Behavioural Ecology of Free-ranging and Reintroduced African Wild Dog (Lycaon pictus) Packs in the Serengeti Ecosystem, Tanzania

Worldwide, large carnivore conservation has become an increasing challenge in the face of human population growth and anthropogenic development adjacent to protected areas. African wild dogs (Lycaon pictus) range widely and have low population densities. Such behaviours may expose the species to more anthropogenic influences than other large carnivores. The Loliondo Game Controlled Area (LGCA) is characterized by a recently increasing human population with the majority being semi-nomadic Maasai pastoralists. The area has simultaneously accommodated an average of 10 packs of wild dogs, totalling about 120 individuals per year for the past decade. The packs range in different areas, avoiding areas near village centres, and the highest mean numbers of sightings were located in treed shrubland vegetation. Furthermore, retaliatory killings of wild dogs through poisoning of adult wild dogs and burning of pups in dens by local people due to livestock depredation, represents the greatest threats to wild dog conservation in the area. An analysis of dispersal movement behaviour revealed the longest distances moved by wild dogs recorded to date. The two disperser groups covered straight-line distances of 250.4 and 520 km. We further observed that the dispersers utilized natural vegetation, as opposed to transformed habitats, more than 90% of the time. In terms of home range utilization and habitat selection by African wild dogs, analysis of GPS satellite collar data revealed that the free-ranging packs had shorter step lengths, higher clustering in June - September and no clear patterns in the net squared displacement (NSD) compared to the reintroduced packs, which had smaller and larger core home range sizes throughout the long and short dry seasons, respectively. The wild dogs also changed foraging behaviours between seasons under different woody covers and selected different landforms during day and night. Hilly areas were preferentially selected during the night, and breaks, hills and low mountains were preferentially selected during daylight hours. Our results further revealed that ten potential prey species of small to medium size herbivores were found within wild dog home ranges, of which Thomson's gazelle (Eudorcas thomsonii), wildebeest (Connochaetes taurinus), impala (Aepyceros melampus) and zebra (Equus quagga) showed the highest mean densities. Furthermore, a faecal analysis showed that Kirk's dik dik (Madoqua kirkii), Grant's gazelle (Nanger granti), impala and Thomson's gazelle had significant spatio-temporal variability. Grant's gazelle and impala were the most preferred species by wild dog packs in the Serengeti ecosystem. Evaluation of the wild dog reintroduction programme showed mixed levels of success after four packs established home ranges in livestock-free areas in the western part of the Serengeti ecosystem. The NSD model indicated that one reintroduced pack showed high release site fidelity. Survival rates for both the reintroduced and free-ranging male wild dogs to the age of 12 months were relatively high, with 68.29 % (n = 28) and 65.38 % (n = 17) respectively. We found no significant difference in survival rate between free-ranging and released individuals, but females tended to have lower survival than males, and pups had significantly lower survival than adults. Furthermore, two reintroduced packs reproduced successfully with an average of six pups survived after denning. Based on our findings, effective monitoring of wild dogs in the Serengeti ecosystem should adopt a multi-institutional approach in a joint effort to conserve wild dogs to attain a long-term viable population. A detailed analysis of the movement behaviour of both resident and dispersing wild dog packs between natural vegetation cover and developed human areas is essential for future assessment of available habitat patches and population connectivity for wild dog conservation. The findings from prey occurrences in the wild dog home ranges suggested that future research should focus on the influence of the landscape features (i.e., topography) on African wild dog prey selection in the Serengeti ecosystem. Lastly, we determined in this study that reintroduction had mixed success based on pack establishment under the two wild dog pack release protocols. Therefore, it is essential to further evaluate the reintroduction programme using longer-term data by incorporating other factors, including the eventual site of establishment, habitat suitability, assessment of community changes in attitudes on livestock depredation incidences by wild dogs in LGCA and wild dog packs utilization during denning into different landscape in the Serengeti ecosystem

Abundance, distribution and conservation threats of African wild dog (lycaon pictus) in the Loliondo game controlled area, Tanzania

