The influence of free-ranging dogs on the native wildlife
populations in the Mara North Conservancy, Masai Mara
The influence of free-ranging dogs on the native wildlife populations in the Mara North Conservancy, Masai Mara
Nicolai Elmo Jensen 20073297
Master’s Thesis
Department of Bioscience Genetics, Ecology and Evolution
Aarhus University
October 2014
Supervisors Trine Bilde
External, Jesper Stagegaard
Preface
My Master’s Thesis is the very first step in a long-term dog management project in the Mara North Conservancy. It is meant to support the conservation and management strategies, as well as a baseline for future research projects in the area of the Mara North Conservancy.
My present Master’s Thesis is divided into three sections. Part I is an overview section that gives a general background of the overall topic and the potential deleterious effects that dogs might pose to native wildlife species and populations. Part II is my empirical field study, presented as a scientific paper. In part III, I will, based on the overview, existing literature and my field study, suggest solutions and management tools for the future management and conservation of the Mara North Conservancy. Finally I will recommend important and relevant topics for future research, that in my point of view can increase our understanding of the impacts of dogs in wildlife habitats, and contribute to the future existence of this spectacular wilderness.
PART I – Masai Mara and human settlement
The cohesive ecosystem of Masai Mara and Serengeti in the southern Kenya and northern part of Tanzania is one of the world most spectacular places on earth, with regard to wildlife abundance and biodiversity. Masai Mara is known as one of the best wildlife reserves in Africa and it is world famous for its abundance of large carnivores and the annual “great migration” where more than 1,5 million wildebeests arrives from Serengeti in their search for fresh pasture.
Despite this amazing scenery, less than half of the Masai Mara is under official protection, and is yet under an increasing pressure from the surroundings. Not surprisingly, the threat is from human activities, including agriculture, mining of natural resources, poaching etc. The biggest threat is the increasing human settlement in the area, with all its inevitable challenges it causes.
Implementing of conservancies is a new conservation discipline in Kenya, to protect and ensure the natural wildlife habitat. To minimize some of the many negative effects caused by human activity, conservancies are made as a buffer zone between the protected wildlife reserves and settlement areas. Conservancies are not funded by the government but are private partnerships between the private tourism sector (tourist camps) and the local community. The land is typically leased, to set aside land purely for the purpose of wildlife conservation. The local Masais are semi-normadic pastoralists and their cattle are at the centre of their culture and social life. Communities living in natural wildlife areas must be provided with the economic incentives to set aside their land for wildlife conservation. Without a partnership between Masai landowners and the private tourism sector it would be difficult to ensure sustainable, well-coordinated and effective wildlife
conservation and management along with recognizable benefits for all stakeholders.
Dogs in the Masai culture are used for guarding and protecting livestock from wild predators and thereby reducing the human-wildlife conflicts, that are inevitable in areas where humans and wildlife coexists. However dogs have been proven to have deleterious effects on wildlife with regard to pathogen transmission, predation, disturbance etc. (Brickner, 2003, Roelke-Parker et al., 1996, Barnett, 1986). The possible impact of dogs has never been investigated in the Mara North Conservancy, and to improve the future conservation and management of the area, knowledge is fundamental, to clarify and mitigate some of the potential risks, dogs pose to the wildlife. Such knowledge may be essential for the future management plans and conservation of this unique area of Masai Mara.
Dogs
Dogs (Canis familiaris) have accompanied man all over the world since their domestication 15.000 years ago (Savolainen et al., 2002) and today, domestic dogs are the most abundant mammalian carnivore in the world, with a global population estimated to 700 millions (Hughes, J., Macdonald, D. W. 2012). Dogs have diverse and complex roles in human communities such as pets, family members, working animals, guarding property and livestock, performing search and rescue missions, assisting disabled people etc. (Serpell 1995). Dogs are often defined from their level of dependency to humans, and several efforts have been made to categorize them. It is generally accepted that dogs can be subdivided in six groups, which are overlapping (Nesbitt, 1975; Daniels
& Bekoff, 1989; Green & Gipson, 1994; Boitani et al., 1995; MacDonald & Carr, 1995).
1. Owned dogs: dogs that are owned and restricted in movement to a proscribed outdoor or indoor area. Although the potential for these dogs to interact with wildlife is limited, they can nonetheless have an effect on wildlife when they accompany humans into natural areas or if their unvaccinated status enhances the disease reservoir status of the broader dog population (Fiorello et al., 2006;
Banks & Bryant, 2007; Koster, 2008; Lenth, Knight & Brennan, 2008).
2. Urban free-ranging dogs: dogs that are not owned by humans but are commensals, subsisting on garbage and other human derived material as their primary food source. They usually do not come
into contact with wildlife, except in urban parks (Banks & Bryant, 2007; Lenth et al., 2008).
3. Rural free-ranging dogs: dogs that are owned or peripherally associated with human habitations but are not confined to a proscribed out-door area. These include (but are not limited to) ‘stray’
dogs and owned farm and pastoral companion dogs, whose daily activity pattern may involve ranging that can bring them into contact with wildlife, especially when human habitations border
wildlife reserves or other natural areas (Butler et al., 2004; Vanak, 2008).
4. Village dogs: unconfined dogs that are associated with human habitations in rural environments
but rarely leave the immediate vicinity of the village (MacDonald & Carr, 1995; Vanak, 2008).
5. Feral dogs: dogs that are completely wild and independent of human-derived material as food
sources (Nesbitt, 1975; Green & Gipson, 1994).
6. Wild dogs: dingoes, feral dogs and their hybrids in Southeast Asia and Australasia that have a history of independence from humans and are no longer considered domesticated (Corbett, 1995;
Sillero-Zubiri, Hoffmann & Macdonald, 2004).
In rural areas of Africa, as well as other parts of the world where pastoralism and livestock farming are fundamental for livelihood, dogs are kept for guarding livestock. In Masai Mara in Kenya, dogs are used for guarding and protecting livestock at night against wild carnivores such as spotted hyenas (Crocuta crocuta), leopards (Panthera pardus) and lions (Panthera leo). As the human population increases, so does the population of dogs, and without proper care, handling and management, they might become a nuisance and cause serious challenges and potential harm to their surrounding environment.
