How lions move at night when they hunt?

Animals must often balance food availability and predation risk when selecting habitat. Here, we examined habitat preferences of large mammalian herbivores in a long‐term fire experiment in the Kruger National Park, South Africa to assess the role of bottom‐up (e.g., forage quantity/quality) and top‐down (e.g., predation risk) processes in driving herbivore distributions. We focused on experimental plots (∼10 ha on average) that have been burned in the winter (August) since 1954 at 1‐ and 3‐yr intervals, or left unburned (n = 3 per burn type). Herbivore distributions (during both day and night) and plant community structure were surveyed on each plot during the growing seasons (November–March) of 2005–2006, 2006–2007, and 2007–2008. Overall, we sighted 4,187 individuals representing twelve species of mammalian herbivores. Impala (Aepyceros melampus), zebra (Equus quagga), and wildebeest (Connochaetes taurinus) comprised 37%, 28%, and 18% of all individuals observed, respectively. Several species such as African buffalo (Syncerus caffer), wildebeest, and giraffe (Giraffa camelopardalis) exhibited a significant trade‐off between food acquisition and minimizing predation risk by foraging in areas with lower density of woody vegetation. We also observed significant day vs. night dynamics in herbivore habitat selection. For example, zebra utilized annual or triennial burns during the day depending on which years the plots were burned, but they avoided triennial burns with dense woody vegetation in favor of more open annual burns at night when predators such as lions (Panthera leo) are more active. Similarly, the smaller, mixed‐feeding impala appeared to use riskier habitats with more diverse forage options during the day (triennial burns and unburned plots) but used less risky habitats at night (annual and triennial burns). Diurnal vs. nocturnal patterns are often overlooked in studies of habitat selection but are necessary for understanding the factors that shape distribution. The variation we observed in herbivore distribution patterns during this three‐year period indicates that different species exhibit different trade‐offs with respect to food and predation risk. Factors such as body size, nutritional requirements, prey escape tactics, and recent fire history likely mediated these interspecific differences.

Conservation conundrum: Endangered predators eating endangered prey

Environmental factors are common forces driving infectious disease dynamics. We compared interannual and seasonal patterns of anthrax infections in two multihost systems in southern Africa: Etosha National Park, Namibia, and Kruger National Park, South Africa. Using several decades of mortality data from each system, we assessed possible transmission mechanisms behind anthrax dynamics, examining (1) within‐ and between‐species temporal case correlations and (2) associations between anthrax mortalities and environmental factors, specifically rainfall and the Normalized Difference Vegetation Index (NDVI), with empirical dynamic modeling. Anthrax cases in Kruger had wide interannual variation in case numbers, and large outbreaks seemed to follow a roughly decadal cycle. In contrast, outbreaks in Etosha were smaller in magnitude and occurred annually. In Etosha, the host species commonly affected remained consistent over several decades, although plains zebra (Equus quagga) became relatively more dominant. In Kruger, turnover of the main host species occurred after the 1990s, where the previously dominant host species, greater kudu (Tragelaphus strepsiceros), was replaced by impala (Aepyceros melampus). In both parks, anthrax infections showed two seasonal peaks, with each species having only one peak in a year. Zebra, springbok (Antidorcas marsupialis), wildebeest (Connochaetes taurinus), and impala cases peaked in wet seasons, while elephant (Loxodonta africana), kudu, and buffalo (Syncerus caffer) cases peaked in dry seasons. For common host species shared between the two parks, anthrax mortalities peaked in the same season in both systems. Among host species with cases peaking in the same season, anthrax mortalities were mostly synchronized, which implies similar transmission mechanisms or shared sources of exposure. Between seasons, outbreaks in one species may contribute to more cases in another species in the following season. Higher vegetation greenness was associated with more zebra and springbok anthrax mortalities in Etosha but fewer elephant cases in Kruger. These results suggest that host behavioral responses to changing environmental conditions may affect anthrax transmission risk, with differences in transmission mechanisms leading to multihost biseasonal outbreaks. This study reveals the dynamics and potential environmental drivers of anthrax in two savanna systems, providing a better understanding of factors driving biseasonal dynamics and outbreak variation among locations.

