Bettina Wachter | Leibniz Institute for Zoo and Wildlife Research (original) (raw)

Papers by Bettina Wachter

Cheetahs: Biology and Conservation, 2018

Cheetahs have unique social and mating systems, as well as hunting techniques. Males are either t... more Cheetahs have unique social and mating systems, as well as hunting techniques. Males are either territory holders defending small territories or floaters roaming in large, overlapping, undefended home ranges. Both spatial tactics are adopted by solitary males or coalitions of males. Females are solitary unless accompanied by offspring. They give birth to two to six cubs, which are hidden in a lair for the first 2 months. In ecosystems with other large predator species, cheetahs adopt several predator avoidance behaviors. Nevertheless, cubs can suffer from high mortality by lions and spotted hyenas, and adult cheetahs may lose kills to kleptoparasites. Cheetahs primarily hunt abundant, small to medium sized prey animals using high-speed chases over short distances. They mainly communicate with vocalization and olfaction, often using prominent landmarks for scent marking. Given the increasing human pressure on carnivores, conservation efforts would benefit from behavioral data in human inhabited areas.

Current tracking technology such as GPS data loggers allows biologists to remotely collect large ... more Current tracking technology such as GPS data loggers allows biologists to remotely collect large amounts of movement data for a large variety of species. Extending, and often replacing interpretation based on observation, the analysis of the collected data supports research on animal behaviour, on impact factors such as climate change and human intervention on the globe, as well as on conservation programs. However, this analysis is difficult, due to the nature of the research questions and the complexity of the data sets. It requires both automated analysis, for example, for the detection of behavioural patterns, and human inspection, for example, for interpretation, inclusion of previous knowledge, and for conclusions on future actions and decision making. For this analysis and inspection, the movement data needs to be put into the context of environmental data, which helps to interpret the behaviour. Thus, a major challenge is to design and develop methods and intuitive interface...

Additional file 1: Table S1. Data table of ELISA and IB results containing information on all sam... more Additional file 1: Table S1. Data table of ELISA and IB results containing information on all samples (species, suborder, site, ELISA, IB and final results for T. gondii, N. caninum and B. besnoiti, respectively).

Namibia is thought to host the largest population of free-ranging cheetahs Acinonyx jubatus and t... more Namibia is thought to host the largest population of free-ranging cheetahs Acinonyx jubatus and the majority of this po-pulation inhabits commercial farm-land (Morsbach 1987). Some farmers consider that cheetahs prey on both livestock and wild herbivores that are valuable for trophy hunting, and this perceived offtake has generated conflict leading to the indiscrimina-te elimination of cheetahs from some farms (Marker et al. 1996). To help assess the economic cost of cheetahs on commercial farmland, informati-on on the proportion of different prey species in their diet is required. As it is difficult to directly assess the diet of farmland cheetahs due to their extremely shy behaviour and the small chance of finding fresh prey carcasses (Fig. 1.), we assessed the diet of chee-tahs on Namibian farmland by applying a simple method originally devised for police forensic science. The method is based on the unique imprint of hair from different prey species in cheetah faeces (e.g. Keogh ...

doi: 10.3389/fmicb.2014.00526 Oligotyping reveals differences between gut microbiomes of free-ran... more doi: 10.3389/fmicb.2014.00526 Oligotyping reveals differences between gut microbiomes of free-ranging sympatric Namibian carnivores (Acinonyx

Life history theory predicts that mothers should provide their offspring with a privileged upbrin... more Life history theory predicts that mothers should provide their offspring with a privileged upbringing if this enhances their offspring ’ s and their own fitness. In many mammals, highranking mothers provide their offspring with a privileged upbringing. Whether dispersing sons gain fitness benefits during adulthood from such privileges (a ‘ silver spoon ’ effect) has rarely been examined. In this paper, we show that in the complex, female-dominated society of spotted hyaenas, high-born sons grew at higher rates, were more likely to disperse to clans offering the best fitness prospects, started reproducing earlier and had a higher reproductive value than did lower-born sons. This illustrates the evolutionary importance of maternal effects even in societies in which male size or fighting ability does not influence fitness. By demonstrating for the first time in a non-human mammal that maternal status influences immigration patterns, the study also advances our understanding of two key ...

