Browsing by Author "Werema, Chacha"

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    The altitudinal and seasonal use of riverine forests by birds in the uluguru mountains, Tanzania
    (Unversity of Dar es Salaam, 2007) Werema, Chacha
    Seasonal and altitudinal distribution of birds was studied between May - 2005 to July 2006 at five altitudes (300, 600, 900, 1200 and 1500 m above sea level) along a riverine forest in Uluguru Mountains, Tanzania. The study aimed at examining the influence of seasons on bird abundant and diversity, and on the relative abundance of birds in different feeding guilds in the riverine vegetation, along the elevation gradient. Furthemiore, the study examined whether forest dependent species were using the riverine forest in both seasons.With the use of mist netting and ringing (a total of 73,440 metre-net hrs), 150 one- hour Timed Species Counts and general field observations, 128 species in 42 families and 11 Orders were identified in this study- of these 58.9% were forest dependent species which at each altitude sampled, were more numerous than non- forest species. Species richnns decreased with increasing elevation. Some bird species, particularly forest dependent ones, moved down to lower altitudes along the riverine forestt during the cold season and during the hot season they migrated to higher altitude forest. The seasonal and altitudinal movements were revealed by ringing recaptures at different altitudes. Due to the presence of seasonal migrants and threatened species during the cold season at low elevations, and the intra-African migrants in the Ulugurus, the study recommends the need for a strict protection and maintenance of the forest along the entire altitudinal gradient, not only in the Ulugurus but also elsewhere. It further stresses the importance of designing wildlife corridors between forest reserves to permit seasonal vertical altitudinal movements of wildlife as well as dispersal into areas of similar altitude.
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    Altitudinal migration of birds in the Uluguru mountains, Tanzania: effects of forest fragmentation, altitude, fire, arthropod food and habitat structure
    (University of Dar es Salaam, 2015) Werema, Chacha
    A study was conducted to assess the effects of forest fragmentation, altitude, seasons, fire, vegetation structure and distance from the source habitat on altitudinal migration of birds at the lower altitude forest fragments and forest edges between 180 – 1300 m above sea level in the Uluguru Mountains, Tanzania. This was conducted using mist netting augmented by audio-visual observations during the cold and hot seasons between 2010 and 2013. Twenty one species, all of them forest dependent had higher abundances during the cold season than in the hot season at most of the study sites. There was no significant relationship between area of the forest fragement and the number of species of altitudinal migrants. The abundances and species diversities of altitudinal migrants were higher during the cold season than in the hot season. Forest fragments located at relatively higher altitudes close to the source habitat, the Uluguru Nature Reserve, had more species, higher abundances and diversities of altitudinal migrants than in the relatively lower altitude forest fragments. Density of trees was positively correlated with the number of species and diversity of altitudinal migrants. Fire negatively affected the abundance of the migrants suggesting that burning of forests can lead to loss of some bird species and restricted use of lower altitude forests by some altitudinal migrants. Due to the isolation of the forest fragments studied and possible inhibition of movements of some of the altitudinal migrants at forest edges, the results of this study have implications for conservation; corridors linking higher with lower altitude forests are needed and further threats to the forest such as fragmentation, creation of forest edges and fires should be reduced