Browsing by Author "Rija, A. A."

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Activity patterns and fine-scale resource partitioning in the gregarious Kihansi spray toad Nectophrynoides asperginis in captivity
(Wiley & Sons) Rija, A. A.; Goboro, E. M.; Mwamende, K. A.; Saidi, A.; Kohi, E. M.; Shombe, H. N.
Activity patterns and fine-scale resource partitioning in the gregarious Kihansi spray toad Nectophrynoides asperginis in captivity
(Wiley & Sons, 2014-08-01) Rija, A. A.; Goboro, E. M.; Mwamende, K. A.; Saidi, A.; Kohi, E. M.; Shombe, H. N.
Understanding the behavior of species threatened with extinction is important for conservation planning and for solving problems facing species in captivity and the wild. We examined diurnal activity budgets and habitat use of the extinct in the wild Kihansi spray toad to provide insights into ongoing conservation initiatives for this species. Observations on eight target behaviors were made each morning and evening for 14 days, in two subpopulations at Kihansi and University of Dar es Salaam captive breeding centers. There were significantly more bouts of resting than calling, amplexing, hunting, walking, climbing, or feeding. There was no difference in mean time spent in each activity between the two subpopulations. The use of habitat was variable between age classes, subpopulations and sampling time. Young toads spent significantly more time resting at the top of vegetation and on walls while adults rested
Assessment of fire prevalence and reduction strategies in Miombo woodlands of Eastern Tanzania
(African Journals Online) Katani, J. Z.; Madoffe, S.S.; Amanzi, N. S.; Amanzi, N. S.; Rija, A. A.; Midtgaard, F.; Mbeyale, G. E.; Zahabu, E.; Tarimo, B. C.
Assessment of fire prevalence and reduction strategies in Miombo woodlands of Eastern Tanzania
(African Journals Online, 2014-12) Katani, J. Z.; Madoffe, S.S.; Amanzi, N. S.; Amanzi, N. S.; Rija, A. A.; Midtgaard, F.; Mbeyale, G. E.; Zahabu, E.; Tarimo, B. C.
An assessment of the proximate causes, effects and factors contributing to fire prevalence was conducted in three districts covered by miombo woodlands in Eastern Tanzania. Three miombo woodlands under different management regimes and governance structures (central government forest reserve, local government forest reserve and village land forest) each were investigated in Handeni, Kilosa and Kilwa districts. Data were collected from three villages selected in each District through household surveys, Participatory Rural Appraisal (PRA), interviews of key informants and field observations. The analysis of data involved content analysis for documentary materials, descriptive statistical analysis for household surveys and Chi square was used to test whether there were differences in responses of local communities across forest management regimes. Results indicate that the major five human activities contributing to fire prevalence across the miombo woodlands include farm preparation (34.1%), hunting (28.5%), arson (21.5%), livestock grazing (9.3%) and charcoal making (0.7%). The causes were fairly the same across forest management regimes. August, September and October were the peak fire months and they were not influenced by different management regimes but by geographical locations within Eastern Tanzania. Results further show that fires in miombo woodlands usually start inside the woodland (67.2%), around residential area (22.9%) and from farms (9.9%). The origin of fire inside the woodland becomes more serious because it combines the hunting, arson, livestock grazing and charcoal making which are usually done inside the woodland. Chi-square test indicates significant difference on origin of fires across the forest management regimes (χ² = 13.341 and p = 0.031). The local communities acknowledged fires having both positive and negative effects and these effects were the same across the management regimes. Further, across the surveyed villages, strong social ties existed between fires and the daily life of local communities. Poverty, ignorance, weak law enforcement and climatic factors were identified as underlying factors contributing to fire prevalence. Fire incidences are predicted to increase given the increasing climate change. Potential strategies to reduce fires incidence identified were awareness creation, law enforcement, making fire breaks, introduction of alternative income generating activities, and improving agriculture practises. Furthermore, the use of prescribed burning to reduce effects of late fires and developing fire management plans to enhance miombo woodland management are among the strategies worth consideration by the local communities.
Composition and Functional Diversity in Bird Communities in a Protected Humid Coastal Savanna
(Hindawi Publishing Corperation) Rija, A. A.; Mgelwa, A. S.; Modest, R. B.; Shombe, H. N.