Proceedings of the 12th International Symposium on Visual Information Communication and Interaction

Recent advances in tracking technology allow biologists to collect large amounts of movement data... more Recent advances in tracking technology allow biologists to collect large amounts of movement data for a variety of species. Analysis of the collected data supports research on animal behaviour, influence of impact factors such as climate change and human intervention, as well as conservation programs. Analysis of the movement data is difficult, due to the nature of the research questions and the complexity of the data sets. It requires both automated analysis, e.g. for the detection of behavioural patterns, and human inspection, e.g. for interpretation, inclusion of previous knowledge, and for conclusions on future actions and decision making. We present a concept and implementation for the visual analysis of cheetah movement data in a web-based fashion that allows usage both in the field and in office environments.

corticosteroid concentrations in Serengeti females were significantly higher than in Ngorongoro f... more corticosteroid concentrations in Serengeti females were significantly higher than in Ngorongoro females. Energy expenditure by lactation is exceptionally high in spotted hyenas and this may be reflected in their corticosteroid levels. The faecal corticosteroid levels in both populations were higher in lactating than in non-lactating females. During periods of social stability, faecal corticosteroid concentrations increased in non-lactating females but not in lactating females as social status declined. Lactating Serengeti females had significantly higher faecal corticosteroid concentrations during periods with acute severe social stress than during periods without, indicating that the HPA axis is sensitive to social stimuli even in lactating females. So far few studies have used non-invasive monitoring methods for assessing social stress in freeranging animals. This study demonstrates for the first time, to the authors' knowledge, that corticosteroid concentrations may differ be...

Namibia is thought to host the largest population of freeranging cheetahs Acinonyx jubatus and th... more Namibia is thought to host the largest population of freeranging cheetahs Acinonyx jubatus and the majority of this population inhabits commercial farmland (Morsbach 1987). Some farmers consider that cheetahs prey on both livestock and wild herbivores that are valuable for trophy hunting, and this perceived offtake has generated conflict leading to the indiscriminate elimination of cheetahs from some farms (Marker et al. 1996). To help assess the economic cost of cheetahs on commercial farmland, information on the proportion of different prey species in their diet is required.

Parasites & Vectors

Background Improved knowledge on vector-borne pathogens in wildlife will help determine their eff... more Background Improved knowledge on vector-borne pathogens in wildlife will help determine their effect on host species at the population and individual level and whether these are affected by anthropogenic factors such as global climate change and landscape changes. Here, samples from brown hyenas (Parahyaena brunnea) from Namibia (BHNA) and spotted hyenas (Crocuta crocuta) from Namibia (SHNA) and Tanzania (SHTZ) were screened for vector-borne pathogens to assess the frequency and genetic diversity of pathogens and the effect of ecological conditions and host taxonomy on this diversity. Methods Tissue samples from BHNA (n = 17), SHNA (n = 19) and SHTZ (n = 25) were analysed by PCRs targeting Anaplasmataceae, Rickettsia spp., piroplasms, specifically Babesia lengau-like piroplasms, Hepatozoidae and filarioids. After sequencing, maximum-likelihood phylogenetic analyses were conducted. Results The relative frequency of Anaplasmataceae was significantly higher in BHNA (82.4%) and SHNA (10...

Noninvasive techniques hold many potential advantages including limiting capture and handling str... more Noninvasive techniques hold many potential advantages including limiting capture and handling stress in wild animals. Scat (feces) samples provide a geophysical landmark and are a biological source for a range of biomedical and ecological questions. The cheetah’s low densities lead to difficulties to study them in the wild, including challenges to find scat samples. Use of professionally trained scat-detection dogs can substantially increase the effectiveness of scat searches. Species, individual identity, and sex of the individual can be determined from scat samples using molecular genetic techniques. Once the information about the individual has been obtained, follow-up questions can be asked. For instance diet composition can be determined using prey species hair found in the scat, and endocrine analyses can provide information about the health and physiology at an individual or population level. Because of their noninvasiveness, these techniques can also be used for long-term mo...

