During 2007–2009 we conducted a survey of attacks by wild carnivores on the livestock of the Maasai and Sonjo tribes in the eastern Serengeti ecosystem of northern Tanzania. Local enumerators ...systematically recorded incidents of carnivore predation on livestock and their data were quantified by us, with the aid of District Game Officers or trusted local people. The annual rate of attack by African wild dogs Lycaon pictus was significantly higher (1.42 animals per 1,000 livestock) in the Sonjo tribal area than in the Maasai tribal area (0.72 animals per 1,000 livestock). In the Maasai tribal area there was a significant amount of predation by leopards Panthera pardus and spotted hyaenas Crocuta crocuta. In both tribal areas sheep Ovis aries and goats Capra aegagrus hircus were subject to predation more frequently than cattle. Attacks on livestock by wild dogs occurred most frequently in the afternoon and evening, whereas other carnivores generally attacked livestock at night. Sheep and goats were most frequently attacked by most carnivores during the long rainy season. Cattle Bos primigenius were most frequently attacked by wild dogs and leopards during the long dry season and by lions Panthera leo during the long rainy season, whereas spotted hyaenas killed cattle most frequently during the short rainy season.
In an opinion letter¿¿to Nature (September 2010), Dobson et al. (2010) oppose the planned road through northern Tanzania that crosses Serengeti National Park (SNP). They contend that the road will ...jeopardize the Serengeti ecosystem by interrupting the wildebeest (Connochaetes taurinus) migratory corridor. This opinion is supported by other scientists using mathematical models (Holdo et al. 2011). However, all arguments presented against the project have been questioned (Homewood et al. 2010). As has often been the case in the conservation of African natural resources, some scientists present views that do not account for other key components of conservation: economic growth, reduction of poverty, improvement of quality of life, and social well-being. As scientists working in Serengeti, we believe that the published reports about the Serengeti road mislead the world about its potential effects on the ecosystem.
Summary
Mycobacterium bovis, the causative agent of bovine tuberculosis (bTB), is a multihost pathogen of public health and veterinary importance. We characterized the M. bovis isolated at the ...human–livestock–wildlife interface of the Serengeti ecosystem to determine the epidemiology and risk of cross‐species transmission between interacting hosts species. DNA was extracted from mycobacterial cultures obtained from sputum samples of 472 tuberculosis (TB) suspected patients and tissue samples from 606 livestock and wild animal species. M. bovis isolates were characterized using spoligotyping and Mycobacterial Interspersed Repetitive Units‐Variable Tandem Repeats (MIRU‐VNTR) on 24 loci. Only 5 M. bovis were isolated from the cultured samples. Spoligotyping results revealed that three M. bovis isolates from two buffaloes (Syncerus caffer) and 1 African civet (Civettictis civetta) belonged to SB0133 spoligotype. The two novel strains (AR1 and AR2) assigned as spoligotype SB2290 and SB2289, respectively, were identified from indigenous cattle (Bos indicus). No M. bovis was detected from patients with clinical signs consistent with TB. Of the 606 animal tissue specimens and sputa of 472 TB‐suspected patients 43 (7.09%) and 12 (2.9%), respectively, yielded non‐tuberculous mycobacteria (NTM), of which 20 isolates were M. intracellulare. No M. avium was identified. M. bovis isolates from wildlife had 45.2% and 96.8% spoligotype pattern agreement with AR1 and AR2 strains, respectively. This finding indicates that bTB infections in wild animals and cattle were epidemiologically related. Of the 24 MIRU‐VNTR loci, QUB 11b showed the highest discrimination among the M. bovis strains. The novel strains obtained in this study have not been previously reported in the area, but no clear evidence for recent cross‐species transmission of M. bovis was found between human, livestock and wild animals.
The authors describe genital alterations and detailed histologic findings in baboons naturally infected with Treponema pallidum. The disease causes moderate to severe genital ulcerations in a ...population of olive baboons (Papio hamadryas anubis) at Lake Manyara National Park in Tanzania. In a field survey in 2007, 63 individuals of all age classes, both sexes, and different grades of infection were chemically immobilized and sampled. Histology and molecular biological tests were used to detect and identify the organism responsible: a strain similar to T pallidum ssp pertenue, the cause of yaws in humans. Although treponemal infections are not a new phenomenon in nonhuman primates, the infection described here appears to be strictly associated with the anogenital region and results in tissue alterations matching those found in human syphilis infections (caused by T pallidum ssp pallidum), despite the causative pathogen’s greater genetic similarity to human yaws-causing strains.