Dogs as pathogen vectors
In pastoral areas, areas next to nature reserves and protected land, free-ranging dogs may interact with wildlife at multiple levels, including as predators, prey, competitors, and as reservoirs and vectors for pathogens (Butler, du Toit & Bingham 2004). Direct predation of wildlife is probably the most obvious interaction to observe, however more complex and subtle interactions, such as transmission of pathogens has received much more attention. Transmission of rabies, canine
distemper virus (CDV), canine parvovirus (CPV) and sarcoptic mange, have all been documented to have severe impacts on wildlife populations. Rabies and CDV are by far the most investigated, and have had dramatic impacts in wild populations. An outbreak of rabies in Masai Mara in 1989 was partly responsible for the nearly extinction of the African wild dog (Lycaon pictus) (Pain, 1997, Woodroffe, 1999). Additionally the highly endangered Ethiopian wolf (Canis simensis) has also suffered from a number of rabies epidemics spread from dogs, and the population is now reduced by more than 70% (Randall et al., 2006). In 1994, a CDV epidemic killed 30% of the lion
(Panthera leo) population in the Serengeti National Park (Brickner, 2003, Roelke-Parker et al., 1996). CPV have been associated with mortality of African wild dog pubs (Creel et al., 1997;
Woodroffe, 1997). Sarcoptic mange has been affecting cheetahs (Acinonyx jubatus), Thomson’s gazelles (Eudorcas thomsonii), wildebeests, (Connochaetes taurinus) (Gakuya et al., 2012) and might as well affect many other species (Cleaveland et al., 2007). The transmission of pathogens can either be direct through physical interaction with an infected individual, indirect through the environment, or through an intermediate host. The pathogens (viruses and intestinal parasites) have different modes of transmission. Direct interaction is necessary in the transmission of rabies and CDV, as it involves oronasal exposure to aerosolized respiratory secretions or bite wounds exposure to saliva. CPV is transmitted via ingestion or inhalation of infected fecal materials. The mite
Sarcoptes scabiei that cause sarcoptic mange can be spread both via direct and indirect interaction (Gakuya, 2011; Arlian, 1989).
Dogs as predators
Dogs are generalist and opportunistic predators, with a highly variable diet ranging from human faeces, garbage, berries, birds, reptiles to medium size wild animals like young zebras and
wildebeests. In environments where predator guilds are largely intact and relatively diverse (e.g. in Africa and North America), dogs often assume the roles of smaller-bodied and subordinate
mesopredators, due to the presence of larger predators (Butler et al. 2004; Ritchie and Johnson, 2009). Dogs are potentially effective predators and are capable of killing significant numbers of different species, across a range of taxa and body sizes (Vanak et al. 2010; Young et al. 2011).
Dogs as predators have severe impact on endemic wildlife species, e.g. in Galapagos, where dogs are predators of land- and marine iguanas (Conolophus subcristatus and Amblyrhynchus cristatus) (Barnett, 1986; Kruuk, 1979; Kruuk and Snell, 1981), and in Chile and Argentina (Silva-Rodríuez E. A. and Sieving K. E. 2011), where free-ranging dogs predate on pudu (Pudu puda). In India dogs are preying on blackbuck (Antelope cervicapra) (Jhala and Giles, 1991; Jhala, 1993), in New
Zealand, a single free ranging dog killed about 500 Kiwis (Apteryx australis) in a population of 900 birds in a few months (Taborsky, 1988), and in Ethiopia they compete with the highly endangered Ethiopian wolf (Canis simensis) for rodents (Gottelli and Sillero-Zubiri, 1992; Sillero-Zubiri and Gottelli, 1994; Sillero-Zubiri and Gottelli, 1995). Most studies on impact of dogs, have been focusing on mammals, but as described above dogs have a very wide range of diet and prey upon birds, amphibians and reptiles (Campos et al. 2007) which are very likely be affected as well. Many ground living birds can potentially experience reduced reproductive success, caused by the presence of high density of dogs. In the Las Amoladeras Bird Reserve in Spain, 68-99% of lark- (Galerida theklae and Calandrella rufescend) nests were depredated, by red fox and feral dogs (Yanes and Suarez, 1996). The extend of predation pressure by dogs varies considerably across studies. In some cases the predation pressure is high (Sludskii, 1962), where approximately 10.000 saiga antelopes (Saiga tatarica) were reported killed annually in Kazakhstan, where as in other cases no obvious evidence of predations is found, or it is not possible to verify if dogs is the primary predator or scavengers (Bergeron and Pierre, 1981).
Dogs as agents of disturbance
The response of wildlife to the presence of a threatening stimulus, such as a dog, is referred to as disturbance (Hockin et al., 1992.). Free-ranging dogs’ behavior tend to be both diurnal and
nocturnal, and dogs show large variation in their home range sizes (1- 2500 ha), which potentially may have great disturbance effects on wildlife (Meek, 1999). The presence of a dog in an
environment can affect wildlife in very deleterious ways (subtle, sub-lethal, lethal) (Preisser et al., 2005; Zanette et al., 2011.). Canids may instinctively hunt wildlife and therefore the dogs’ presence is perceived as a threat by wildlife (Gabrielsen and Smith, 1995). Among the diverse array of anthropomorphic stimuli encountered by wildlife (e.g. human activity, presence of livestock and predators), dogs are associated with a specific set of responses. The most common anti-predator behavior is vigilance, flight, retreat to refuge, freezing behavior and hiding. Behavioral changes in the presence of a threatening stimulus have been widely documented (e.g. Hockin et al., 1992) and often involve ceasing normal activities (e.g. foraging, parental care, resting, display). A growing amount of literature also points to physiological changes and stress response, such as hormone release and altered heart rates (MacArthur et al., 1982). Very little is known about the impact of disturbance caused by free- ranging dogs on wildlife populations, although an expanding literature examines the interaction between wildlife and “pet” dogs accompanied by people. Gill et al. 1996 has shown population effects of disturbance, because disturbance lowers habitat quality and thus reduces carrying capacity. Mountain gazelles (Gazella gazella) in Israel have been proved to form larger group sizes to gain protection in areas with presence of feral dogs, which preyed on juveniles.
Culling of these feral dogs significantly increased the kid:female ratio in subsequent years among the Mountain gazelles (Manor and Saltz, 2004). Unlike birds that can fly away when disturbed, larger mammals often escape over long distances and are more likely to be displaced from their home range and become stressed physiologically, and thereby experiencing the negative effects of escape for longer durations (Gompper, 2014). It is primarily the effect on mammals that has been
investigated, however birds, reptiles, and amphibians may also be negatively affected by the disturbance of free-ranging dogs.
Dogs as competitors
Until recently, very scarce knowledge about the role of dogs as competitors existed. Studies across the world have lately highlighted several key aspects of the role of the competitive dynamics that occur between dogs and sympatric carnivores (e.g. Butler and Bingham 2000). Studies such as Butler and du Toit (2002), have demonstrated that dogs often compete with native carnivores for food, and that smaller carnivores may react to dogs as they would do to any other mid-sized predator, with vigilance, lowered food intake or avoidance of dog-dominated habitats. The
competitive ability of dogs is likely to be influenced by their population size and ranging behaviour (Vanak and Gompper 2009). The larger the population of dogs, and the wider ranging behaviour, the more likely they are to either directly or indirectly affect other carnivore species.
