30 research outputs found
Bovine Tuberculosis at the Wildlife-Livestock-Human Interface in Hamer Woreda, South Omo, Southern Ethiopia
Bovine tuberculosis (BTB) is endemic in cattle in the Ethiopian Highlands but no studies have been done so far in pastoralists in South Omo. This study assessed the prevalence of bovine tuberculosis (BTB) at an intensive interface of livestock, wildlife and pastoralists in Hamer Woreda (South Omo), Ethiopia. A cross-sectional survey including a comparative intradermal skin testing (CIDT) was conducted in 499 zebu cattle and 186 goats in 12 settlements. Sputum samples from 26 symptomatic livestock owners were cultured for TB. Fifty-one wildlife samples from 13 different species were also collected in the same area and tested with serological (lateral flow assay) and bacteriological (culture of lymph nodes) techniques. Individual BTB prevalence in cattle was 0.8% (CI: 0.3%–2%) with the >4 mm cut-off and 3.4% (CI: 2.1%–5.4%) with the >2 mm cut-off. Herd prevalence was 33.3% and 83% when using the >4 and the >2 mm cut-off respectively. There was no correlation between age, sex, body condition and positive reactors upon univariate analysis. None of the goats were reactors for BTB. Acid fast bacilli (AFB) were detected in 50% of the wildlife cultures, 79.2% of which were identified as Mycobacterium terrae complex. No M. bovis was detected. Twenty-seven percent of tested wildlife were sero-positive. Four sputum cultures (15.4%) yielded AFB positive colonies among which one was M. tuberculosis and 3 non-tuberculous mycobacteria (NTM). The prevalence of M. avium-complex (MAC) was 4.2% in wildlife, 2.5% in cattle and 0.5% in goats. In conclusion, individual BTB prevalence was low, but herd prevalence high in cattle and BTB was not detected in goats, wildlife and humans despite an intensive contact interface. On the contrary, NTMs were highly prevalent and some Mycobacterium spp were more prevalent in specific species. The role of NTMs in livestock and co-infection with BTB need further research
The Short-Term Effects of a Routine Poisoning Campaign on the Movements and Detectability of a Social Top-Predator.
Top-predators can be important components of resilient ecosystems, but they are still controlled in many places to mitigate a variety of economic, environmental and/or social impacts. Lethal control is often achieved through the broadscale application of poisoned baits. Understanding the direct and indirect effects of such lethal control on subsequent movements and behaviour of survivors is an important pre-requisite for interpreting the efficacy and ecological outcomes of top predator control. In this study, we use GPS tracking collars to investigate the fine-scale and short-term movements of dingoes (Canis lupus dingo and other wild dogs) in response to a routine poison-baiting program as an example of how a common, social top-predator can respond (behaviourally) to moderate levels of population reduction. We found no consistent control-induced differences in home range size or location, daily distance travelled, speed of travel, temporal activity patterns or road/trail usage for the seven surviving dingoeswemonitored immediately before and after a typical lethal control event. These data suggest that the spatial behaviour of surviving dingoes was not altered in ways likely to affect their detectability, and if control-induced changes in dingoes\u27 ecological function did occur, these may not be related to altered spatial behaviour or movement patterns
Enhancement of local species richness in tundra by seed dispersal through guts of muskox and barnacle goose
The potential contribution of vertebrate-mediated seed rain to the maintenance of plant community richness in a High Arctic ecosystem was investigated. We analysed viable seed content in dung of the four numerically most important terrestrial vertebrates in Northeast Greenland, viz. muskox (Ovibos moschatus), barnacle goose (Branta leucopsis), arctic fox (Alopex lagopus) and arctic hare (Lepus arcticus). High numbers of plant propagules were found in the dung of muskox and barnacle goose. Seeds of many plant species were found in the faeces of one vertebrate species only. Propagule composition in barnacle goose droppings was relatively uniform over samples, with high abundance of the nutritious bulbils of Polygonum viviparum (Bistorta vivipara), suggesting that geese have narrow habitat preference and feed selectively. Propagule composition in muskox dung was diverse and heterogeneous among samples, suggesting generalist food selection and haphazard ingestion of plant propagules with foliage. Species composition of plant propagules in dung samples was different from species composition of the receiving plant communities (in terms of Sørensen and Czekanowski dissimilarity indices) and dung deposition, especially by muskox, often brought new species to the receiving community. The results suggest that endozoochorous propagule dispersal in the Arctic has a great potential in the generation and maintenance of local species richness, albeit being little specialized. It is further suggested that endozoochory is an important means of long-distance dispersal, and hence plant migration in response to climate change