1,720,977 research outputs found
Seasonal abundance and distribution of Red-capped Robin Chat Cossypha natalensis in the Eastern Arc Mountains, Tanzania
No full textIn Africa, the migratory status of the Red-capped Robin Chat Cossypha natalensis is still not well understood. In some areas, this species has been regarded as either a full or a partial migrant, whereas in other parts of its range, it has been considered as a resident. Here I used my own data and a review of the literature on this species, to assess whether it shows seasonal abundance and distribution in the Eastern Arc Mountains, Tanzania. In order to confirm any partial migration of the Red-capped Robin Chat, I assess its seasonal abundance with those of the Little Greenbul Andropadus virens, an altitudinal migrant, and Grey-backed Camaroptera Camaroptera brachyura, a resident. Results show that the Red-capped Robin Chat is possibly a partial migrant in the Eastern Arc Mountains, being more abundant during the hot season than in the cold season.
French Title: Abondance saisonnière et répartition du Cossyphe à Calotte Rousse Cossypha natalensis dans les montagnes de l’Arc oriental, Tanzanie
En Afrique, le statut migratoire du Cossyphe à Calotte Rousse Cossypha natalensis n’est pas encore bien compris. Dans certaines régions, cette espèce a été considérée comme migratrice totale ou partielle, tandis que dans d’autres parties de son aire de répartition, elle a été considérée comme sédentaire. Ici, j’utilise mes propres données et une revue de la littérature sur cette espèce, pour évaluer si elle présente une abondance et une distribution saisonnières dans les montagnes de l’Arc oriental, en Tanzanie. Pour confirmer toute migration partielle du Cossyphe à Calotte Rousse, j’évalue son abondance saisonnière avec celles du Bulbul vert Andropadus virens, un migrateur altitudinal, et du Camaroptère à tête grise Camaroptera brachyura, un sédentaire. Les résultats montrent que le Cossyphe à Calotte Rousse est peut-être un migrant partiel dans les montagnes de l’Arc oriental, étant plus abondant pendant la saison chaude que pendant la saison froide.
Keywords: abundance, partial migration, season
Seasonal elevational movements of Eastern Olive Sunbird Cyanomitra olivacea in the Uluguru Mountains, Tanzania
No full textLittle is known about the seasonal elevational movements for most tropical avifauna species. Seasonal elevational movements of the Eastern Olive Sunbird Cyanomitra olivacea were studied along an elevational gradient from 600 to 1 500 m above sea level in the Uluguru Mountains, Tanzania, between May 2005 and February 2006. The recapture of ringed individuals along an elevational gradient across seasons provided evidence for the seasonal elevational movement of the Eastern Olive Sunbird in the Uluguru Mountains and the first documented evidence for this species in the Eastern Arc Mountains as a whole. Due to forest fragmentation and lack of corridors connecting high- and low-altitude forests in the Uluguru Mountains, the results have implications for conservation of the forest along the entire elevational gradient as well as for other forest bird species that have been documented to make seasonal elevational movements in the Uluguru Mountains and the entire Eastern Arc Mountains.Keywords: abundance, Eastern Arc Mountains, elevation movement, hot and cold seasons, recapture, ringing, Uluguru Mountain
The avifauna of a naturally regenerating secondary forest, Pangani, North-Eastern Tanzania
No full textAs humans modify native ecosystems with increasing frequency, natural habitats including forests are lost. Under such circumstances, secondary forests can increasingly be important to conservation of biodiversity at landscape scales. However, in East Africa, little is known about avian community composition in regenerating secondary forests. In this study, avian diversity of a regenerating secondary forest was assessed in Pangani, northeastern Tanzania, using point counts. Sixty point counts were conducted for a duration of 12 days in about 90 ha of the regenerating secondary forest. Thirty species were found to utilise the regenerating secondary forest, of which 12 are categorized as forest-dependent species, and 12 were forest visitors. Using the same sampling effort in the adjoining riverine forest, there were 42 bird species, of which 11 and 13 were forest-dependent species and forest visitors, respectively. These results suggest that the regenerating secondary forest provided a habitat for a number of bird species including forest-dependent species and a few intra-African migrants, and it is thus of conservation value, at least at a local scale. Maintaining such regenerating secondary forests can provide greater landscape connectivity for the survival and, possibly, dispersal of birds
Preliminary comparison of birds inhabiting exotic Acacia and native bushland habitats in semi-arid east-central Tanzania
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Avian Use of Habitat Patches Dominated by Exotic Leucaena leucocephala or Native Tree Species in Urban Dar es Salaam, Tanzania
Get PDFThere has been an incursion of an exotic Leucaena leucocephala in disturbed areas and into habitat patches of native tree species in some areas in Tanzania. However, the impacts of this exotic tree on native biodiversity are not well understood. We assessed bird use of habitat patches dominated by L. leucocephala in comparison to patches of native tree species at the University of Dar es Salaam main campus, Tanzania, by comparing bird species richness, abundance and diversity using mist netting. Based on the same mist netting efforts in each habitat patch type, patches of native trees had significantly higher overall diversity (t = 1.999, df = 293.64, p < 0.05) and abundance (χ2 = 40.525, df = 1, p < 0.001) of birds than those dominated by the exotic L. leucocephala and significantly greater abundance of forest-dependent species (χ2 = 10.938, df = 1, p < 0.001) and forest visitors (χ2 = 15.258, df = 1, p < 0.001). The similarity in bird species between the two habitats was 0.658 indicating that many bird species occurred in both habitat types. The lower diversity and overall abundance of birds in the patches dominated by the exotic plant suggest that it does not provide appropriate habitat for many bird species, and further spread of this exotic will be detrimental to the local avifauna.