Due to the highly efficient scavenging behaviour of dogs, the potential for competing with mammalian- and avian scavengers such as, black-backed jackals (Canis mesomelas) and vultures (Gyps africanus, Torgos tracheliotus, Trigonoceps occipitalis, Necrosyrtes monachus) seems to be of great concern. Factors such as, physical dominance, high density, nocturnal and diurnal foraging ability and greater tolerance to human disturbance, allow dogs to dominate carcasses, especially at the periphery of human settlements (Gompper, 2014; du Toit, 2002). Jackals and dogs have very similar opportunistic feeding habits (Skinner and Chimimba, 2005) and their home ranges and diet may overlap. Carcass experiments in Zimbabwe showed that side-striped jackals (Canis adustus) were attracted to experimental carrions but did not feed, perhaps because they would avoid the scavenging dogs present (Butler and du Toit, 2002). Additionally they found that dogs were the most efficient scavengers, consuming up to 60% of the total carcass biomass, where vultures were second most efficient with a consumption of 15% of the biomass. These patterns suggest that dogs primarily compete with vultures and maybe already have displaced jackals (C. mesomelas, C.
aureus and C. adustus) from certain areas.
PART II
The influence of free-ranging dogs on the native wildlife populations in the Mara North Conservancy, Masai Mara
Abstract
Increasing abundance of free-ranging domestic dogs (Canis familiaris) along boundaries of
protected wildlife reserves is of growing concern to conservationists in the rural areas of Kenya, as well as the rest of the world. Several studies (e.g. Cleaveland 2000; Brickner, 2003; Butler, du Toit
& Bingham 2004 and Kruuk and Snell 1981) have shown that dogs have multiple negative impacts on native wildlife populations, including being vectors and reservoirs of numerous of transmittable pathogens, predators, and competitors. This study has examined some of the potential threats free- ranging dogs pose to the native wildlife in the Mara North Conservancy, along the northeastern border of Masai Mara National Reserve. In the present study, the current dog population within the conservancy was estimated to c. 2500 dogs, where the majority is owned by settlers, though free- roaming. Of 28 dogs sampled, 25% and 67,8% were tested positive for antibodies against canine distemper virus and canine parvovirus, respectively. Intestinal parasites were found in 3 out of 31 samples. Prevalence for sarcoptic mange was not detected. In transect observation studies, no significant effect of the number of dogs on the abundance of wildlife was observed, although there was a tendency for lower numbers of wildlife observed when more dogs were available. The
average home range size of eight GPS collared dogs was 2.26 km2 (range 0.10 - 8.11 km2). Distance from manyattas (Masai settlements), revealed a significant positive correlation with wildlife
abundance, which suggest that human settlement and activity has a negative effect on wildlife.
Dogs in the MNC had the potential to interact with the native wildlife at several levels, such as pathogen vectors, agents of disturbance, predators and competitors. To minimize the dog-wildlife interactions and human-wildlife conflicts, a multipronged approach is recommended. A
combination of vaccination, lethal control, restriction of free-ranging behavior and implementation of a trained guarding dog is suggested. The empirical data presented in this paper calls for more studies to make more informed decisions for conservation and management of the MNC.
Introduction
The increasing human population inhabits almost every corner on earth, with severe impact and consequences to the natural environment. Wherever humans settle they bring their domestic animals, which results in both purposeful and accidental introduction of a number of alien species into new habitats and ecosystems all over the world. Dogs (Canis familiaris) are the most abundant mammalian carnivore in the world, with a population estimated to approximately 700 millions (Hughes, J., Macdonald, D. W. 2012). In human settlement areas bordering national parks and wildlife reserves, dogs are kept to avoid inevitable human-wildlife conflicts (HWC), primarily livestock predation by wild carnivores. However these dogs are often unvaccinated and free-ranging and may potentially interact with wildlife at multiple levels, including as reservoirs and vectors for pathogens, predators, agents of disturbance and competitors (Butler, du Toit & Bingham 2004).
The ecosystem of Masai Mara in Kenya is world famous for its abundance and diversity of wildlife.
Despite its importance for numerous of wildlife species including the annual migration of
wildebeest (Connochaetes taurinus), less than half of the area is under protection. The ecosystem is under increasing pressure, and human activities, especially human settlement is the biggest threat to the wildlife habitats. In the Masai Mara is the potential for ecological interactions between dogs and wildlife are higher than ever, due to the increasing permanent human settlement, and the impacts of the increasing abundance of free-ranging dogs are of rising concern for conservationists. Despite this, very little is known about the dynamics and ecological impact on the native wildlife
populations. The most investigated interaction is the role of dogs as vector or reservoir for
pathogens including rabies, canine distemper virus (CDV), canine parvovirus (CPV) and sarcoptic mange. Dogs have been proven partly responsible of transmitting CDV, which killed 30% of the lion (Panthera leo) population in the Serengeti National Park in less than one year in 1994
(Brickner, 2003, Roelke-Parker et al., 1996). Further dogs were as well linked to the transmission of rabies to the African wild dog, which led to local extinction (Lycaon pictus) in Masai Mara in 1989 (Pain, 1997, Woodroffe, 1999). Studies in Tanzania have further associated CPV with mortality of African wild dog pubs (Creel et al., 1997; Woodroffe, 1997). Additionally dogs are mentioned as a potential link to the transmission of the mite Sarcoptes scabiei that cause sarcoptic mange.
Sarcoptic mange was regarded as one of the main infectious causes of mortality in the cheetah (Acinonyx jubatus) population in the Masai Mara (Mwanzia, 1995; Ngoru and Mulama, 2002) but has also been affecting Thomson’s gazelles (Eudorcas thomsonii) wildebeests (Connochaetes taurinus), and livestock (Gakuya et al., 2012).
In the private Mara North Concervancy (abbreviated MNC), bordering the world famous Masai Mara National Reserve, impacts of dogs had never been investigated. Obtaining knowledge on the impact of dogs on wildlife is essential for setting up the future conservation and management schemes. The aim of this paper is to clarify some of the current potential threats and impacts of the increasing dog population in the MNC. Based on studies linking dogs with pathogen transmission to wildlife (Cleaveland et al., 2000; Alexander, 1993), I examined whether dogs in MNC were exposed to pathogens and thereby posing a potential transmission risk to the native wildlife. To gain
information on the prevalence of CDV, CPV, sarcoptic and intestinal parasites in dogs, a serological survey of stray dogs (free-ranging and ownerless) was conducted.
When disturbed, larger mammals often tend to escape over long distances and are likely to be displaced from their home range, stressed physiologically, and experiences the negative effects of the escape for longer durations (Gompper, 2014). I investigated whether the number of dogs had a disturbing effect on the abundance of wildlife, in an observational survey conducted along transects.
It was expected that a negative correlation occurred between number of dogs and wildlife abundance. Additionally, to assess the potential for interactions between free-ranging dogs and wildlife, dogs were GPS collared to gain information on free-ranging behavior and home range size.
In order to contribute to and improve the management of HWC in a responsible and sustainable manner, an ethnographic questionnaire survey among the local Masai community was conducted.
The questionnaire survey was also used to gain information on interactions between dogs and wildlife.
