7 results on '"Broekhuis F"'
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2. An insight into the prey spectra and livestock predation by cheetahs in Kenya using faecal DNA metabarcoding.
- Author
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Thuo D, Broekhuis F, Furlan E, Bertola LD, Kamau J, and Gleeson DM
- Subjects
- Animals, Animals, Wild, DNA genetics, Diet, Ecosystem, Female, Kenya, Male, Acinonyx physiology, Feces chemistry, Livestock genetics, Mammals genetics, Predatory Behavior
- Abstract
Dietary composition is a fundamental part of animal ecology and an important component of population dynamics. Therefore, obtaining accurate information on what an animal consumes is important for conservation planning, especially for wild large carnivores that exist in human-dominated landscapes where they are prone to direct conflicts with local people. We used faecal DNA metabarcoding to identify the vertebrate taxa commonly predated on by cheetahs (Acinonyx jubatus) with an emphasis on domestic taxa and determine the drivers of livestock predation by cheetahs residing in the Maasai Mara and Amboseli ecosystems which are important population strongholds in southern Kenya. From 84 cheetah faeces that we analysed, a total of 14 prey taxa were identified, including birds, wild and domestic mammals. The livestock taxa identified in cheetah faeces occurred at moderate frequency (12.8%) and the results showed that livestock predation was influenced neither by the sex of the cheetah nor by season. In general, our study shows that cheetahs prey on a diverse range of prey taxa including birds, wild ungulates of various sizes and occasionally on domestic animals, and that the faecal DNA metabarcoding approach represents a valuable complement to traditional dietary analysis methods., (Copyright © 2020 Elsevier GmbH. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
3. Food from faeces: Evaluating the efficacy of scat DNA metabarcoding in dietary analyses.
- Author
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Thuo D, Furlan E, Broekhuis F, Kamau J, Macdonald K, and Gleeson DM
- Subjects
- Animals, Acinonyx physiology, DNA analysis, DNA Barcoding, Taxonomic methods, Diet veterinary, Feces chemistry
- Abstract
Scat DNA metabarcoding is increasingly being used to track the feeding ecology of elusive wildlife species. This approach has greatly increased the resolution and detection success of prey items contained in scats when compared with other classical methods. However, there have been few studies that have systematically tested the applicability and reliability of this approach to study the diet of large felids species in the wild. Here we assessed the effectiveness of this approach in the cheetah Acinonyx jubatus. We tested how scat degradation, meal size, prey species consumed and feeding day (the day a particular prey was consumed) influenced prey DNA detection success in captive cheetahs. We demonstrated that it is possible to obtain diet information from 60-day old scats using genetic approaches, but the efficiency decreased over time. Probability of species-identification was highest for food items consumed one day prior to scat collection and the probability of being able to identify the species consumed increased with the proportion of the prey consumed. Detection success varied among prey species but not by individual cheetah. Identification of prey species using DNA detection methods from a single consumption event worked for samples collected between 8 and 72 hours post-feeding. Our approach confirms the utility of genetic approaches to identify prey species in scats and highlight the need to account for the systematic bias in results to control for possible scat degradation, feeding day, meal size and prey species consumed especially in the wild-collected scats., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2019
- Full Text
- View/download PDF
4. Using GPS collars to investigate the frequency and behavioural outcomes of intraspecific interactions among carnivores: A case study of male cheetahs in the Maasai Mara, Kenya.
- Author
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Broekhuis F, Madsen EK, Keiwua K, and Macdonald DW
- Subjects
- Animals, Geographic Information Systems, Kenya, Male, Remote Sensing Technology methods, Acinonyx physiology, Animal Communication, Homing Behavior physiology, Remote Sensing Technology instrumentation, Wearable Electronic Devices
- Abstract
Intraspecific interactions between individuals or groups of individuals of the same species are an important component of population dynamics. Interactions can be static, such as spatial overlap, or dynamic based on the interactions of movements, and can be mediated through communication, such as the deployment of scent marks. Interactions and their behavioural outcomes can be difficult to determine, especially for species that live at low densities. With the use of GPS collars we quantify both static and dynamic interactions between male cheetahs (Acinonyx jubatus) and the behavioural outcomes. The 99% home-ranges of males overlapped significantly while there was little overlap of the 50% home-ranges. Despite this overlap, male cheetahs rarely came into close proximity of one another, possibly because presence was communicated through frequent visits to marking posts. The minimum distance between individuals in a dyad ranged from 89m to 196m but the average proximity between individuals ranged from 17,145 ± 6,865m to 26,367 ± 11,288m. Possible interactions took place more frequently at night than by day and occurred mostly in the 50% home-range of one individual of a dyad or where cores of both individuals overlapped. After a possible encounter male cheetahs stayed in close proximity to each other for up to 6 hours, which could be the result of a territory defence strategy or the presence of a receptive female. We believe that one of the encounters between a singleton and a 5-male coalition resulted in the death of the singleton. Our results give new insights into cheetah interactions, which could help our understanding of ecological processes such as disease transmission., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2019