Cheetahs: Biology and Conservation

Considerable research has been conducted on cheetah ecology. Cheetahs can exist in a wide variety... more Considerable research has been conducted on cheetah ecology. Cheetahs can exist in a wide variety of habitats from thick scrub to open grassland, and habitat selection is based on a variety of factors, including visibility, prey density, and avoidance of competitively superior predators. Cheetahs naturally occur at low densities and require a prey base of small to medium-sized ungulates that can be consumed rapidly, minimizing the risks for cheetahs of being detected by larger carnivores that can usurp their kills. Cheetahs exhibit wide ranging movements and large home ranges—over 2000 km 2 in some areas. Reported densities generally range from 0.3 to 3.0 adult cheetahs per 100 km 2 . The species distribution, density, and activity patterns are impacted by human activities and the presence of larger carnivores. Understanding cheetah habitat requirements and movement ecology, especially pertaining to long-distance movements, will become progressively more important as the cheetah’s range becomes increasingly fragmented.

Proceedings of the National Academy of Sciences

Human–wildlife conflicts occur worldwide. Although many nonlethal mitigation solutions are availa... more Human–wildlife conflicts occur worldwide. Although many nonlethal mitigation solutions are available, they rarely use the behavioral ecology of the conflict species to derive effective and long-lasting solutions. Here, we use a long-term study with 106 GPS-collared free-ranging cheetahs (Acinonyx jubatus) to demonstrate how new insights into the socio-spatial organization of this species provide the key for such a solution. GPS-collared territory holders marked and defended communication hubs (CHs) in the core area of their territories. The CHs/territories were distributed in a regular pattern across the landscape such that they were not contiguous with each other but separated by a surrounding matrix. They were kept in this way by successive territory holders, thus maintaining this overdispersed distribution. The CHs were also visited by nonterritorial cheetah males and females for information exchange, thus forming hotspots of cheetah activity and presence. We hypothesized that th...

Sensors

Behavioural studies of elusive wildlife species are challenging but important when they are threa... more Behavioural studies of elusive wildlife species are challenging but important when they are threatened and involved in human-wildlife conflicts. Accelerometers (ACCs) and supervised machine learning algorithms (MLAs) are valuable tools to remotely determine behaviours. Here we used five captive cheetahs in Namibia to test the applicability of ACC data in identifying six behaviours by using six MLAs on data we ground-truthed by direct observations. We included two ensemble learning approaches and a probability threshold to improve prediction accuracy. We used the model to then identify the behaviours in four free-ranging cheetah males. Feeding behaviours identified by the model and matched with corresponding GPS clusters were verified with previously identified kill sites in the field. The MLAs and the two ensemble learning approaches in the captive cheetahs achieved precision (recall) ranging from 80.1% to 100.0% (87.3% to 99.2%) for resting, walking and trotting/running behaviour, ...

Parasites & Vectors

Background Knowledge about parasitic infections is crucial information for animal health, particu... more Background Knowledge about parasitic infections is crucial information for animal health, particularly of free-ranging species that might come into contact with livestock and humans. Methods We investigated the seroprevalence of three tissue-cyst-forming apicomplexan parasites (Toxoplasma gondii, Neospora caninum and Besnoitia besnoiti) in 506 individuals of 12 wildlife species in Namibia using in-house enzyme linked immunosorbent assays (indirect ELISAs applying purified antigens) for screening and immunoblots as confirmatory tests. We included six species of the suborder Feliformia, four species of the suborder Caniformia and two species of the suborder Ruminantia. For the two species for which we had most samples and life-history information, i.e. cheetahs (Acinonyx jubatus, n = 250) and leopards (Panthera pardus, n = 58), we investigated T. gondii seroprevalence in relation to age class, sex, sociality (solitary, mother-offspring group, independent sibling group, coalition group...