Methods and materials Study area and species
The study was conducted between January and April 2014 in the Mara North Conservancy (MNC) along the northeastern border of Masai Mara National Reserve in south-western Kenya. The conservancy (1°13S, 35°07E, altitude 1570m) consists of 300 km2, primarily savannah grassland and scattered bush land with riparian forest along the seasonal watercourses. This region
experiences a rain season from April to June and in October with an annual precipitation of 1200 mm. The dry season is from December to March and the temperature range is 15-35°C.
The study area includes several human settlement areas, including the towns Mararianta and Aitong with a combined human population of app. 11.000 inhabitants. The dominating land use is
subsistence pastoralism and wildlife tourism/conservation. Land rights and legal ownership are equally distributed and related to the individual Masai families in the conservancy. A unique partnership between landowners and 11 safari camps in the area ensures landowners a fixed monthly income, paid as a conservation fee from the safari camps, to set aside land purely for the purpose of wildlife, creating a conservancy area. This has created zones where livestock are allowed to graze (grazing zones), and non-grazing zones purely set aside for wildlife. The Masais settle primarily along the boundaries of the conservancy and traditionally dependent on livestock farming, being the dominating production form in the area. This means that interactions between livestock, human and wildlife is frequent. Livestock species consisting of mainly goats, sheep and cattle, which are kept in fences (bomas) made of branches and thorny bushes during nighttime. The traditional Masai village, or manyatta, consists of a collection of wooden-frame huts, covered with mud and dung, surrounding a central boma.
Dogs
Due to an increased permanent human settlement, a growing population of dogs (Canis familiaris) have been reported in the study area. The dogs are used for guarding livestock at night against predators, primarily spotted hyenas (Crocuta crocuta), leopards (Panthera pardus) and lions (Panthera leo). The majority of dogs are owned and dependent on humans for their basic needs, although with unrestricted ranging in the area. Many of them are reproduce
uncontrolled/unrestricted. Commonly these dogs are referred to as free-ranging dogs.
Wildlife
As for the rest of the Serengeti-Mara ecosystem, the MNC offers habitat to a large diversity of wildlife. The resident herbivores including gazelles (Gazelle thomsonii and G. granti), impala (Aepyceros melampus), topi (Damaliscus lunatus), Coke’s hartebeest (Alcelephus buselaphus cokii), African buffalo (Syncerus caffer), African elephant (Loxodonta Africana), Common eland (Taurotragus oryx) and the Masai giraffe (Giraffa camelopardalis tippelskirchi).
From July to October, the resident populations of wildebeest (Connochaetes taurinus) and zebra (Equus Burchelli) are joined by the large migrant herds from the Serengeti in Tanzania. The
dominating carnivores in the MNC is spotted hyena (Crocuta crocuta), African lion (Panthera leo), leopard (Panthera pardus), black-backed jackal (Canis mesomelas), cheetahs (Acinonyx jubatus) and mongoose sp. (Mungos mungo, Helugale parvula, Ichneumia albicauda).
Field methods and data collection
Serological method of pathogen identification
To monitor the prevalence of pathogens of stray dogs, a team of rangers, local police, researchers and a veterinarian, culled 31 randomly selected ownerless dogs. The dogs were culled by firearms in the area around Aitong and Mararianta (Map 1, Appendix 2.). Blood were collected from the heart and sampled in 1.3 ml Li-Heparin vacutainers to prevent coagulation. Serum was separated from the plasma, using a centrifuge, and sent to Bora Biotech Laboratories Ltd in Nairobi, where serum samples were screened for antibodies against canine distemper virus (CDV) and canine parvovirus (CPV). Determination of CDV and CPV antibody levels was done by Enzyme- Linked immune-sorbent assay (ELISA) technique using TiterCHECK® CDV/CPV testing kit
(SYNBIOTICS, San Diego USA). The test procedure was performed according to the
manufacturer’s instructions. Reading of results was by comparing the intensity of the blue color of test samples to that of a positive control visually and by using an ELISA reader (450nm). For CDV, a positive test result indicates a serum neutralization titre of 1:16 or greater, and a negative test indicates a serum neutralization titre of less than 1:16. The test sensitivity and specificity are 98%
and 93%, respectively. For CPV, a positive test result indicates a hemagglutination titre of 1:80 and above, and a negative test result indicates a hemagglutination titre of less than 1:80. The test
sensitivity and specificity are 88% and 95%, respectively. The 31 faecal samples were analysed for intestinal parasites through Faecal Egg Count Technique. Skin scraping was only taken from dogs with clinical signs and symptoms of sarcoptic mange. 13 skin samples (scrapings) were analysed through microscopy for the mite, Sarcoptes scabiei that cause sarcoptic mange. Both faecal and skin samples were analysed by the veterinary department at Nairobi University.
Abundance data
A survey on wildlife abundance around manyattas was conducted as an observational study on eight preselected manyattas in the MNC; four manyattas with few dogs (n ≤ 5) and four with many dogs (n ≥15) (Map 1, Appendix 2.). The selected manyattas were at isolated locations as far from other manyattas as possible and close to the protected wildlife area (core area) of the conservancy. Four transect lines in southern, northern, eastern and western directions were made with a handhold compass and GPS. A distance of 500, 1000 and 1500 meter from the centre of the manyatta was GPS mapped on each transect line. Each manyatta had 12 GPS observation points, which were visited 10 days at random times of the day between 8 am and 5 pm in order to take advantage of favourable counting conditions (light, weather). The abundance of the most common species (Thomson’s gazelle, zebra, wildebeest and topi) was filed. All other species of mammals observed were counted and put in the category as “other”. The observations at each GPS observation point were made from a vehicle using the naked eye and binoculars.
GPS data
To get information on dogs’ home ranges and habits, eight owned male dogs were collared with the 250-320 gram GPS-GSM Lite Collar from Savannah Tracking Ltd (Savannah Tracking Ltd,
Bendera Lane 32, Nairobi, Kenya). The collars were set to track every hour, and report coordinates every sixth hour. The data were converted and plotted on Google Earth maps. The dogs were selected from households that were willing to participate in the study and were as close to the core of the protected area as possible. Due to aggressive behaviour to strangers, the owner handled the dog during collaring. (Map 2, Appendix 3)
Ethnographic data
Information on dog-wildlife interactions and factors associated with dog ownership, including HWC, within the MNC, was gathered from a questionnaire survey of a total of 97 dog-owning households (DOHH). The questionnaire contained both structured questions with binary variables (“yes” or “no”) and semi structured with binary questions followed by an open question in which the respondents were free to provide open responses. The survey included questions regarding dog ownership; number of dogs owned, sex, age, factors associated with dog ownership, demographics,
fecundity, reproductive history, litter size, food provided for the dogs, management and interactions with wildlife, vaccination, future management suggestions but also general household information.