Hunting by male lions: ecological influences and socioecological implications

Background: Although the rate of emerging infectious diseases that originate in wildlife has been increasing globally in recent decades, there is currently a lack of epidemiological data from wild animals.Methodology: We used serology to determine prior exposure to foot‐and‐mouth disease virus (FMDV), Brucella spp., and Coxiella burnetii and used genetic testing to detect blood‐borne parasitic infections in the genera Ehrlichia, Anaplasma, Theileria, and Babesia from wildlife in two national parks, Kruger National Park (KNP), South Africa, and Etosha National Park (ENP), Namibia. Serum and whole blood samples were obtained from free‐roaming plains zebra (Equus quagga), greater kudu (Tragelaphus strepsiceros), impala (Aepyceros melampus), and blue wildebeest (Connochaetes taurinus). Risk factors (host species, sex, and sampling park) for infection with each pathogen were assessed, as well as the prevalence and distribution of co‐occurring infections.Results: In KNP 13/29 (45%; confidence interval [CI]: 26%–64%) kudus tested positive for FMD, but none of these reacted to SAT serotypes. For brucellosis, seropositive results were obtained for 3/29 (10%; CI: 2%–27%) kudu samples. Antibodies against C. burnetii were detected in 6/29 (21%; CI: 8%–40%) kudus, 14/21 (67%; CI: 43%–85%) impalas, and 18/39 (46%; CI: 30%–63%) zebras. A total of 28/28 kudus tested positive for Theileria spp. (100%; CI: 88%–100%) and 27/28 for Anaplasma/Ehrlichia spp. (96%; CI: 82%–100%), whereas 12/19 impalas (63%) and 2/39 zebra (5%) tested positive for Anaplasma centrale. In ENP, only 1/29 (3%; CI: 0%–18%) wildebeest samples tested positive for FMD. None of the samples tested positive for brucellosis, while C. burnetii antibodies were detected in 26/30 wildebeests (87%; CI: 69%–96%), 16/40 kudus (40%; CI: 25%–57%), and 26/26 plains zebras (100%; CI: 87%–100%). A total of 60% Anaplasma/Ehrlichia spp. and 35% Theileria/Babesia spp. in kudu and 37% wildebeest tested positive to Theileria sp. (sable), 30% to Babesia occultans, and 3%–7% to Anaplasma spp. The seroprevalence of Q fever was significantly higher in ENP, while Brucella spp., Anaplasma, Ehrlichia, Theileria, and Babesia species were significantly higher in KNP. Significant coinfections were also identified.Conclusion: This work provided baseline serological and molecular data on 40+ pathogens in four wildlife species from two national parks in southern Africa.

The objective of this study was to assess the host status of African buffaloes, Syncerus caffer, for the one-host tick Rhipicephalus (Boophilus) decoloratus. To this end the R. (B.) decoloratus burdens of ten buffaloes examined in three north-eastern KwaZulu-Natal Province (KZN) nature reserves were compared with those of medium-sized to large antelope species in these reserves and in the southern Kruger National Park (KNP), Mpumalanga Province. The R. (B.) decoloratus burdens of the buffaloes were considerably smaller than those of the antelopes in the KNP, but not those in the KZN reserves. The life-stage structure of the R. (B.) decoloratus populations on the buffaloes, in which larvae predominated, was closer to that of this tick on blue wildebeest, Connochaetes taurinus, a tick-resistant animal, than to that on other antelopes. A single buffalo examined in the KNP was not infested with R. (B.) decoloratus, whereas a giraffe, Giraffa camelopardalis, examined at the same locality and time, harboured a small number of ticks. In a nature reserve in Mpumalanga Province adjacent to the KNP, two immobilized buffaloes, from which only adult ticks were collected, were not infested with R. (B.) decoloratus, whereas greater kudus, Tragelaphus strepsiceros, examined during the same time of year in the KNP harboured large numbers of adult ticks of this species. African buffaloes would thus appear to be resistant to infestation with R. (B.) decoloratus, and this resistance is expressed as the prevention of the majority of tick larvae from developing to nymphs.