Assessment of abundance, distribution and conservation threats to African wild dogs was conducted in Loliondo Game Controlled Area (LGCA), northern Tanzania. Specifically, the study focused on determining population size and structure, spatial distribution, attitudes of local people towards wild dogs and wild dog conservation and threats impacting the species. Semi-structured interviews, diurnal random searches, internal and external examinations of wild dogs carcasses examined and night transect surveys were employed. Eight packs with a total of 132 recognised individuals at an average pack size of 16.50 ± SD 7.50 individuals were recorded. Pack sizes 3 individuals were reported to be sighted mostly and of all respondents (n = 210), only 26% were able to recognise wild dog sexes. The density of both known and unknown wild dogs was 0.19 animals/km 2 , higher compared to other carnivores. In terms of distribution most of the packs were concentrated in the northern part as compared to the central and southern parts of LGCA. The species was observed to occur most in woodland type of vegetation. Interestingly, 55.30% of respondents showed a positive attitude towards wild dogs and wild dog conservation despite that 52.90% of respondents dismissed lack of any conservation action or strategy in place towards conserving the species. However, poisoning and Canine Distemper Virus were identified as the main threats. Therefore, conserving African wild dogs in LGCA requires mult-approach conservation efforts (i.e. awareness rising to community, fitting radio telemetry to the dogs and threats management interventions) due to nature of the species

Population size estimates and distribution of the African elephant using the dung surveys method in Rubondo Island National Park, Tanzania

Research Article published by International Journal of Biodiversity and Conservation Vol. 8(6), June 2016A study to estimate population size and distribution of elephants in the Rubondo Island National Park (RINP) was conducted between March and July 2014. It involved elephant dung survey methods. In estimating elephant dung pile density, a total of 217 dung piles were enumerated in 58 transects (each 1 km). The on-site dung decay rate computed from 100 marked fresh dung piles was estimated to be 0.01542 per day. By combining estimated dung pile density, on-site decay rate and defecation rate of 17 dung piles per day, the study found an estimate of about 102 elephants (95% CI, 72-144). Furthermore, results of this study indicate that, elephants were found to be more concentrated on the central and northern zones, which are the areas of the park that have some open glades allowing elephant to access the area easily to lake shores. The information generated from the study can be incorporated into setting up future management strategies for elephant conservation in RINP

Butterfly Abundance and Diversity in Different Habitat Types in the Usangu Area, Ruaha National Park

Insects are key fauna species that respond quickly to disturbances and environmental changes. They act as good indicators of habitat, community, or ecosystem quality. Among the great diversity of insects, butterflies stand as ideal bio-indicators for ecosystem function and are sensitive to changes in habitat composition and structure. This study was carried out to examine the diversity and abundance of butterflies across the restored habitats in Usangu area part of Ruaha National Park (RUNAPA) from May 2022 to June 2022 using the walking transect method supplemented by sweep nets and butterfly baited traps. A total of six transects of 1 km in length were laid in the four main habitat types selected in Usangu area including grassland, Miombo woodland, Vachellia/Commiphora woodland, and riverine forest. Searches were conducted in the morning and evening. The Miombo woodland and riverine forest habitats exhibited relatively higher species diversity, richness, evenness, abundance, and a higher number of habitat-restricted species, while Vachellia/Commiphora woodland and grassland habitats recorded the lowest diversity and abundance as well as the lowest number of habitat-restricted species. Family Nymphalidae was the most dominant followed by Pieridae while Papilionidae and Hesperiidae were scarce in the study area. This study clearly shows the importance of Miombo woodland and riverine forest habitats in sustaining rich butterfly diversity and abundance in Usangu area. The two habitats must be effectively managed and conserved for sustaining ecological health and integrity of Usangu area. The Usangu area’s Miombo woodland and riverine forest habitats have immense potential for butterfly tourism and they can offer an excellent opportunity to promote conservation efforts and raise public awareness. However, it is crucial to monitor these habitats closely as any environmental changes that may occur could harm the butterfly diversity and abundance in the area. Preserving this wilderness to maintain a thriving butterfly population is of utmost importance

Heading for the Hills: Risk Avoidance Drives Den Site Selection in African Wild Dogs

