Browsing by Author "Rija, Alfan A."

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Human-induced disturbances influence on bird communities of coastal forests in eastern Tanzania
(2013) Hassan, Shombe N.; Salum, Amina R.; Rija, Alfan A.; Modest, Robert; Kideghesho, Jafari R.; Malata, Pius F.
Aims: To assess the influence of human-induced disturbances on bird communities. Study Design: Longitudinal study. Place and Duration of Study: Four forests; - Kion/Zaraninge, Kwamsisi/Kwahatibu, Msumbugwe and Gendagenda in Pangani–Saadani ecosystem, from October 2010 to January 2011. Methodology: Eight permanent transects, each 500 m long stratified into forest core and forest edge habitats were used in each forest to identify types and quantify levels of human-induced disturbances, determine bird species composition, diversity and richness, and abundance. Therefore three circular plots, each 20 m radius were allocated at beginning, middle and end of each transect. The level of disturbance was assessed using four disturbance indicators; tree lopping, human trails, Pit-sawing and animal snaring while bird species were identified by sight and call. One-way Analysis of Variance was used to test for differences in bird abundance between forests. Moreover, Shannon-Wiener Diversity Index (H’) was calculated for each forest to assess species diversity and evenness, and Bray-Curtis Cluster analysis was used to determine similarity in bird species composition between the forests. Results: A total of 564 individuals composed of 88 bird species distributed in ten Orders were recorded. The level of Pit-sawing and lopping differed significantly between forests (P<.05) with Msumbugwe being more disturbed than the rest. Bird abundance differed significantly between the forests (P<.05) with the highest abundance occurring in Msumbugwe. As expected, species richness and diversity were greater in least disturbed forests-Kiono/Zaraninge and Kwamsisi/Kwahatibu than in the highly disturbed forest, but forest dependent species were not significantly different between the study forests. Apparently, only Pit-sawing was found to correlate with bird abundance (P<.01) whereas similarities in species composition were evident with Kion/Zaraninge and Gendagenda exhibiting much overlap. Conclusion: Increasing forest disturbances seems to negatively impact on distribution of birds thus challenging conservationists to devising sustainable forest management strategies in order to sustain bird diversity and abundances in these unique forests.
Phylogeographic patterns of the greater cane rat (thryonomys swinderianus) populations from Eastern, Western and Southern Africa and implications for wildlife conservation
(Sage Journal, 2023-11-28) Kilwanila, Shadia I.; Lyimo, Charles M.; Rija, Alfan A.; Makundi, Rhodes H.
Background and aim: African Greater Cane (ACG) rat populations are widely distributed across Africa but the ancestral origin of populations inhabiting different geographical regions is unknown. There is currently no information available on the genetic dif- ferentiation of these populations resulting from long-time geographical isolation, environmental and anthropogenic pressures they face in each region. This limits our ability to understand potential speciation processes in AGC and their implications for their conservation and of other small wild mammals exposed to similar ecological conditions in the savannah biomes in Africa. Methods: We analyzed mitochondrial genes targeting the D-loop region of AGC samples from two blocks of the Eastern Arc Mountains in Tanzania (eastern), three agro-ecological zones in Ghana (western) and four sites in South Africa (southern) to characterize the phylogeographical patterns of the species. Results: AGC populations from Tanzania revealed higher haplotype diversity than those from the two other régions. Analysis of variance (AMOVA) revealed higher genetic variations within than between populations in all geographic regions. Demographic history analysis revealed a negative and significant Tajima’s D for a single southern African population as well as close relatedness with the Eastern Africa populations, suggesting a common ancestral origin. Conclusion: This is the first study to compare maternal lineages of AGC populations from eastern, western and southern Africa and provides a basis for future genetic studies of the species, its evolutionary ecology and the conservation of these populations across their range. Conservation implications: Evidence of recent population size expansion underpinned by high genetic diversity observed in the Uluguru urban (Tanzania) Guinea savannah (Ghana) and Kwazulu Natal (South Africa) populations suggest that the AGC populations are not currently threatened, consistent with the current IUCN status. Also, the distinct haplotypes observed in each region suggest that the populations can be managed as meta-populations, thus providing opportunities for potential local game-farming programs.