- Full Text
- View/download PDF
5. The global decline of cheetah Acinonyx jubatus and what it means for conservation.
- Author
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Durant SM, Mitchell N, Groom R, Pettorelli N, Ipavec A, Jacobson AP, Woodroffe R, Böhm M, Hunter LT, Becker MS, Broekhuis F, Bashir S, Andresen L, Aschenborn O, Beddiaf M, Belbachir F, Belbachir-Bazi A, Berbash A, Brandao de Matos Machado I, Breitenmoser C, Chege M, Cilliers D, Davies-Mostert H, Dickman AJ, Ezekiel F, Farhadinia MS, Funston P, Henschel P, Horgan J, de Iongh HH, Jowkar H, Klein R, Lindsey PA, Marker L, Marnewick K, Melzheimer J, Merkle J, M'soka J, Msuha M, O'Neill H, Parker M, Purchase G, Sahailou S, Saidu Y, Samna A, Schmidt-Küntzel A, Selebatso E, Sogbohossou EA, Soultan A, Stone E, van der Meer E, van Vuuren R, Wykstra M, and Young-Overton K
- Subjects
- Africa, Animals, Asia, Biodiversity, Computer Simulation, Extinction, Biological, Models, Biological, Population Dynamics trends, Risk Factors, Acinonyx, Conservation of Natural Resources
- Abstract
Establishing and maintaining protected areas (PAs) are key tools for biodiversity conservation. However, this approach is insufficient for many species, particularly those that are wide-ranging and sparse. The cheetah Acinonyx jubatus exemplifies such a species and faces extreme challenges to its survival. Here, we show that the global population is estimated at ∼7,100 individuals and confined to 9% of its historical distributional range. However, the majority of current range (77%) occurs outside of PAs, where the species faces multiple threats. Scenario modeling shows that, where growth rates are suppressed outside PAs, extinction rates increase rapidly as the proportion of population protected declines. Sensitivity analysis shows that growth rates within PAs have to be high if they are to compensate for declines outside. Susceptibility of cheetah to rapid decline is evidenced by recent rapid contraction in range, supporting an uplisting of the International Union for the Conservation of Nature (IUCN) Red List threat assessment to endangered. Our results are applicable to other protection-reliant species, which may be subject to systematic underestimation of threat when there is insufficient information outside PAs. Ultimately, conserving many of these species necessitates a paradigm shift in conservation toward a holistic approach that incentivizes protection and promotes sustainable human-wildlife coexistence across large multiple-use landscapes., Competing Interests: The authors declare no conflict of interest.
- Published
- 2017
- Full Text
- View/download PDF
6. Counting Cats: Spatially Explicit Population Estimates of Cheetah (Acinonyx jubatus) Using Unstructured Sampling Data.
- Author
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Broekhuis F and Gopalaswamy AM
- Subjects
- Animals, Bayes Theorem, Female, Kenya, Male, Population Density, Acinonyx, Models, Theoretical
- Abstract
Many ecological theories and species conservation programmes rely on accurate estimates of population density. Accurate density estimation, especially for species facing rapid declines, requires the application of rigorous field and analytical methods. However, obtaining accurate density estimates of carnivores can be challenging as carnivores naturally exist at relatively low densities and are often elusive and wide-ranging. In this study, we employ an unstructured spatial sampling field design along with a Bayesian sex-specific spatially explicit capture-recapture (SECR) analysis, to provide the first rigorous population density estimates of cheetahs (Acinonyx jubatus) in the Maasai Mara, Kenya. We estimate adult cheetah density to be between 1.28 ± 0.315 and 1.34 ± 0.337 individuals/100km2 across four candidate models specified in our analysis. Our spatially explicit approach revealed 'hotspots' of cheetah density, highlighting that cheetah are distributed heterogeneously across the landscape. The SECR models incorporated a movement range parameter which indicated that male cheetah moved four times as much as females, possibly because female movement was restricted by their reproductive status and/or the spatial distribution of prey. We show that SECR can be used for spatially unstructured data to successfully characterise the spatial distribution of a low density species and also estimate population density when sample size is small. Our sampling and modelling framework will help determine spatial and temporal variation in cheetah densities, providing a foundation for their conservation and management. Based on our results we encourage other researchers to adopt a similar approach in estimating densities of individually recognisable species.
- Published
- 2016
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7. Movement activity based classification of animal behaviour with an application to data from cheetah (Acinonyx jubatus).
- Author
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Grünewälder S, Broekhuis F, Macdonald DW, Wilson AM, McNutt JW, Shawe-Taylor J, and Hailes S
- Subjects
- Animals, Feeding Behavior physiology, Female, Male, Seasons, Support Vector Machine, Acinonyx physiology, Behavior, Animal physiology, Movement physiology
- Abstract
We propose a new method, based on machine learning techniques, for the analysis of a combination of continuous data from dataloggers and a sampling of contemporaneous behaviour observations. This data combination provides an opportunity for biologists to study behaviour at a previously unknown level of detail and accuracy; however, continuously recorded data are of little use unless the resulting large volumes of raw data can be reliably translated into actual behaviour. We address this problem by applying a Support Vector Machine and a Hidden-Markov Model that allows us to classify an animal's behaviour using a small set of field observations to calibrate continuously recorded activity data. Such classified data can be applied quantitatively to the behaviour of animals over extended periods and at times during which observation is difficult or impossible. We demonstrate the usefulness of the method by applying it to data from six cheetah (Acinonyx jubatus) in the Okavango Delta, Botswana. Cumulative activity data scores were recorded every five minutes by accelerometers embedded in GPS radio-collars for around one year on average. Direct behaviour sampling of each of the six cheetah were collected in the field for comparatively short periods. Using this approach we are able to classify each five minute activity score into a set of three key behaviour (feeding, mobile and stationary), creating a continuous behavioural sequence for the entire period for which the collars were deployed. Evaluation of our classifier with cross-validation shows the accuracy to be 83%-94%, but that the accuracy for individual classes is reduced with decreasing sample size of direct observations. We demonstrate how these processed data can be used to study behaviour identifying seasonal and gender differences in daily activity and feeding times. Results given here are unlike any that could be obtained using traditional approaches in both accuracy and detail.
- Published
- 2012
- Full Text
- View/download PDF
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