Ecosphere

In mammals, male spatial tactics and sociality can be predicted from the size, degree of overlap ... more In mammals, male spatial tactics and sociality can be predicted from the size, degree of overlap and ease of defense of female individual or group home ranges (HRs). An exception is apparently the cheetah (Acinonyx jubatus) for which studies from East Africa describe a socio-spatial organization where resident males defend small territories, which cover a portion of large ranges of solitary females, and nonterritorial males (floaters) roam over vast areas whilst queuing for access to territories. Most studies from southern Africa did not report the existence of territorial males and floaters, but a system with both males and females roaming over vast areas with overlapping HRs. Here, we derive and test predictions from previously described spatial tactics in felids by studying the movements, behavior, and/or physical characteristics of 164 radio-collared Namibian cheetahs on commercial farmland from 2002 to 2014. The results demonstrate the existence of male territory holders and floaters and a, by mammalian standards, unique sociality in that commonly groups of males, sometimes solitary males defended small areas partially overlapping with large ranges of solitary females. When a solitary male or a group of males switched between both tactics, floating usually preceded territory holding, suggesting that both spatial phases are equivalent to distinct life-history stages. Switching from roaming as a floater to holding a territory was also associated with an increase in body mass index (BMI) and a change in the observed behavior of animals captured in traps when approached by humans. Both BMI and this behavior are therefore reliable, quick biomarkers of an individual's space use tactic and life-history stage. We elaborate the implications of this socio-spatial organization for models of ecological movements and on conflict mitigation measures such as translocations or the planning of future protected areas. We suggest that such implications also apply to other species where one sex exhibits two space use tactics and two sets of range sizes.

FEMS Microbiology Ecology

Ecology and evolution, 2018

Population estimates are a fundamental requirement of ecology and conservation. While capture-rec... more Population estimates are a fundamental requirement of ecology and conservation. While capture-recapture models are an established method for producing such estimates, their assumption of homogeneous capture probabilities is problematic given that heterogeneity in individual capture probability is inherent to most species. Such variation must be accounted for by abundance models; otherwise, biased estimates are risked.Here, we investigate the performance of four types of heterogeneity models for estimating abundance of male cheetah , a species with two distinct spatial tactics of territorial and nonterritorial (floater) males. The differences in spatial movements of territory holders and floaters are expected to result in intrasexual heterogeneous capture probabilities. Four heterogeneity models were used to model male abundance at five territories in central Namibia; (a) a spatial tactic model, (b) a finite mixture model, both run in program MARK, (c) a floater-only model, and (d) a...

Cheetahs: Biology and Conservation, 2018

Cheetahs have unique social and mating systems, as well as hunting techniques. Males are either t... more Cheetahs have unique social and mating systems, as well as hunting techniques. Males are either territory holders defending small territories or floaters roaming in large, overlapping, undefended home ranges. Both spatial tactics are adopted by solitary males or coalitions of males. Females are solitary unless accompanied by offspring. They give birth to two to six cubs, which are hidden in a lair for the first 2 months. In ecosystems with other large predator species, cheetahs adopt several predator avoidance behaviors. Nevertheless, cubs can suffer from high mortality by lions and spotted hyenas, and adult cheetahs may lose kills to kleptoparasites. Cheetahs primarily hunt abundant, small to medium sized prey animals using high-speed chases over short distances. They mainly communicate with vocalization and olfaction, often using prominent landmarks for scent marking. Given the increasing human pressure on carnivores, conservation efforts would benefit from behavioral data in human inhabited areas.

Current tracking technology such as GPS data loggers allows biologists to remotely collect large ... more Current tracking technology such as GPS data loggers allows biologists to remotely collect large amounts of movement data for a large variety of species. Extending, and often replacing interpretation based on observation, the analysis of the collected data supports research on animal behaviour, on impact factors such as climate change and human intervention on the globe, as well as on conservation programs. However, this analysis is difficult, due to the nature of the research questions and the complexity of the data sets. It requires both automated analysis, for example, for the detection of behavioural patterns, and human inspection, for example, for interpretation, inclusion of previous knowledge, and for conclusions on future actions and decision making. For this analysis and inspection, the movement data needs to be put into the context of environmental data, which helps to interpret the behaviour. Thus, a major challenge is to design and develop methods and intuitive interface...

Additional file 1: Table S1. Data table of ELISA and IB results containing information on all sam... more Additional file 1: Table S1. Data table of ELISA and IB results containing information on all samples (species, suborder, site, ELISA, IB and final results for T. gondii, N. caninum and B. besnoiti, respectively).