Prior to each interview the head of the household was informed about the purpose of the study, which was only conducted after a verbal consensus. The 97 interviewed respondents were primarily men. In the traditional Masai culture, women are not authorised to discuss livestock with visitors without permission from their husband. The survey was carried out in localities of Mararianta, Aitong and Enkekwei, which are the major permanent settlement areas in the area of the MNC, and where a lot of free ranging dogs were present. Each interview lasted 30 minutes and was conducted together with a local Masai safari guide and conservationist to overcome the language barrier.
Questions were read aloud in English and translated to Maa (Masai language). (Questionnaire, Appendix 1)
Ethics The study was approved by the Mara North Conservancy Advisory Board, the Veterinary Services Division of the Ministry of Agriculture, Livestock and Fisheries and Kenya Wildlife Service (KWS) in Kenya. The research permit was granted by the Ministry of Higher Education, Science and Technology. A special permission to cull dogs by firearms was given by the Deputy County Commissioner of Narok South. Guidelines and protocols were followed. In all sites, verbal consent was obtained prior to each survey from the community leaders and respondents, who were kept fully informed of the purpose, approach and progress of the study.
Statistical analysis
Prior to the statistical analysis and modelling of the observation data, data were tested for
homogeneity of variance (Levene’s Test F= 0,05, p= 0,81), and normality of residuals, to meet the assumptions for normal distribution. Data were transformed (Johnson SI, Goodness of fit, Shapiro Wilk W = 0,98). The effect of number of dogs on abundance of wildlife was tested, using mixed models ANOVA with “Dogs”, “Distance” and “Time of day” as fixed variables and “Manyattas” as random effect to account for the potential variation among them. “Time of day” was originally divided in “morning” (8am-12am) and “afternoon”(12am-5pm). Despite a significant effect (p = 0,04) in the abundance of “other” no statistically significant difference (Student’s t-test, F-ratio = - 0,02, p = 0,98) in wildlife abundance was found, and it was decided to pool the “Time of day” data.
Both the total abundance of wildlife, where all species are pooled, and the abundance of each species were analysed to investigate any effects on abundance of the number of dogs. All statistical analysis was performed in the software JMP version 10 (JMP Statistical DiscoveryTM from SAS).
Results
Serological results
Among the 28 blood samples that were suitable for analysis (3 of the 31 samples were haemolysed), 25% (95% CI [0,107; 0,449]) were tested positive for antibodies of canine distemper virus. 67,8%
(95% CI [0,477; 0,841]) was tested positive for antibodies of canine parvovirus. From the 13 skin samples, none were tested positive for the mite Sarcoptes scabiei, which cause the skin disease sarcoptic mange. From the 31 analysed faecal samples, three were positive for intestinal parasites.
Two samples had round worms (Toxocara canis ascaris), and one had both Toxocara canis ascaris and hook worms (Ancylostmum caninum and Uncinaria stenocephala). (Table 1.)
N samples Percentage 95% CI
Canine Distemper Virus 28 25% (7/28) 10,7 % – 44,9%
Canine Parvovirus 28 67,8% (19/28) 47,7% -84,1 %
Sarcoptic mange 13 0% (0/13) 0 % - 24,7%
Hook Worms
(Ancylostoma Caninum)
31 3,2% (1/31) 0,1% - 16,7 %
Round Worms (Toxocara canis ascaris)
31 9,6% (3/31) 2,0 % - 25,8%
Table 1. Percentages and 95% confidence interval of the positive serological tests of stray dogs in the Mara North Conservancy.
Abundance data
Number of dogs showed no statistical significant effect (p = 0,18) on the total abundance of wildlife around the tested manyattas (table 2. and fig. 1). Although not statistically significant, there was a trend towards 32,6% fewer observed numbers of wildlife in transects with more dogs. Additionally, no statistical significant effect was found on any of the individual wildlife species (fig. 2). Time of day (morning and afternoon) (table 2. and fig. 3.) showed no statistical significant effect (p = 0,81) on the total wildlife abundance, or on species except for the category “other”, where the abundance of wildlife was higher in the morning (p = 0,04). Distance from the manyatta (fig. 4.) however, showed statistical significant effects on the abundance of total wildlife and for each species. The particular manyatta had up to 43,9% explanatory effect on the abundance of wildlife (random effect) indicating large variation of each specific manyatta or location that must be accounted for in the analyses.
The home ranges for the eight GPS-collared owned male dogs varied considerably in size from 0.10 km2 to 8.11 km2. The average home range size was 2.26 km2. One individual moved as far as 3.5 kilometres from its home (Map 2., Appendix 3.).
Model N DF F-ratio Prob. > F
Total_Dogs 1 1 2,27 0,18
Total_timeofday 1 1 0,05 0,81
Total_distance 2 2 39,42 < 0,0001
T.gazelle_Dogs 1 1 2,22 0,18
T.gazelle_timeofday 1 1 0,06 0,80
T.gazelle_distance 2 2 18,78 < 0,0001
Zebra_Dogs 1 1 1,19 0,31
Zebra_timeofday 1 1 0,35 0,55
Zebra_distance 2 2 10,55 < 0,0001
Wildebeest_Dogs 1 1 1,00 0,35
Wildebeest_timeofday 1 1 2,26 0,13
Wildebeest_distance 2 2 11,51 < 0,0001
Topi_Dogs 1 1 0,08 0,79
Topi_timeofday 1 1 2,57 0,11
Topi_distance 2 2 19,99 < 0,0001
Other_Dogs 1 1 0,32 0,59
Other_timeofday 1 1 4,14 0,04
Other_distance 2 2 15,78 < 0,0001
Table 2. Summary of the multivariable analysis models of factors associated with wildlife abundance (“Dogs” = number of dogs (few or many), “Time of day” = morning and afternoon,
“Distance” = distance from manyattas). “Total” is where abundance of all observed wildlife species are pooled. “Other” is all other observed species of mammals pooled. Manyattas was set as a random effect (n=8). α = 0,05.
Fig. 1. The effect of number of dogs on the total abundance of wildlife. Few = n ≤ 5 dogs, Many = n ≥ 15 dogs. Median (Few = 93, Many = 32). Quartile range (Few = 42,5-187,2; Many = 8,7-92,7).
95% confidence interval.
Fig. 2. The effect of number of dogs on total wildlife abundance and on each species. Error bars represent standard error of mean.
0 200 400 600 800 1000 1200 1400 1600
Few Many
Abundance
Dogs
0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000
Few Many
Abundance
Dogs
Total Tgaz Zebra Wildebeest Topi Other
Fig. 3. The effect of time of day on wildlife abundances. Error bars represent standard error of mean.
Fig. 4. Abundances of wildlife at different distances from the manyattas. Error bars represent standard error of mean.
-‐2000 0 2000 4000 6000 8000 10000 12000 14000 16000
Morning Afternoon
Abundance
Time of day
Total T.Gazelle Zebra Wildebeest Topi Other
-‐2000 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000
500 m 1000 m 1500 m
Abundance
Distance from manyatta
Total T.Gazelle Zebra Wildebeest Topi Other
Ethnographic results
A total of 641 dogs were recorded which corresponded to an average of 6,6 dogs per household.