Composition and Functional Diversity in Bird Communities in a Protected Humid Coastal Savanna
(Hindawi Publishing Corperation, 2015-04) Rija, A. A.; Mgelwa, A. S.; Modest, R. B.; Shombe, H. N.
Our current understanding of the vertebrate communities of a newly gazetted Tanzanian coastal national park is limited and strongly taxonomically biased towards large mammals. We conducted bird assessments in three sites in Saadani National Park using species lists to analyze some parameters to inform biodiversity conservation in the area. We recorded 3112 individuals in 268 species falling in 66 families, including 2 endangered, 2 vulnerable, and 6 near threatened species. Both species richness and species diversity varied between sites. Species relative abundances were not different between the sites although some functional groups, especially granivores, were more abundant than others. Bird assemblages included 21 forest specialists (FF-species), 35 forest generalists (F-species), and 68 forest visitors (f-species) overlapping among bushland, wooded grassland, grassland, and thickets suggesting presence of important microhabitats for the forest-associated species in this ecosystem. Bird species richness in a feeding guild also showed marked overlap between habitats suggesting availability of rich food resources for the birds. This paper highlights the importance of maintaining a structurally heterogeneous landscape to sustain diverse bird communities in the area.
Developing Fire Reduction Strategy for Miombo Woodlands as a Potential tool for Carbon Storage and Sequestration
(E&D Vision Publishing Ltd) Katani, J. Z.; Modoffe, S.S.; Midtgaard, F.; Rija, A. A.; Amanzi, N. S.; Kilawe, C.J.; Mbeyale, G. E.; Zahabu, E.; Tarimo, B. C.; Silayo, D.S. A.
Developing Fire Reduction Strategy for Miombo Woodlands as a Potential tool for Carbon Storage and Sequestration
(E&D Vision Publishing Ltd, 2016) Katani, J. Z.; Modoffe, S.S.; Midtgaard, F.; Rija, A. A.; Amanzi, N. S.; Kilawe, C.J.; Mbeyale, G. E.; Zahabu, E.; Tarimo, B. C.; Silayo, D.S. A.
World-wide, wildfires cause problems and when uncontrolled or misused they wreak havoc on society and the environment. In Tanzania, fire occurs in most parts of the Miombo woodlands, and some of them cause significant eco-logical and socio-economic impacts. Several efforts have been made in Tanzania to reduce the occurrence of fire in Miombo but their success has been constrained by underfunding and/or lack of proper strategies. Moreover, in many districts of Tanzania there are no apparent solutions to the fire problem, despite years of regulation and attempts to control fire, and in many places fire incidences are actually increasing. Therefore, this study intended to develop a fire management strategy for the Miombo woodland as a tool for climate change mitigation. This study also strived to identify causes, effects and factors contributing to fire prevalence. Spatial and temporal distribution of fires and burnt extents of wooded areas were determined from the Moderate Resolution Imanging Spectroradiometer (MODIS) active fires product and Landsat satellite images for the past 40 years (1972–2012). Vegetation and household surveys were used to capture empirical data on carbon stock and how different burning regimes and forest management scenarios influence carbon sequestration potentials. Furthermore, the role of formal and informal framework for the prevention, control and management of wild fires in the Miombo was determined. Th main output of this study is a proposed fire reduction strategy in Miombo. Th study findings show that, to a wider extent, 1.8 and 2.9 years mean fire return interval persist in western and eastern dry Miombo areas, respectively, burning up to 50.6% of the woodland. These wildfires were largely human-driven and commonly occur in all the villages surveyed whereas the existing local governance structures and institutions suffered from poor coordination, severe underfunding and poor support from the villagers. Torching of forests was largely perpetuated by weak enforcement of laws and regulations, poverty and existing local beliefs. On average, there is an indication that the central government forests have higher stock of carbon than the local government forests and village government forest reserves. However, there was no significant difference in carbon stock between forests experiencing no burning, early burning and late burning. The proposed fire management strategy for Miombo woodlands focused on the promotion of sustainable alternative land preparation methods, improved household income sources and awareness, sustainable land use management and promotion of sustainable charcoal production. The strategy indicates a number of activities to be implemented and actors responsible for each activity.
Emerging issues and challenges in conservation of biodiversity in the rangelands of Tanzania
(Pensoft Publishers) Rija, A. A.; Kideghesho, J. R.; Rija, A. A.; Kideghesho, J. R.; Mwamende, K. A.; Selemani, I.