Namibia is thought to host the largest population of free-ranging cheetahs Acinonyx jubatus and t... more Namibia is thought to host the largest population of free-ranging cheetahs Acinonyx jubatus and the majority of this po-pulation inhabits commercial farm-land (Morsbach 1987). Some farmers consider that cheetahs prey on both livestock and wild herbivores that are valuable for trophy hunting, and this perceived offtake has generated conflict leading to the indiscrimina-te elimination of cheetahs from some farms (Marker et al. 1996). To help assess the economic cost of cheetahs on commercial farmland, informati-on on the proportion of different prey species in their diet is required. As it is difficult to directly assess the diet of farmland cheetahs due to their extremely shy behaviour and the small chance of finding fresh prey carcasses (Fig. 1.), we assessed the diet of chee-tahs on Namibian farmland by applying a simple method originally devised for police forensic science. The method is based on the unique imprint of hair from different prey species in cheetah faeces (e.g. Keogh ...

doi: 10.3389/fmicb.2014.00526 Oligotyping reveals differences between gut microbiomes of free-ran... more doi: 10.3389/fmicb.2014.00526 Oligotyping reveals differences between gut microbiomes of free-ranging sympatric Namibian carnivores (Acinonyx

Life history theory predicts that mothers should provide their offspring with a privileged upbrin... more Life history theory predicts that mothers should provide their offspring with a privileged upbringing if this enhances their offspring ’ s and their own fitness. In many mammals, highranking mothers provide their offspring with a privileged upbringing. Whether dispersing sons gain fitness benefits during adulthood from such privileges (a ‘ silver spoon ’ effect) has rarely been examined. In this paper, we show that in the complex, female-dominated society of spotted hyaenas, high-born sons grew at higher rates, were more likely to disperse to clans offering the best fitness prospects, started reproducing earlier and had a higher reproductive value than did lower-born sons. This illustrates the evolutionary importance of maternal effects even in societies in which male size or fighting ability does not influence fitness. By demonstrating for the first time in a non-human mammal that maternal status influences immigration patterns, the study also advances our understanding of two key ...

Proceedings of the 12th International Symposium on Visual Information Communication and Interaction

Recent advances in tracking technology allow biologists to collect large amounts of movement data... more Recent advances in tracking technology allow biologists to collect large amounts of movement data for a variety of species. Analysis of the collected data supports research on animal behaviour, influence of impact factors such as climate change and human intervention, as well as conservation programs. Analysis of the movement data is difficult, due to the nature of the research questions and the complexity of the data sets. It requires both automated analysis, e.g. for the detection of behavioural patterns, and human inspection, e.g. for interpretation, inclusion of previous knowledge, and for conclusions on future actions and decision making. We present a concept and implementation for the visual analysis of cheetah movement data in a web-based fashion that allows usage both in the field and in office environments.

corticosteroid concentrations in Serengeti females were significantly higher than in Ngorongoro f... more corticosteroid concentrations in Serengeti females were significantly higher than in Ngorongoro females. Energy expenditure by lactation is exceptionally high in spotted hyenas and this may be reflected in their corticosteroid levels. The faecal corticosteroid levels in both populations were higher in lactating than in non-lactating females. During periods of social stability, faecal corticosteroid concentrations increased in non-lactating females but not in lactating females as social status declined. Lactating Serengeti females had significantly higher faecal corticosteroid concentrations during periods with acute severe social stress than during periods without, indicating that the HPA axis is sensitive to social stimuli even in lactating females. So far few studies have used non-invasive monitoring methods for assessing social stress in freeranging animals. This study demonstrates for the first time, to the authors' knowledge, that corticosteroid concentrations may differ be...

Namibia is thought to host the largest population of freeranging cheetahs Acinonyx jubatus and th... more Namibia is thought to host the largest population of freeranging cheetahs Acinonyx jubatus and the majority of this population inhabits commercial farmland (Morsbach 1987). Some farmers consider that cheetahs prey on both livestock and wild herbivores that are valuable for trophy hunting, and this perceived offtake has generated conflict leading to the indiscriminate elimination of cheetahs from some farms (Marker et al. 1996). To help assess the economic cost of cheetahs on commercial farmland, information on the proportion of different prey species in their diet is required.