24,9% were female and 54,9% were males (Appendix 1), resulting in an overall female:male ratio on 1:2,2. Pubs were excluded from the survey and uncertainty about the sex occurred as well. No record on the population size of dogs exists in the study area. An estimate of the population within MNC, including the areas of Mararianta, Lemek Hills and Aitong was based on a combination of human:dog ratio and average dogs pr. household. The total number of households within the study area was 344 and the human:dog ratio in rural Kenya is 8:1 (Kitala et al. 2001). The current dog population size was estimated to approximately 2500. Within the 96 DOHH, the number of owned dogs span from 1 to 30 individuals. The single household that owned no dogs, gave the reason that a leopard had eaten the dog and they had not yet replaced it. The main reason for keeping dogs was due to livestock ownership, and therefore protection of livestock from wild carnivores at night was fundamental. The primary predators were spotted hyenas, leopards and lions. The dogs barked at and chased spotted hyenas away, but when lions and leopards were near the dogs only barked and alerted the household. The majority (77%) of the respondents wanted aggressive dogs and preferred males, which were believed to be better guarding dogs. Additionally, 42% of the respondents were of the opinion that a greater number of dogs served better protection. 39% were satisfied with their number of owned dogs and 8% preferred less, due to the expenses related to dog ownership. All the respondents fed their dogs regularly, with food consisting of, mainly ugali (local maize flower pudding) and leftovers. Dogs did also scavenge from domestic and wild carrions. Only dogs in one household were vaccinated against rabies, but the majority of DOHH vaccinated their dogs in the same way as livestock with veriben, against sleeping sickness (trypanosomiasis) and other
protozoan diseases. Finally 94,8% of the DOHH experienced conflict with wildlife with regard to loss of livestock. It was primarily spotted hyenas, leopards and lions that were predating on livestock at night. 64,5% of the DOHH had lost dogs to wildlife with leopards responsible in most cases. Due to a successful HWC-decreasing project in Namibia, the last question in the survey was whether the dog owners were willing to exchange their dogs for a trained guarding dog (Anatolian shepherd dog) to decrease the conflict regarding loss of livestock. 74,2% was willing to exchange their dog for a trained guarding dog, although they expressed scepticism about whether it would be effective in decreasing the HWC.
Discussion
The results of the serological analysis are consistent with the hypothesis that dogs in the MNC are exposed to transmittable pathogens, especially with regard to CPV and CDV. The dogs in MNC can potentially act as vectors, and there is a potential and risk for pathogen transmission from dogs to wildlife, which also is consistent with previous studies (Cleaveland, 2000; Alexander, 1993, 1994).
CPV is one of three closely related parvoviruses that infect wild predators of the order Carnivora, and have been associated with mortality among African wild dog pubs (Lycaon pictus) (Creel et al., 1997; Woodroffe, 1997). CPV is extremely stable and able to survive for several months in the
environment. Large amounts of virus are shed in feces of infected animal, but only for short periods (7-10 days) (McCaw and Hoskins, 2006). Indirect transmission through environmental
contamination is therefore likely to play an important role in the maintenance and transmission of CPV. Alexander et al. (1993, 1994) found high prevalence of antibodies to parvovirus in African wild dogs (Lycaon pictus), Black-backed (Canis mesomelas), Golden (Canis aureus) and Side- striped (Canis adustus) jackals in Kenya, which was assumed to be spread from infected dogs.
However, few studies have demonstrated an impact of CPV on wild populations, and no studies have explored the role of dogs in transmitting the disease in detail (Gompper, 2014). Additionally, 25% of the sampled dogs were tested positive for antibodies to CDV, which only supports the potential risk for pathogen transmission. CDV is estimated to be fatal in 50% of cases when affecting adult dogs and 80% when affecting puppies (Baker Institute for Animal Health). Studies on CDV outbreaks show that the same CDV variant may circulate among several host species (e.g.
African wild dogs, bat-eared foxes, black-backed jackals and spotted hyenas) in a given geographic area, with evidence of frequent interspecies transmission (Carpenter et al., 1998; Gowtage-Sequeira et al., 2009; Haas et al., 1996). The majority of the sampled dogs did not show clear signs or
symptoms of infection, even though they expressed antibodies. Consequently dogs can serve as
“healthy” pathogen vectors. Factors influencing the pathogenesis of CPV, CDV and sarcoptic mange are the immune status of the respective host and the virulence (number of viral particles) (Baker Institute for Animal Health).
The epidemiology of sarcoptic mange in wildlife populations is not well understood and seem to differ between areas of the world and animal species (Bornstein et al., 2008). In Masai Mara,
sarcoptic mange has been found both in livestock, except for sheep, and wildlife including cheetahs, lions, African wild dogs, Thomson’s gazelles and wildebeests (Gakuya el al., 2012). It is suggested that the Sarcoptes mite is spread from domestic animals (Pence and Ueckermann, 2002) and amongst wildlife through prey-predator interactions (Gakuya, 2011). Sarcoptic mange is a difficult disease to diagnose because the Sarcoptes mites are hard to find on skin scrapings. Examination of skin scrapings is the best method to test for sarcoptic mange, and several scrapings are usually taken at predilection sites (fore and hind limbs, ischium, base of ears). The 13 skin scrapings, in this study were typically taken at one predilection site and repetitive examination was not practiced. The negative test results are therefore not necessarily tantamount to that none of the sampled dogs were positive for sarcoptic mange. Although no skin scrapings were tested positive, it is suggested that the presence of livestock and dogs in a wildlife habitat, potentially pose a risk of transmission and host source.
Dogs were frequently reported to be preyed upon in the MNC by wild carnivores, predominantly leopards, but also spotted hyenas and lions were mentioned as predators of dogs in the
questionnaire survey. This kind of physical contact provides an ideal source of transmission of infectious pathogens. CDV is spread in aerosol droplets from respiratory secretions or through contact with infected body fluids, including nasal and ocular secretions, feces and urine.CPV is spread through contact with infected feces. Transmission of the sarcoptes mite is typically through direct physical contact with a mite-infected animal. Alternatively, transmission may be indirect since mites can survive for some time off their hosts and still remain infective for new host individual (Arlian, 1989). During the study, dogs were regularly observed scavenging from wild
carcasses, which adds to the potential risk of transmitting pathogens. Additionally the social
ecology and cleptoparasitic behavior of both dogs, spotted hyenas and lions can easily ensure rapid intra- and interspecies transmission. Dogs may rarely get in close contact to lions to transmit
pathogens directly, hence it is very likely that spotted hyenas, jackals (Canis mesomelas, C. aureus, C. adustus) or other, has an intermediate role in the transmission of pathogens. Both species were strongly implicated as vectors and possible reservoirs to the epidemics in lions and African wild dog in Tanzania and Kenya (Roelke-Parker et al., 1996; Hofmeyr et al., 2000; Alexander et al., 1994).
