, benzeneacetic acid, and benzenepropanoic acid and other compounds. Anal gland secretion was particularly rich in cholesterol and fatty acids, and preputial gland secretion rich in squalene. A large majority of the identified compounds have been reported from other mammals, including species sympatric with African wild dogs. Eleven of the African wild dog components have not been reported previously from mammals and have not been found in sympatric species; one component, 1-methylimidazole-5-carboxaldehyde has not been reported previously as a natural product. In the chemical profiles of their urine, feces, and anal gland secretion African wild dogs differ markedly from other canids. © 2012 Springer Science+Business Media New York.

Broekhuis F.,University of Oxford | Grunewalder S.,University College London | McNutt J.W.,Botswana Predator Conservation Trust | Macdonald D.W.,University of Oxford
Behavioral Ecology | Year: 2014

Foraging requirements and predation risk shape activity patterns and temporal behavior patterns widely across taxa. Although this has been extensively studied in small mammals, the influence of predation and prey acquisition on the activity and behavior of large carnivores has received little attention. The diurnal activity described as typical for cheetahs (Acinonyx jubatus) has been explained in terms of their avoidance of antagonistic interactions with other larger predators. However, a recent study revealed that cheetahs are frequently active at night, especially during periods of full moon. Being both predator and "prey" in an environment with comparatively high densities of larger and competitively dominant nocturnal predator species, we investigated whether cheetah nocturnal behavior could be explained by favorable conditions for 1) predator avoidance or 2) prey acquisition. We used a data set of continuously recorded behavior created using machine-learning techniques on behavioral data collected in the field to transform recorded 2D activity values from radio-collars into 3 distinct behavioral states (feeding, moving, and resting). We found that 32.5% of cheetah feeding behavior occurred at night and that, in the dry season, nocturnal feeding behavior was positively correlated with moonlight intensity. Our results suggest that nocturnal and circalunar behavior of cheetahs is driven by optimal hunting conditions, outweighing the risks of encountering other predators. Using novel methodology, the results provide new insights into the temporal distribution of behavior, contributing to our understanding of the importance of moonlight and season on the behavior patterns of diurnal species. © 2014 © The Author 2014. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved.

Pomilia M.A.,University of Leeds | Mcnutt J.W.,Botswana Predator Conservation Trust | Jordan N.R.,University of New South Wales | Jordan N.R.,Wildlife Conservation Society
Journal of Mammalogy | Year: 2015

Extinction risk in African wild dogs (Lycaon pictus) has been linked to their wide-ranging movement behavior. However, drivers of variability in African wild dog ranging are not well understood. This study examines the effects of intrinsic and extrinsic factors on ranging patterns and describes scale-dependent and intra-annual variation in the ranging of 5 packs of African wild dogs in the Okavango Delta from 2007 to 2010. 95% fixed kernel home ranges ( = 739 ± 81 km2) and daily step lengths ( = 8.5 ± 0.5 km) in this study are larger than have generally been reported for African wild dogs elsewhere. Little seasonal variation in daily ranging distances was observed despite home-range contractions during denning to 27% of packs' ranges outside the denning period. During nondenning periods, litter size was the most influential driver of ranging patterns, with large litters associated with reduced pack movements and smaller home ranges at all temporal scales. Pack size was also a significant driver of home-range size (but not daily distance travelled) at weekly timescales, where larger packs utilized smaller ranges. Daily temperatures were inversely related to home-range size and step length at short timescales, while higher flood levels were related to reduced ranging distances at intermediate timescales. Our results indicate that extrinsic drivers of African wild dog ranging behavior tend to be scale dependent, while intrinsic factors may be more influential for ranging patterns than previously reported. © 2015 American Society of Mammalogists.

Cozzi G.,University of Zurich | Broekhuis F.,Botswana Predator Conservation Trust | Broekhuis F.,University of Oxford | McNutt J.W.,Botswana Predator Conservation Trust | Schmid B.,University of Zurich
Biodiversity and Conservation | Year: 2013

Top predators significantly impact ecosystem dynamics and act as important indicator species for ecosystem health. However, reliable density estimates for top predators, considered necessary for the development of management plans and ecosystem monitoring, are challenging to obtain. This study aims to establish baseline density estimates for two top predators, spotted hyena and lion, in the Okavango Delta in northern Botswana. Using calling stations, we surveyed free-ranging populations of the two species and investigated methodological variables that might influence results about distributions and densities, including habitat type, seasonality, and different types of playback sounds. Calling stations were distributed over a survey area of approximately 1,800 km2 characterized by three major habitat types: mopane woodland, floodplain and mixed acacia sandveld. Results indicate spotted hyenas were evenly distributed independent of habitat type and season throughout the survey area with an overall density estimate of 14.4 adults/100 km2. In contrast, lion distribution and density varied significantly with habitat and season. Lion density in the prey-poor mopane woodland was near zero, while in the comparatively prey-rich floodplains it was estimated at 23.1 individuals/100 km2 resulting in a weighted average density of 5.8 individuals/100 km2 across the entire study area. In testing the effect of varying playback sounds we found that both species were significantly more likely to respond to calls of conspecifics. Our results show how several methodological variables may influence density estimates and emphasize the importance of standardized calling-station survey methods to allow consistent replication of surveys and comparison of results that can be used for landscape-scale monitoring of large predator species. © 2013 Springer Science+Business Media Dordrecht.

Cozzi G.,University of Zurich | Broekhuis F.,Botswana Predator Conservation Trust | Broekhuis F.,University of Oxford | Mcnutt J.W.,Botswana Predator Conservation Trust | Schmid B.,University of Zurich
Journal of Animal Ecology | Year: 2013

Summary: Physical barriers contribute to habitat fragmentation, influence species distribution and ranging behaviour, and impact long-term population viability. Barrier permeability varies among species and can potentially impact the competitive balance within animal communities by differentially affecting co-occurring species. The influence of barriers on the spatial distribution of species within whole communities has nonetheless received little attention. During a 4-year period, we studied the influence of a fence and rivers, two landscape features that potentially act as barriers on space use and ranging behaviour of lions Panthera leo, spotted hyenas Crocuta crocuta, African wild dogs Lycaon pictus and cheetahs Acinonyx jubatus in Northern Botswana. We compared the tendencies of these species to cross the barriers using data generated from GPS-radio collars fitted to a total of 35 individuals. Barrier permeability was inferred by calculating the number of times animals crossed a barrier vs. the number of times they did not cross. Finally, based on our results, we produced a map of connectivity for the broader landscape system. Permeability varied significantly between fence and rivers and among species. The fence represented an obstacle for lions (permeability = 7·2%), while it was considerably more permeable for hyenas (35·6%) and wild dogs and cheetahs (≥50%). In contrast, the rivers and associated floodplains were relatively permeable to lions (14·4%) while they represented a nearly impassable obstacle for the other species (<2%). The aversion of lions to cross the fence resulted in a relatively lion-free habitat patch on one side of the fence, which might provide a potential refuge for other species. For instance, the competitively inferior wild dogs used this refuge significantly more intensively than the side of the fence with a high presence of lions. We showed that the influence of a barrier on the distribution of animals could potentially result in a broad-scale modification of community structure and ecology within a guild of co-occurring species. As habitat fragmentation increases, understanding the impact of barriers on species distributions is thus essential for the implementation of landscape-scale management strategies, the development and maintenance of corridors and the enhancement of connectivity. © 2013 British Ecological Society.

Discover hidden collaborations