Emerging issues and challenges in conservation of biodiversity in the rangelands of Tanzania
(Pensoft Publishers, 2013-11-18) Rija, A. A.; Kideghesho, J. R.; Rija, A. A.; Kideghesho, J. R.; Mwamende, K. A.; Selemani, I.
Tanzania rangelands are a stronghold for biodiversity harbouring a variety of animal and plant species of economic, ecological and socio-cultural importance. Efforts to protect these resources against destruction and loss have involved, among other things, setting aside some tracks of land as protected areas in the form of national parks, nature reserves, game reserves, game controlled and wildlife management areas. However, these areas and adjacent lands have long been subjected to a number of emerging issues and challenges, which complicate their management, thus putting the resources at risk of over exploitation and extinction. These issues and challenges include, among other things, government policies, failure of conservation (as a form of land use) to compete effectively with alternative land uses, habitat degradation and blockage of wildlife corridors, overexploitation and illegal resource extraction, wildfires, human population growth, poverty, HIV/AIDS pandemic and human-wildlife conflicts. In this paper, we review the emerging issues and challenges in biodiversity conservation by drawing experience from different parts of Tanzania. The paper is based on the premise that, understanding of the issues and challenges underpinning the rangelands is a crucial step towards setting up of plausible objectives, strategies and plans that will improve and lead to effective management of these areas. We conclude by recommending some proactive measures that may enhance the sustainability of the rangeland resources for the benefit of the current and future generations.
Fire history and management as determinant of patch selection by foraging large mammal herbivores in western Serengeti, Tanzania
(Taylor & Francis) Rija, A. A.; Shombe, H. N.
Floss release, seed fall and germination of Ceiba pentandra in an urban environment
(Scientific Research Publishing) Rija, A. A.; Saidi, A.; Mwita, J.; Mwamende, K. A.
Floss release, seed fall and germination of Ceiba pentandra in an urban environment
(Scientific Research Publishing, 2013-09-25) Rija, A. A.; Saidi, A.; Mwita, J.; Mwamende, K. A.
The tropical forest kapok tree occurs widely in urban environments, dispersing thousands of floss during the fruiting season. However, its seedlings are rarely seen around human settlements, raising questions on what factors might be limiting its recruitment. We examined the pattern of floss release, seed fall post-dispersal and influences of watering frequency on germination of Ceiba pentandra seeds. Evening, overall, was associated with a significantly higher rate and quantity of floss release (p= 0.0001) than were mid-day and morning, correlating well with the speed of wind across the day (rh= 0.666, p= 0.001). Mean dispersal quantity differed significantly between the individual sampled trees, in which the highest dispersal was recorded from trees located in relatively open areas and the lowest was recorded in closed stand trees. Seed fall was higher within 100 m distances than seed fall farther away from dispersing trees, depending on the microsites and weather conditions. Germination started on day 5 onwards and only 15.67% of sown seeds germinated. Watering frequency strongly influenced seed germination while local human activities determined fate of dispersed seeds. We conclude that recruitment of C. pentandra species in the study area may have been limited by environmental and human factors operating at various local and spatial scales.
Incentives for conserving and greening our cities
(Ministry of Natural Resources and Tourism-Tanzania) Rija, A. A.
Incentives for conserving and greening our cities
(Ministry of Natural Resources and Tourism-Tanzania, 2010-11-09) Rija, A. A.
Modeling black rhinoceros (Diceros bicornis) population performance in East Africa: the case of Lake Nakuru National Park, Kenya
Rija, A. A.; Soka, G. E.; Owino, A.
Notes on Feeding Habits of Spider Nephila sp in an Acacia woodland stand, Kenya
(biological research) Rija, A. A.; Mwamende, K. A.; Shombe, H. N.
Population density estimates of some species of wild ungulates in Simanjiro plains, northern Tanzania
(Wiley Online Library) Rija, A. A.; Shombe, H. N.
Population density estimates of some species of wild ungulates in Simanjiro plains, northern Tanzania
(Wiley Online Library, 2011-02-09) Rija, A. A.; Shombe, H. N.
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Preliminary Assessment of Forest Structure, Management and Carbon Stocking in Tanzania Miombo Woodland
(Climate Change Impacts, Mitigation and Adaptation Programme, SUA) Madoffe, S. S.; Rija, A. A.; Midtgaard, F.; Katani, J. Z.; Mbeyale, G. E.; Zahabu, E.; Christopher, B.