PhD Theses

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Browsing PhD Theses by Subject "Amphibians"

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    Ecology and altitudinal distribution of herpetofauna on mount Kilimanjaro, Tanzania
    (University of Dar es Salaam, 2017) Ngalason, Wilirk
    A study on the diversity, habitat use, activity and reproduction of herpetofaunal species with respect to altitude and climatic conditions was conducted on Mt. Kilimanjaro between 2011 and 2012. Standard methods for the study of herpetofaunal species were used. The surveys were conducted along an altitudinal gradient from 1500 m a.s.l. and above during both the dry and the rainy seasons. Twenty-four herpetofaunal species were detected. The diversity of the species declined with an increase in elevation. Sites that were adjacent to each other had greater species similarity than did sites far from one another. Furthermore, species diversity was significantly higher on the leeward than on the windward side, and the number of species varied significantly between different habitat types. Additionally, habitat utilisation by herpetofaunal species varied with elevation. The proportion of diurnal species increased whereas that of nocturnal species decreased with an increase in elevation. Moreover, the proportion of egg-laying (oviparous) species decreased while that of live-bearing (viviparous) species increased with an increase in elevation. The large proportion of species at lower altitudes was seasonal breeders whereas that at higher elevations exhibited extended breeding patterns. The relatively young geological age of the mountain, the decrease in temperature and precipitation with an increase in altitude accompanied by altitudinal zonation of vegetationappeared to be the major determinants of the findings obtained. Future studies are recommended to fill the gaps identified in this study. Additionally, the conservation and management of different habitat types on Mt. Kilimanjaroare recommended for the continued existence of varied herpetofaunalspecies
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    Habitats, distribution and feeding of Amphibians in Zaraninge forest reserve, Tanzania: a case study of the ecology of a community of Amphibians in a coastal forest ecosystem in Bagamoyo district, Tanzania.
    (University of Dar es Salaam, 2001) Msuya, Charles Andekia
    A study on habitats distribution, abundance and prey of the amphibians in Zaraninge Forest Reserve was conducted between March 1994 and December 1996. The major habitat categories in Zaraninge Forest Reserve are forests, woodlands, wetlands and cultivation. Gongo plateau forest, riverine and the depression wetland were identified as the most important areas for the conservation of anurans in Zaraninge. Bucket pitfall traps with drift fences, plots, audio strip transects and visual sampling methods were employed to determine amphibians species composition, habitat occupancy patterns over the dry and wet seasons. Bucket pitfall traps with drift fence were successfully used to detect the direction of movements of the amphibians during breeding migrations and the dispersal of juveniles. The community of amphibians in Zaraninge Forest Reserve is purely anuran, with 2 forest specialist species, 3 aquatic and 25 generalist or savannah species. To the best of my knowledge, the area ranks highest in amphibian species richness fauna in coastal East Africa, but is poor in coastal forest endemic species. Seasonal variation in species distribution and abundance in the habitats was associated with breeding activities and survival from desiccation and predation. Rainfall was an important factor by determining moisture content in the substratum and activities of the anurans. Its pattern determined the longevity of breeding pools and successful recruitment of juveniles and the distance they dispersed from breeding sites. Fire affected the quality of micro-environments outside forest habitat during the dry season and was the primary cause for anurans to take refuge in forest areas during the dry seasons. Food, temperature and humidity were not important environmental factors affecting the distribution and abundance of anurans in the reserve. The study provides baseline information of the group in an Afro-tropical lowland environment.