The intestinal parasites Ancylostoma and Toxocara canis ascaris were found in one and three of the dog samples, respectively. Little is known about the effects of intestinal parasites in African
wildlife, however studies on lions (Panthera leo) in Tanzania and spotted hyenas (Crucota crucota) in Kenya have revealed that the majority of the investigated animals were infected by some species of intestinal parasites (Müller-Graf, 1995, Engh et al., 2003). The most common parasites found were the cestode Spirometra spp. and Ancylostoma sp. Other parasites found were Taeniidae sp., Coccidian sp., Isospora sp., Spirurida sp, Toxocara sp., Mesocestoides sp., Dipylidium sp. and Trichuris sp. The source of these parasites and their route of transmission are unknown, but it is suggested that it is from ingestion of parasite-infected prey (Müller-Graf, 1995).
In the local communities in the MNC, dogs are considered very important for protection of livestock. The current dog population in MNC is estimated to approx. 2500 dogs. With a human population growth rate at 2,1% in rural areas in Kenya (UN Data 2011) and only very little changes in the traditional life as pastoralists, it seems reasonable to assume that the dog population also will increase. As the dog population increases, so does the potential for interaction with wildlife at multiple levels.
Contrary to expectations, no significant effect of number of dogs on abundance of wildlife was found, however a non-significant trend showed the expected negative correlation between number of dogs and abundance of wildlife. Time of day also appeared to not have any significant effect on either total abundance or on specific species numbers, although broad categories of time of day (morning or afternoon) and the fact that dusk and dawn were not included suggests that this result should be taken with caution. Time of day only matters for the category “other wildlife” but this result may be explained by a large herd of buffalos (Syncerus caffer) observed on one particular morning (fig. 3.). Distance from the manyatta was the only statistically significant predictor of wildlife abundances. Distance from the manyattas was positive correlated with the abundance of wildlife, which may be explained by several factors. Disturbance is believed to be the most important factor, and dogs are far from the only disturbing factor in the study area. The level of human activity, including herding livestock, is very likely to be a great factor of disturbance. The Masais are completely dependent on their livestock and herd them both around the manyattas and over large distances on a daily basis for grazing. The area around manyattas is often excessively over-grazed by the livestock, which might add to the explanation why wildlife might tend to avoid these areas (low food source availability). Another factor to be considered is the geographical location of the manyatta. Up to 43,9% of the abundance of wildlife around the examined manyattas, was explained by the specific manyatta (random effect). Some settlements were located very close
to each other, while others were completely isolated. Yet again others were close to the restricted wildlife area or reserves. Dependent on the location of the settlement, human activity varies
considerably, and so does the wildlife abundance. Human settlements and activities and its negative impacts are a well-known phenomenon in Africa (Newmark, 1996; Kideghesho et al., 2006). In the MNC where humans exist naturally, contrary to reserves where settlements are prohibited, findings indicates that the settlements are affecting wildlife in several negative ways, which is consistent with several studies (e.g. Stephens et al., 2001; Fritz et al., 2003) proving that settlement and human activities have negative effects on the abundances and diversity of wildlife. Establishing human settlement in wildlife migratory areas such as Masai Mara is becoming common and is endangering many wildlife species (Ogutu et al., 2012). Despite the importance of Masai Mara for one of the worlds last great migrations, less than half of the area is under protection. The rest is private land without any kind of conservation and management efforts. The human population growth bordering protected areas has become a serious threat to management of wildlife all over Africa (Nichols, 1999), whereas the amount and distribution of future settlement is a topic of great importance in the years to come for the management in the MNC.
Contrary to the general indication by the local people, the GPS survey and personal observations during the field study showed that dogs were roaming far from their respective owner. This clearly suggests that free-ranging dogs may interact with numerous species of wildlife, due to overlapping home ranges. Dogs were for instance observed taking over wildlife carcasses from big flocks of vultures. This type of competitive interaction is believed to be frequent and very devastating for the populations of vultures. Additionally dogs were also observed chasing different kind of herbivores and birds, which is consistent with the results from the questionnaire survey, where 27% of the respondents had seen their dogs chasing other wildlife than predators, without killing them. This kind of disturbance has been documented to have severe consequences for wildlife populations, with regard to home range displacement, physiological effects, reproductive success etc.
(MacArthur et al., 1982; Preisser et al., 2005; Zanette et al., 2011.).
It is indisputable that HWC is a big problem in the MNC as 94,8% of the livestock owning
respondents frequently lost livestock to predators despite of keeping dogs. Depredation of livestock represents an economic concern, and has traditionally been responded by killing the problem- causing animal. This is now illegal and has changed the conflict between people and wildlife into a political conflict. As a conservation strategy, MNC has incorporated compensation payments to the livestock owners to mitigate the conflicts and prevent the locals from killing problem-causing wildlife. Compensation programs may be a good way to get acceptance and “apologize” to the local livestock owners, however is does not prevent conflicts from happening. An effective management strategy in lowing HWC in relation to loss of livestock is the introduction of a better and trained guarding dog. The Anatolian Shepherd dog has significantly decreased HWC by nearly 100 % in rural areas of Namibia (Marker et al., 2005). Implementing the use of this breed in the MNC is believed to have positive effect on the HWC, by substituting the traditional Masai guarding dogs and reducing the compensation payments.
Conclusion
My findings indicate that dogs in MNC are a potential risk in transmission of pathogens to wildlife and potentially other negative effects as well. Action must be taken to mitigate any dog-wildlife interactions. Furthermore, my findings suggests that human settlements and activity have a strong negative effect on wildlife abundance, and should be avoided if possible, especially in areas nearest the protected wildlife areas. To gather settlements in a very few areas (settlement zones) is believed to be of great advantage for the wildlife, however it is expected to be met with local resistance by the Masai community.
Management tools must be implemented to decrease the human-wildlife conflicts within the MNC, which is of great concern for both wildlife conservation and the Masai community. 94,8% of the respondents were frequently experiencing large carnivores predating on their livestock, despite having dogs for guarding. To lower HWC and simultaneously minimize the risks of dog-wildlife interactions, a multipronged approach is fundamental. A combination of vaccination, lethal control and restriction of free-ranging behavior may be effective in lowering the potential deleterious effects of dogs. Additionally an introduction of a trained and vaccinated guarding dog (e.g.
Anatolian Shepherd dog), which has proven successful in lowering HWC, would probably be beneficial for both wildlife and the Masai community within the MNC.
Even though this study has limitations, it represents some of the first quantitative data on the potential threats of dogs to wildlife, and such knowledge is of great importance for effective and sustainable conservation and management of the MNC. The same scenarios and threats at those described here, are likely to occur in similar areas of the Masai Mara-Serengeti ecosystem, and should give rise to additional future research on the impact of dogs on wildlife, with the aim of improving and supporting the conservation of one of the world’s most spectacular wildlife habitats.