Parasites & Vectors

Background Improved knowledge on vector-borne pathogens in wildlife will help determine their eff... more Background Improved knowledge on vector-borne pathogens in wildlife will help determine their effect on host species at the population and individual level and whether these are affected by anthropogenic factors such as global climate change and landscape changes. Here, samples from brown hyenas (Parahyaena brunnea) from Namibia (BHNA) and spotted hyenas (Crocuta crocuta) from Namibia (SHNA) and Tanzania (SHTZ) were screened for vector-borne pathogens to assess the frequency and genetic diversity of pathogens and the effect of ecological conditions and host taxonomy on this diversity. Methods Tissue samples from BHNA (n = 17), SHNA (n = 19) and SHTZ (n = 25) were analysed by PCRs targeting Anaplasmataceae, Rickettsia spp., piroplasms, specifically Babesia lengau-like piroplasms, Hepatozoidae and filarioids. After sequencing, maximum-likelihood phylogenetic analyses were conducted. Results The relative frequency of Anaplasmataceae was significantly higher in BHNA (82.4%) and SHNA (10...

Noninvasive techniques hold many potential advantages including limiting capture and handling str... more Noninvasive techniques hold many potential advantages including limiting capture and handling stress in wild animals. Scat (feces) samples provide a geophysical landmark and are a biological source for a range of biomedical and ecological questions. The cheetah’s low densities lead to difficulties to study them in the wild, including challenges to find scat samples. Use of professionally trained scat-detection dogs can substantially increase the effectiveness of scat searches. Species, individual identity, and sex of the individual can be determined from scat samples using molecular genetic techniques. Once the information about the individual has been obtained, follow-up questions can be asked. For instance diet composition can be determined using prey species hair found in the scat, and endocrine analyses can provide information about the health and physiology at an individual or population level. Because of their noninvasiveness, these techniques can also be used for long-term mo...

Cheetahs: Biology and Conservation

Considerable research has been conducted on cheetah ecology. Cheetahs can exist in a wide variety... more Considerable research has been conducted on cheetah ecology. Cheetahs can exist in a wide variety of habitats from thick scrub to open grassland, and habitat selection is based on a variety of factors, including visibility, prey density, and avoidance of competitively superior predators. Cheetahs naturally occur at low densities and require a prey base of small to medium-sized ungulates that can be consumed rapidly, minimizing the risks for cheetahs of being detected by larger carnivores that can usurp their kills. Cheetahs exhibit wide ranging movements and large home ranges—over 2000 km 2 in some areas. Reported densities generally range from 0.3 to 3.0 adult cheetahs per 100 km 2 . The species distribution, density, and activity patterns are impacted by human activities and the presence of larger carnivores. Understanding cheetah habitat requirements and movement ecology, especially pertaining to long-distance movements, will become progressively more important as the cheetah’s range becomes increasingly fragmented.

Proceedings of the National Academy of Sciences

Human–wildlife conflicts occur worldwide. Although many nonlethal mitigation solutions are availa... more Human–wildlife conflicts occur worldwide. Although many nonlethal mitigation solutions are available, they rarely use the behavioral ecology of the conflict species to derive effective and long-lasting solutions. Here, we use a long-term study with 106 GPS-collared free-ranging cheetahs (Acinonyx jubatus) to demonstrate how new insights into the socio-spatial organization of this species provide the key for such a solution. GPS-collared territory holders marked and defended communication hubs (CHs) in the core area of their territories. The CHs/territories were distributed in a regular pattern across the landscape such that they were not contiguous with each other but separated by a surrounding matrix. They were kept in this way by successive territory holders, thus maintaining this overdispersed distribution. The CHs were also visited by nonterritorial cheetah males and females for information exchange, thus forming hotspots of cheetah activity and presence. We hypothesized that th...