Wildlife species exposed to habitat fragmentation are often in need of a conservation effort. The African buffalo (
Syncerus caffer
) is one of the key species in the Serengeti ecosystem as they form ...a large part of the herbivore biomass, providing ecotourism and valuable trophies. The ecosystem is a part of Tanzanias protected areas and is administrated under different management practices. Among these, we have analysed the genetic structure of buffalo (
n
= 68) from the Serengeti National Park (SNP), the Ngorongoro conservation area (NCA) and the Maswa game reserve (MGR). Both the sequence variation in a 493 base pair fragment of the mitochondrial D-loop and the allele frequency-distribution in 15 microsatellites suggest genetic structuring of the buffalo populations within the ecosystem. Both the allele frequency-distribution and the amount of genetic variation were high and similar in SNP and MGR, suggesting a high degree of gene flow between these locations. By comparison, the NCA buffaloes had significantly lower genetic variation and were genetically differentiated from SNP and MGR. Approximate Bayesian computation estimates suggest that the observed genetic structure is of a recent origin, indicating that the recent increases in developmental activity in the region may have influenced the genetic structure of the buffalo within the Serengeti ecosystem.
We tested wildlife inhabiting areas near domestic livestock, pastures, and water sources in the Ngorongoro district in the Serengeti ecosystem of northern Tanzania and found 63% seropositivity for ...peste des petits ruminants virus. Sequencing of the viral genome from sick sheep in the area confirmed lineage II virus circulation.
In a population of spotted hyenas (
Crocuta crocuta) monitored between 1996 and 2005 in the Ngorongoro Crater, Tanzania, 16 individuals from five of eight social groups displayed clinical signs of an ...infection, including severe unilateral swelling of the head followed by abscess formation at the mandibular angle, respiratory distress, mild ataxia, and lethargy. Two (12.5%) of these 16 individuals died within days of developing signs. Clinical signs in hyenas were first noted in 2001, and most cases occurred between September 2002 and February 2003, suggesting an outbreak of infection during this period. Histopathological examination of internal organs from one hyena that died with signs revealed morphological changes consistent with severe bacterial infection. Phenotypic examination and phylogenetic analysis of the 16S rRNA gene of the causative agent of infection revealed a Lancefield group C
Streptococcus with a high level of homology to
S. equi subsp.
ruminatorum, a subspecies of
S. equi recently described in domestic sheep (
Ovis aries) and goats (
Capra hircus) with mastitis in Spain. Strains similar to this bacterium were also isolated from two hyenas without obvious clinical signs, suggesting that hyenas may be ‘carriers’ of this bacterium, and from a sympatric Burchell's zebra (
Equus burchelli), a herbivore species often consumed by hyenas. To our knowledge this is the first report of a
Streptococcus infection in these two wildlife species. The high genetic similarity between the hyena and zebra isolates indicates that inter-specific transmission may occur, possibly when hyenas consume infected zebra carcasses.
Wild mammals in Africa mostly have high levels of innate resistance to haemoparasites and the tick vectors that transmit them. Occasionally though, biotic and abiotic factors combine to alter this ...relationship and tick-borne disease is diagnosed in wildlife. We postulate an inter-relationship between anthropogenic and natural factors that resulted in wildlife mortality, attributable to disease transmission associated with a gradual build-up of large numbers of ticks. Suppression of grassland fire for 27 years in a distinct ecological unit promoted a gradual expansion of areas covered by tall grass. Changes in composition of the pasture led to improved tick survival, which was further boosted by the availability of increasing numbers of a coarse-grazing species and preferred tick host, African buffalo. Alternating climatic cycles then appeared to precipitate an outbreak of tick-borne haemolytic disease by subjecting ticks and their herbivore hosts to ideal conditions (in wet years) followed by starvation and immune suppression (in dry years). Evidence supporting the hypothesis was gathered retrospectively in the present study through systematic sampling of tick density and correlating life stages of ticks to season, grass species and height of the grass sward. Tick host preference was noted by collection from immobilized wild animals and sympatric livestock. A long series of census data confirmed the changing composition of resident wild herbivores in the Ngorongoro Crater. To reduce the tick challenge, prescribed burning of the crater grassland was reintroduced; tick numbers fell rapidly and three years of subsequent monitoring confirmed the success of this strategy.
Equid herpesvirus 9 (EHV-9) was isolated from a herd of Thomson's gazelles affected by encephalitis. The natural host of EHV-9 is unknown, but zebras are suspected to be the source of infection in ...gazelles. To prove this hypothesis, we analyzed 43 sera from Burchell's zebras (Equus burchelli) and 21 Thomson's gazelles (Gazella thomsoni) from the Serengeti ecosystem for neutralizing antibodies. Seven zebra sera were positive for EHV-1, EHV-9 and EHV-1 from Grevy's zebra strains T965 and T616. The trigeminal ganglia of 17 other Burchell's zebras and one Thomson's gazelle were tested by EHV-9 gB and EHV-1 ICP0-specific nested polymerase chain reaction (PCR). PCR sequencing confirmed that one zebra ganglion was positive for EHV-9. These results suggest that the Burchell's zebras were exposed to EHV-9 and latently infected.
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