To decide where and when to move, animals combine memorised information with environmental cues. Wind speed and direction can affect the way animals perceive the environment by reducing the detection and shaping the spatial distribution of sensory cues. Although these cues are expected to be used for forage localisation and predation avoidance in large herbivores, for instance, we still do not know to what extent wind can ultimately influence their large-scale movement decisions. To tackle this knowledge gap, we used GPS data from four species of large African herbivores experiencing contrasted predation risks (blue wildebeest, Connochaetes taurinus, plain zebras, Equus quagga, African buffalo, Syncerus caffer, African elephant, Loxodonta africana), in multiple protected areas. We first investigated whether individuals reduce predation risk by avoiding long-distance movements under windy conditions. We then analysed whether they favour moving upwind to maximise their information gain as they travel. We found no clear decrease in the largest step length as wind speed increases and suggest that local habitat could buffer the strength of wind speed (i.e. topography or vegetation). We, however, found that large herbivores tend to move upwind rather than cross- or downwind, although the effect was generally small. We point out that individuals might be more constrained in their use of cues carried by the wind than initially thought, due to the existence of dominant wind directions at all sites. Altogether, our study suggests that wind has little general, consistent, effects on large herbivore movement decisions. Some sites or species-specific results, however, call for delving deeper into the context-specificity of wind effects.

Cloning, sequencing and expression of white rhinoceros ( Ceratotherium simum) interferon-gamma (IFN-γ) and the production of rhinoceros IFN-γ specific antibodies

Predation risk from lions (Panthera leo) has been linked to habitat characteristics and availability and traits of prey. We separated the effects of vegetation density and the presence of drinking water by analyzing locations of lion kills in relation to rivers with dense vegetation, which offer good lion stalking opportunities, and artificial water points with low vegetation density. The spatial distribution of lion kills was studied at the Klaserie Private Nature Reserve, South Africa. The distance between 215 lion kills and the nearest water source was analyzed using generalized linear models. Lions selected medium-sized prey species. Lion kills were closer to rivers and to artificial water points than expected by random distribution of the kills. Water that attracted prey, and not the vegetation density in riverine areas, increased predation risk, with kills of buffalo (Syncerus caffer), kudu (Tragelaphus strepsiceros), and wildebeest (Connochaetes taurinus) as water-dependent prey species. Traits of prey species, including feeding type (food habits), digestion type (ruminant or nonruminant); or body size, did not explain locations of lion kills, and no seasonal patterns in lion kills were apparent. We argue that the cascading impact of lions on local mammal assemblages is spatially heterogeneous.

Bovine tuberculosis (TB), caused by Mycobacterium bovis, has become established in Kruger National Park, South Africa, in the cape buffalo (Syncerus caffer) population and in other species. TB in prey species has resulted in infection and morbidity in the resident lion (Panthera leo) prides. The only validated live animal test currently available for lions is the intradermal tuberculin test. Because this test requires capture twice, 72 hr apart, of free-ranging lions to read results, it is logistically difficult to administer in a large ecosystem. Therefore, development of a rapid animal-side screening assay would be ideal in providing information for wildlife managers, veterinarians, and researchers working with free-living lion prides. This study reports preliminary descriptive results from an ongoing project evaluating two serologic tests for M. bovis (ElephantTB Stat-Pak and dual path platform VetTB). Disease status was determined by postmortem culture and presence of pathologic lesions in 14 free-ranging lions. Seropositivity was found to be associated with M. bovis infection. Extended field studies are underway to validate these rapid animal-side immunoassays for antemortem screening tests for TB in lions.

Anthrax has been studied intensively in Etosha National Park, Namibia since 1966; in addition, since 1975, mortality due to rabies and all other causes has been recorded, totalling 6,190 deaths. Standard diagnostic procedures demonstrated that at least 811 deaths (13%) were due to anthrax and 115 deaths (2%) were caused by rabies. Of the total number of deaths due to anthrax, 97% occurred in zebra (Equus burchelli), elephant (Loxodonta africana), wildebeest (Connochaetes taurinus) and springbok (Antidorcas marsupialis) while 96% of rabies deaths occurred in kudu (Tragelaphus strepsiceros), jackal (Canis mesomelas), bat-eared fox (Otocyon megalotis) and lion (Panthera leo). Anthrax deaths were highest in the rainy season for zebra, wildebeest and springbok, while elephant mortality peaked during dry seasons. No statistical relationship existed between seasonal rainfall and overall incidence of either anthrax or rabies. Control of anthrax is limited to prophylactic inoculation when rare or endangered species are threatened. Incineration of anthrax carcasses and chemical disinfection of drinking water are not feasible at Etosha. Rabies control consists of the destruction of rabid animals and incineration of their carcasses when possible.