Sensors

Behavioural studies of elusive wildlife species are challenging but important when they are threa... more Behavioural studies of elusive wildlife species are challenging but important when they are threatened and involved in human-wildlife conflicts. Accelerometers (ACCs) and supervised machine learning algorithms (MLAs) are valuable tools to remotely determine behaviours. Here we used five captive cheetahs in Namibia to test the applicability of ACC data in identifying six behaviours by using six MLAs on data we ground-truthed by direct observations. We included two ensemble learning approaches and a probability threshold to improve prediction accuracy. We used the model to then identify the behaviours in four free-ranging cheetah males. Feeding behaviours identified by the model and matched with corresponding GPS clusters were verified with previously identified kill sites in the field. The MLAs and the two ensemble learning approaches in the captive cheetahs achieved precision (recall) ranging from 80.1% to 100.0% (87.3% to 99.2%) for resting, walking and trotting/running behaviour, ...

Parasites & Vectors

Background Knowledge about parasitic infections is crucial information for animal health, particu... more Background Knowledge about parasitic infections is crucial information for animal health, particularly of free-ranging species that might come into contact with livestock and humans. Methods We investigated the seroprevalence of three tissue-cyst-forming apicomplexan parasites (Toxoplasma gondii, Neospora caninum and Besnoitia besnoiti) in 506 individuals of 12 wildlife species in Namibia using in-house enzyme linked immunosorbent assays (indirect ELISAs applying purified antigens) for screening and immunoblots as confirmatory tests. We included six species of the suborder Feliformia, four species of the suborder Caniformia and two species of the suborder Ruminantia. For the two species for which we had most samples and life-history information, i.e. cheetahs (Acinonyx jubatus, n = 250) and leopards (Panthera pardus, n = 58), we investigated T. gondii seroprevalence in relation to age class, sex, sociality (solitary, mother-offspring group, independent sibling group, coalition group...

Ecosphere

In mammals, male spatial tactics and sociality can be predicted from the size, degree of overlap ... more In mammals, male spatial tactics and sociality can be predicted from the size, degree of overlap and ease of defense of female individual or group home ranges (HRs). An exception is apparently the cheetah (Acinonyx jubatus) for which studies from East Africa describe a socio-spatial organization where resident males defend small territories, which cover a portion of large ranges of solitary females, and nonterritorial males (floaters) roam over vast areas whilst queuing for access to territories. Most studies from southern Africa did not report the existence of territorial males and floaters, but a system with both males and females roaming over vast areas with overlapping HRs. Here, we derive and test predictions from previously described spatial tactics in felids by studying the movements, behavior, and/or physical characteristics of 164 radio-collared Namibian cheetahs on commercial farmland from 2002 to 2014. The results demonstrate the existence of male territory holders and floaters and a, by mammalian standards, unique sociality in that commonly groups of males, sometimes solitary males defended small areas partially overlapping with large ranges of solitary females. When a solitary male or a group of males switched between both tactics, floating usually preceded territory holding, suggesting that both spatial phases are equivalent to distinct life-history stages. Switching from roaming as a floater to holding a territory was also associated with an increase in body mass index (BMI) and a change in the observed behavior of animals captured in traps when approached by humans. Both BMI and this behavior are therefore reliable, quick biomarkers of an individual's space use tactic and life-history stage. We elaborate the implications of this socio-spatial organization for models of ecological movements and on conflict mitigation measures such as translocations or the planning of future protected areas. We suggest that such implications also apply to other species where one sex exhibits two space use tactics and two sets of range sizes.

FEMS Microbiology Ecology

Ecology and evolution, 2018

Population estimates are a fundamental requirement of ecology and conservation. While capture-rec... more Population estimates are a fundamental requirement of ecology and conservation. While capture-recapture models are an established method for producing such estimates, their assumption of homogeneous capture probabilities is problematic given that heterogeneity in individual capture probability is inherent to most species. Such variation must be accounted for by abundance models; otherwise, biased estimates are risked.Here, we investigate the performance of four types of heterogeneity models for estimating abundance of male cheetah , a species with two distinct spatial tactics of territorial and nonterritorial (floater) males. The differences in spatial movements of territory holders and floaters are expected to result in intrasexual heterogeneous capture probabilities. Four heterogeneity models were used to model male abundance at five territories in central Namibia; (a) a spatial tactic model, (b) a finite mixture model, both run in program MARK, (c) a floater-only model, and (d) a...