Appendix 1.
Questionnaire for dog owners
1. How are livestock managed during the night?
-‐ what type of bomas? Traditional?, steel?, electric wire?, non-‐el wire?
100 % Traditional bomas
2. Do you keep dogs? Yes No 98,9% answered yes -‐ How many? Average 6,6 pr. household
-‐ Sex? 24,9% females, 54,9% males -‐ Age? Most did not know
-‐ Names? Only the children now -‐ Number of births? Most did not know -‐ Litter size? Most did not know
3. What is the purpose of keeping your dogs?
-‐ Used for all hoofstock? (goats, sheep, cattle) -‐ Guarding? 100% for guarding all livestock
4. Is it important for you to have a dog? Yes No 100 % answered yes
-‐ How many? Answers varied from 1 to 50 dogs. 42% needed more, 39% were satisfied, 8%
needed less dogs.
-‐ How many are used for guarding? 100% answered all of the dogs
Why? Most did not know, 42% answered that more is better, 6,2% would have less due too the food expenses.
5. How did you choose your dog?
-‐ Where did you get it from? All got the dogs from friends and neighbours.
-‐ What criteria would you consider important for a good dog? 77% wanted aggressive males. Other criteria mentioned were size and colour.
6. Are there any expenses related to keeping dogs? 100% answered yes
-‐ Food? – From where? 100% answered that they provide food for their dogs. Primarily local ugali (maize flower pudding). Or leftovers if there is any.
-‐ Vaccination? 1% answered that their dogs are vaccinated against rabies, 23,9% would treat their dogs if it show any sign of illness, 54% answers that dogs are treated against sleeping sickness the same way as livestock
-‐ Treatment for worms? How and with what? 2% answered that the dogs were treated for worms -‐ Castration? NO
-‐ Natural Medicine? NO
7. Is it difficult to keep dogs alive in mara? Yes No 16,7% answered yes. 83,3% answered no -‐ Why? Expenses related to food
8. Do you experience conflicts with wildlife? Yes No 94,8% answered yes
-‐ What kind? 94,8 % answered spotted hyenas, lions and leopards. Also hippopotamus, elephant and crocodiles was mentioned
-‐ loss of livestock (goat, sheep, or cattle?) 94,8% answered yes
9. How does the dogs react towards wildlife? 100% answered that the dogs will bark and chase away hyenas, but only bark when lions or leopards are near.
10. What kind of wildlife do your dogs chase away from your livestock/hoofstock areas? 64,5% answered only predators. 28,1% answer all species of wildlife. The wildlife chased, was primarily white-‐bearded wildebeest (Connochaetes taurinus), Zebra (Equus burchelli), Topi (Damaliscus korrigum), Impala (Aepyceros melampus), Thomson’s gazelle (Eudorcas thomsonii) and warthogs (Phacochoerus africanus).
11. Have any of your dogs been killed by wildlife? Yes No 64,5% answered yes
-‐ By what? Primarily leopards (91,8%), but also spotted hyenas, crocodiles were mentioned.
12. Have you observed dogs exposing aggressive behaviour against human or wildlife?
Yes No 100% answered yes
-‐ Have persons been bitten? 20,8% answered yes
13 Any favourite snacks for your dogs in the field?
Reptiles Rodents Aves Mongoose Antelopes Carcass
96,8% answered that dogs would eat carcass, and 6,4% answered that dogs would also hunt antelopes.
14. Would you be willing to exchange your dog for a trained shepherd/guardian dog?
-‐ Yes No 74,2% answered yes. 25,8% answered no.
Appendix 2.
Map 1.Mara North Conservancy. Red points are settlements. Yellow points (n ≤ 5 dogs) and purple points (n ≥ 15 dogs) indicate the manyattas where transects were performed. Human settlement is prohibited in the core area, and purely set aside for wildlife.
Appendix 3.
Map 2. A satellite image of MNC from Google Earth. Four dogs are collared here (red, yellow, grey purple). Size of home range and distances are measured in Google Earth using polygons.
PART III - Solutions and management guidelines
Conservation actions focusing on reducing human-wildlife conflicts and dog-wildlife interactions will be a challenging task, due to the role of dogs in the traditional Masai culture. To create public awareness within the local communities about the potential impacts of dogs and possible conflict- decreasing alternatives, is believed to be fundamental for enhancing the understanding, acceptance and support of the different management strategies suggested.
There appears to be a legitimate cause for concern in the MNC, regarding multiple potential dog- wildlife interactions. To lower the number of dogs is expected to be a crucial step, in mitigating the risk for e.g. pathogen transmission as well as other interactions. The risk of CDV transmission was suggested to be dependent on dog density in the epidemic of Serengeti lions (Cleaveland et al., 2000). Consequently controlling dog-wildlife interactions, at the junction of protected areas and settlement areas, must involve a multipronged approach. A combination of vaccination,
sterilization, lethal control, removal of un-owned dogs, restriction of free-ranging behavior, improvement of feeding and a strong emphasis on responsible dog ownership are just some of the strategies suggested. Well-implemented mass-vaccination of potential pathogen reservoir and host dogs may provide a powerful management tool, which for example has resulted in the elimination of rabies in wild populations in large parts of the Serengeti (Lembo et al., 2010). Maintaining high vaccination coverage (60-70%) through repeated campaigns is crucial for mitigating pathogens such as rabies (Cleaveland et al., 2003). With respect to CDV and CPV, the vaccination effectiveness is unknown, due to lack of understanding of the maintenance of the viruses in the ecosystem. Mass sterilization is often used as adjunct to vaccination programs, and advocated as a necessary
component of disease and population control (Cleaveland, 2003). The majority of dogs in the MNC were owned, which make them very accessible for vaccination- and sterilization programs. When considering strategies, two fundamental questions must be addressed: 1) are the consequences of the pathogen transmission severe enough to consider removing the risk of infection imposed by dogs (by e.g. vaccination, population control etc.)? and 2) if the conservation managers are
logistically able to remove the contribution from dogs, what is the likelihood that the pathogen still persists in the broader animal community? To answer these questions an epidemiologic framework is required.
The majority of studies on free-ranging dog and their impact on wildlife have so far been on the risk dogs pose for spreading zoonotic diseases. In cases where dogs have been involved as the source of pathogens, causing widespread mortality in carnivores, the major action has been on reducing the potential for transmission via vaccination (e.g. Cleveland et al. 2007), rather than on population control or restricting ranging-behavior (Gompper, 2014). Mitigating the risk of pathogen transmission does not reduce the possibility for other kinds of dog-wildlife interactions, and the potential for dog-wildlife interactions, depends on dog density and ranging behavior (Vanak and Gompper, 2010). Lethal population control, by repeated culling (only shooting), may be an
effective way of controlling dog populations, lowering the potential for pathogen transmission and other dog-wildlife interactions. However culling has to be considered carefully due to the