Compared to their main competitors, African wild dogs (Lycaon pictus) have inferior competitive abilities and interspecific competition is a serious fitness-limiting factor. Lions (Panthera leo) are the dominant large carnivore in African savannah ecosystems and wild dogs avoid them both spatially and temporally. Wild dog young are particularly vulnerable and suffer high rates of mortality from lions. Since lions do not utilize all parts of the landscape with an equal intensity, spatial variation in lion densities can be exploited by wild dogs both during their general ranging behaviour, but more specifically when they are confined to a den with vulnerable young. Since patches of rugged terrain are associated with lower lion densities, we hypothesized that these comparatively safe habitats should be selected by wild dogs for denning. We investigated the relationship between the distribution of 100 wild dog den sites and the occurrence of rugged terrain in four wild dog populations located in Tanzania, Zimbabwe and South Africa. A terrain ruggedness index was derived from a 90 m digital elevation model and used to map terrain ruggedness at each site. We compared characteristics of actual and potential(random) den sites to determine how wild dogs select den sites. The distributions of wild dog dens were strongly associated with rugged terrain and wild dogs actively selected terrain that was more rugged than that available on average. The likelihood of encountering lions is reduced in these habitats, minimizing the risk to both adults and pups. Our findings have important implications for the conservation management of the species, especially when assessing habitat suitability for potential reintroductions. The simple technique used to assess terrain ruggedness may be useful to investigate habitat suitability, and even predict highly suitable denning areas, across large landscapes

No evidence of handling‐induced mortality in Serengeti's African wild dog population

The disappearance of an endangered African wild dog population from Serengeti National Park (SNP) led to international debate centered around one question: were researchers to blame? The “Burrows' hypothesis” postulated that stress induced by research‐related immobilization and handling reactivated a latent rabies virus, eliminating the population. Insufficient data inhibited hypothesis testing, but since wild dogs persisted alongside SNP and have been studied since 2005, the hypothesis can be tested 25 years after its proposition. To be supported, wild dog immobilization interventions should have resulted in high mortality rates. However, 87.6% of 121 handled wild dogs (2006–2016) survived >12 months post‐handling. Some argued that viral reactivation would necessitate long‐term stress. Following immobilization, 67 animals were captured, transported, and held in a translocation enclosure. Despite the longer‐term stress, 95.5% survived >12 months. Furthermore, the stable number of wild dog packs in the ecosystem over the past decade, and lack of recolonization of SNP, strongly oppose Burrows' hypothesis. Instead, factors such as heightened levels of interspecific competition are likely to have contributed to the wild dog disappearance and subsequent avoidance of the Serengeti plains. Handling and radio telemetry are invaluable when studying elusive endangered species, yielding information pertinent to their conservation and management, and had no effect on Serengeti wild dog survival

Evaluating the use of local ecological knowledge (LEK) in determining habitat preference and occurrence of multiple large carnivores

Understanding habitat preferences and distribution of threatened species is a cornerstone of conservation, however many of the techniques available can be resource intensive. One cost-effective method is by collecting information on species presence and absence from people who regularly interact with the area of interest, also known as Local Ecological Knowledge (LEK). However, the reliability of this type of data has been questioned, especially when there is a possibility that the focal species is being misidentified or their presence misreported. This can introduce false negatives, when a species is present but has not been reported, and false positives, when the species has been reported but is not present. These biases are not always accounted for which can result in the under- or overestimation of species presence. To better understand the reliability of LEK data, we compared the outputs of five different analytical techniques to that of a more widely accepted approach, resource selection functions (RSF), using GPS-collar data from three different carnivore species (African lion Panthera leo, cheetah Acinonyx jubatus and African wild dog Lycaon pictus). Hierarchical models which accounted for the possibilities of both false negatives and false positives most closely matched that of the RSFs, especially for the two rarer species; African wild dog and cheetah. Our results show that when both false negatives and false positives are accounted for that LEK can be used as a rapid and cost-efficient tool for assessing threatened species which can be adopted into practical conservation project

Insights into long-distance dispersal by African wild dogs in East Africa

No abstract available