Population dynamics of the multimammate rat (mastomys natalensis) and makundi’s brush fur rat (lophuromys makundii) and their implications in disease persistence in Mbulu District, Tanzania
(Springer Nature Link, 2024-03-06) Kessy, Stella T.; Sabuni, Christopher; Massawe, Apia W.; Makundi, Rhodes; Rija, Alfan A.
Understanding host population dynamics in connection to disease persistence is important for determining the epizootic risks present in plague foci. We used a capture-mark-recapture method to investigate the population dynamics of Mastomys natalensis and Lophuromys makundii in an active plague focus, in Mbulu District, Tanzania. We hypothesized higher abundance in plague-persistent locality and between habits and seasons. We found distinct patterns of abundance in M. natalensis between farm and forest habitats. The abundance was significantly higher in farms in plague persistent than non-plague persistent areas. The dry season showed a significant increase of abundance compared to the long rain season and the short rain season. A significant increase in breeding females was observed in farms in plague persistent than non-plague persistent localities while farms showed a significant decrease compared to forests. Dry season was associated with an increase in breeding females compared to the long rain season and the short rain season. Furthermore, the abundance of L. makundii showed a significant increase in forest in plague persistent than non-plague persistent localities. The abundance increased significantly during the dry season and long rain season compared to the short rain season. The proportion of breeding females was significantly higher in forests in plague persistent than non-plague persistent localities. The breeding females significantly increased during the dry and the short rain season than the long rain season. These findings contribute to our understanding of the ecological factors shaping the population dynamics of these species and their potential roles in plague persistence.
Rodent abundance, diversity and community structure in a bubonic plague endemic area, northern Tanzania
(De Gruyter, 2023-08-07) Kessy, Stella T.; Makundi, Rhodes H.; Sabuni, Christopher; Massawe, Apia W.; Rija, Alfan A.
Rodent-borne diseases such as bubonic plague remain a significant threat to public health in tropical countries. In plague-endemic areas, little information exists on the factors triggering periodic bursts, thus rendering preparedness strategies for preventing the negative impacts of the deadly zoonosis difficult. In this study, we assessed how species richness, diversity, and community structure of rodents are associated with plague persistence in Mbulu District, Tanzania. Rodent data were collected using the removal trapping technique. We captured 610 rodents belonging to 12 species, with Mastomys natalensis recording highest abundance. There was significantly higher abun- dance and species richness in persistent than non-persistent plague locality. Also, house premises recorded significantly lower species richness than farm and forest habitats. Addi- tionally, we found three broad rodent community structures that varied significantly between studied habitat types sug- gesting high rodent populations interaction at fine-scale resource abundance. The high abundance and diversity of plague-susceptible rodent reservoirs suggestively contribute to the plague persistence in the foci. These results may be useful to developing preparedness strategies in these areas to control plague outbreaks.
Wet season bird species richness and diversity along urban-rural gradient in Morogoro municipality and surrounding areas, Tanzania
(Sokoine University of Agriculture (SUA), 2014-06) Rija, Alfan A.; Bugingo, Adili; Said, Abubakari; Mwamende, Kuruthumu A.
This study examined the variation in diversity and distribution of avian species across an urban–rural gradient during the wet season in Morogoro municipality and its surroundings. A total of 2547 individuals comprising 86 species belonging to 11 orders and 37 families were recorded across urban-rural habitats. The highest (65) species richness was recorded in rural zone, followed by suburban zone (56) and Morogoro core urban zone, the lowest (29). Similarly, species diversity was highest in rural zone (H’= 3.107) and lowest in Morogoro core urban (H’= 2.021), suggesting that increasing urbanization is adversely impacting bird communities across the rural-urban stretch. No significant difference in species diversity was detected between rural and sub-urban zones, but relative abundance of birds differed between the zones. Further, diverse bird guilds were recorded varying across the urban-rural gradients indicating the area’s conservation importance. Increasing urban development severs more suitable habitats with dire consequences on the survival of disturbance-sensitive bird species. These results underpin the need for considering integrated avifaunal conservation strategies and are important for planning local avitourism activities and to protect remaining natural habitats in the municipality. Key words: bird guilds; bird richness; species diversity; urban habitats; urbanrural gradients; Morogoro Tanzania