Keywords: Birds, diversity, native tree species, exotic tree species, Leucaena leucocephala
Detection and management of lameness in dairy cattle in New Zealand and Tanzania : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Veterinary Science at Massey University Te Kunenga Ki Pūrehuroa, University of New Zealand, School of Veterinary Science, Manawatu
No full textAlongside mastitis and infertility, lameness is one of the key animal health challenges on dairy farms. Lameness is particularly challenging due to the complex nature of its aetiopathogenesis and its multiple risk factors. Early detection combined with effective treatment, management and prevention are integral approaches to reducing the impact of lameness on dairy farms, improving productivity, and enhancing animal health and welfare. This thesis focused on improving detection and improved management. Visual locomotion scoring (LS) is currently the most widely used system for detecting lameness worldwide but has attributes that limit its usefulness and application. The first part of this thesis presents three studies looking at alternatives to LS: infrared thermography (IRT) and in-parlour scoring (IPS). IRT was compared to LS in both New Zealand and Tanzania, while IPS was tested in New Zealand alone. Both IRT and IPS proved to be useful alternatives to LS, but further research on more farms across more countries is required before they can replace LS for lameness detection on dairy farms. The second part of the thesis evaluates the response to a three timepoint regime of prophylactic hoof trimming (dry-off, early lactation, and end of lactation) on; 1) lameness incidence and time from calving to increased locomotion score, and 2) the distance from the external claw sole surface to the distal phalanx (DDP), and how this relates to lameness risk. On the study farm, prophylactic hoof trimming did not decrease lameness incidence or time to clinical lameness (locomotion scores ≥2). However, it did increase the interval from calving to an observable change in gait (locomotion scores ≥1). In regard to DDP, the study showed that DDP was not affected by trimming and that changes in DDP did not affect the hazard of increased locomotion score, i.e. either locomotion scores ≥1 or locomotion scores ≥2.
Keywords: lameness; locomotion scoring; infrared thermography; in-parlour scoring; prophylactic hoof trimming; dairy cattle; pasture-based system; tropica
Understorey Bird Communities 8 and 18 Years after River Diversion in Kihansi Gorge, Udzungwa Mountains in the Eastern Arc Mountains, Tanzania
Get PDFOn the most south-western slopes of the Udzungwa Mountains in Tanzania lies Kihansi River. The river was diverted underground in 2000 to run electric turbines for electricity generation. Using mist netting, pre-diversion (in 1998 and 1999) and short term post-diversion (in 2001) effects of the river diversion on understorey birds were undertaken before and year after river diversion, respectively. Intermediate and long-term effects of river diversion on understorey birds at the same transects are non-existent. In September 2008 and August and September 2018, using mist nets, birds were surveyed at the same transects to assess whether or not there have been changes in avian community structure, abundance and diversity eight and 18 years after the river was diverted. Results suggest that there have been no significant changes in pre- diversion and eight and 18Keywords: Avian community composition; Kihansi River; Mist netting; River diversion; Species diversity; Understorey forest bird
Effect of habitat fragmentation on diversity and abundance of nesting birds in an urban landscape: the case of Mwalimu Nyerere Campus thickets, University of Dar es Salaam, Tanzania
Get PDFLittle is known of the nesting bird species in most of urban areas of East Africa. An investigation was made of the occurrence of breeding bird species in the fragmented thickets found in the Mwalimu Nyerere Campus of the University of Dar es Salaam, in the City of Dar es Salaam. The study examined how habitat fragmentation affects nesting bird species richness and diversity in the thickets. Systematic physical nest searches of breeding birds were conducted in the fragmented thickets. Searches were conducted in transects and they included inspecting vegetation, bare ground, cavities, stream (river) banks and other suitable nesting locations for the presence of active nests. Numbers and diversity of nesting bird species increased with fragment size which suggest that most nesting birds avoid smaller fragments and that reductions in size of habitat might negatively affect majority of the nesting bird species. For continued conservation of birds, protection of the remaining thicket fragments on the campus is recommended.Keywords: fragmentation, nesting birds, thickets, campus of the University of Dar es Salaam, nest species diversit
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