There is a lack of consensus among conservationists regarding the association between trophy hunting and wildlife poaching. Anti-hunting groups argue that trophy hunting is against animal welfare and contributes to wildlife population decline so it must be refuted. On the other hand, pro-hunting groups for advocate regulated hunting as an essential tool for supporting habitat protection and reducing crimes. Regulated hunting creates incentives for conservation through direct and indirect methods and reduces wildlife poaching in areas where ecotourism cannot be practically viable. We used fifteen years' trophy hunting and poaching of African elephant (Loxodonta africana), lion (Panthera leo), Cape buffalo (Syncerus caffer), Common Zebra (Equus quagga), hippopotamus (Common Hippotamus amphibious) and Greater kudu (Tragelaphus strepsiceros) from Selous and Rungwa game reserves in Tanzania. The results showed that there is no evidence of influence of regulated hunting on poaching rate for all species with exception of African elephant. Poaching rate of African elephant was found to be higher than the rate of regulated hunting because of limited number of quota set by Convention on International Trade in Endangered Species (CITES) and international restriction of elephant hunting imposed by the International Union for Conservation of Nature (IUCN). The study suggests that the contentions to stop trophy hunting because of an increase in poaching incidents have no empirical justification. Thus, more effort should be on anti-poaching activities ensuring the adherence to legal hunting regulations. Key words: Poaching, hunting, trophy, conservation, biodiversity.

Illegal hunting of wildlife is a major issue in today's society, particularly in tropical ecosystems. In this study, a total of 114 local residents from eight villages located in four wards adjacent to the northern Gonarezhou National Park, south-eastern Zimbabwe were interviewed in 2009, using semi-structured questionnaires. The study aimed to answer the following questions: (i) what is the prevalence of illegal hunting and what are commonly used hunting methods? (ii) Which wild animal species are commonly hunted illegally? (iii) What are the main reasons for illegal hunting? (iv) What strategies or mechanisms are currently in place to minimize illegal hunting? Overall, 59% of the respondents reported that they saw bushmeat, meat derived from wild animals, and/or wild animal products being sold at least once every six months, whereas 41% of the respondents reported that they had never seen bushmeat and/or wild animal products being sold in their villages and/or wards. About 18% of the respondents perceived that illegal hunting had increased between 2000 and 2008, whereas 62% of the respondents perceived that illegal hunting had declined, and 20% perceived that it remained the same. Snaring (79%) and hunting with dogs (53%) were reportedly the most common hunting methods. A total of 24 wild animal species were reportedly hunted, with African buffalo ( Syncerus caffer) (18%), Burchell's zebra ( Equus quagga) (21%), kudu ( Tragelaphus strepsiceros) (25%) and impala ( Aepyceros melampus) (27%) amongst the most targeted and preferred animal species. In addition, large carnivores, including spotted hyena ( Crocuta crocuta) (11%), leopard ( Panthera pardus) (10%) and African lion ( Panthera leo) (8%), were reportedly hunted illegally. The need for bushmeat, for household consumption (68%), and raising money through selling of wild animal products (55%) were reported as being the main reasons for illegal hunting. Strengthening law enforcement, increasing awareness and environmental education, and developing mechanisms to reduce human-wildlife conflicts will assist in further minimizing illegal hunting activities in the Gonarezhou ecosystem.

Trypomastogotes of Trypanosoma brucei were detected from 4 asymptomatic kudus (Tragelaphus strepsiceros) on a game ranch located approximately 45 km north east of Lusaka, Zambia. Blood smears examined from 14 wildlife species comprising of the impala (Aepyceros melampus), Kafue lechwe (kobus leche kafuensis), sable antelope (Hippotragus niger), tsessebe (Damaliscus lunatus), warthog (Phacochoerus aethiopicus), puku (Kobus vardoni), zebra (Equus burchelli), waterbuck (Kobus ellipsiprymnus), bushbuck (Tragelaphus scriptus), reedbuck (Redunca arundinum), wilderbeest (Connochaetes taurinus), hartebeest (Alcephelus lichtensteini), African buffalo (Syncerus caffer), and kudu (Tragelaphus strepsiceros) showed that only the kudu had T. brucei. Although game ranching has emerged to be a successful ex-situ conservation strategy aimed at saving the declining wildlife population in the National Parks, our findings suggest that it has the potential of aiding the re-distribution of animal diseases. Hence, there is a need for augmenting wildlife conservation with disease control strategies aimed at reducing the risk of disease transmission between wildlife and domestic animals.

Genotype by environment interactions on culling rates and 305-day milk yield of Holstein cows in 3 US regions