Browsing by Author "Pomeroy, Derek"

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    Birds of isolated small forests in Uganda
    (Journal of East African Ornithology, 2011) Dranzoa, Christine; Williams, Charlie; Pomeroy, Derek
    This study concerns birds recorded from four small forests in Uganda, three of them being naturally isolated and the fourth being a fragment of the once extensive forests of southern Uganda. Whilst the forest interior birds in the natural forest islands might be considered subsets of those found in larger forests, the fact that the species composition in the three naturally isolated patches are almost completely different from each other, and in one case appear to have changed with time, suggests a major element of chance in which species occur where. There is also a strong indication of species turnover amongst the forest interior birds in these forests. The fact that, together and over time these small forests supported 37 forest interior species, suggests that, collectively, small forests (of which there are many in Uganda) do have conservation value. The evidence of species turnover with time, if confirmed, would increase the numbers of species involved and implies that even interior species do sometimes travel significant distances across other habitats.
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    Conservation of vertebrates and plants in Uganda: Identifying Key Biodiversity Areas and other sites of national importance
    (Conservation Science and Practice, 2019) Plumptre, Andrew J.; Ayebare, Sam; Behangana, Mathias; Forrest, Tom G.; Hatanga, Paul; Kabuye, Christine; Kirunda, Ben; Kityo, Robert; Mugabe, Hamlet; Namaganda, Mary; Nampindo, Simon; Nangendo, Grace; Nkuutu, David N.; Pomeroy, Derek; Tushabe, Herbert; Prinsloo, Sarah
    Uganda is one of the most species rich countries in Africa because of the presence of several major biomes. However, it is also a country that has lost much of its natural habitat to agriculture. Uganda is a country that has been better surveyed for its biodiversity than many African countries, but despite this, there has not been a comprehensive analysis of the critical sites that contribute to biodiversity conservation at a global, as well as at a national level. We here present such an assessment using mammals, birds, reptiles, amphibians, and plants as surrogate taxa. We identified 36 terrestrial sites that are of sufficient global importance to qualify as Key Biodiversity Areas (KBAs), using the Global Standard for the Identification of KBAs, which complement an additional nine freshwater sites. National red listing of species and ecosystems was used to identify sites of national importance for conservation. We employ a conservation planning approach using Marxan to identify the minimum set of sites needed to conserve all the globally and nationally threatened species and nationally threatened habitats in Uganda. The findings show that most of the remaining natural habitat in Uganda is important for the conservation of globally and nationally threatened species and threatened habitat. Large areas of irreplaceable habitat occur outside protected areas, although more extensive surveys of these areas would likely reduce the area that is irreplaceable.
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    The Forest Birds of Kenya and Uganda
    (Journal of East African Natural History, 1996) Leon, Bennun; Dranzoa, Christine; Pomeroy, Derek
    Robust and rapid ways of assessing and monitoring forest biodiversity are increasingly necessary. To this end, we present a classification of forest birds in Kenya and Uganda into three simple categories: forest-specialists (FF species), forest generalists (F species) and forest visitors (f species). FF and F species, but not f species, are dependent on forests. Out of 479 forest birds in the two countries, 214 are FF, 156 F and 109 f species. Forest-dependent birds, and particularly forest specialists, are less widespread than forest visitors. Uganda has 420 forest birds compared to Kenya's 335, and a higher proportion of forest specialists: this reflects differences in forest structure and biogeography, rather than the area of natural forest. Using this classification allows species lists and densities to be interpreted more meaningfully. The number of FF species is an initial measure of a forest's relative conservation importance, while the proportion of FF, F and f species and their relative abundance will shift according to changes in forest structure.
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    Methods of studying the distribution, diversity and abundance of birds in East Africa—some quantitative approaches
    (African Journal of Ecology, 1997) Pomeroy, Derek; Dranzoa, Christine
    In this paper we compare the use of transect counts with a simpler method of investigating bird diversity and numbers, particularly in terrestrial habitats, both natural and non-natural. Transect Counts (TCs) have long been widely used, whereas Timed Species Counts (TSCs), which estimate relative abundance, are comparatively untried. We find that TSCs give results which are comparable to those from TCs in most respects, except that they can only be used indirectly for estimating population densities, and they give different measures of diversity. However, TSCs generate data on many more species much faster than do TCs and are therefore more cost-effective in most situations. In particular, TSCs are useful for community studies. We show, for example, that in natural habitats bird populations are positively correlated with the amount of woody vegetation, but not with rainfall. Diversity too increases with woody vegetation. Because TSCs are simple, more of them can be made for a given input of time, and hence more distributional data are obtained as an additional benefit.
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    A Nationwide Assessment of the Biodiversity Value of Uganda’s Important Bird Areas Network
    (Conservation Biology, 2006) Tushabe, Herbert; Kalema, James; Byaruhanga, Achilles; Asasira, Josephine; Ssegawa, Paul; Balmford, Andrew; Davenport, Tim; Fjeldsa, Jon; Friis, Ib; Pain, Deborah; Pomeroy, Derek; Williams, Paul; Williams, Charles
    BirdLife International’s Important Bird Areas (IBA) program is the most developed global system for identifying sites of conservation priority. There have been few assessments, however, of the conservation value of IBAs for nonavian taxa.We combined past data with extensive new survey results for Uganda’s IBAs in the most comprehensive assessment to date of the wider biodiversity value of a tropical country’s IBA network. The combined data set included more than 35,000 site × species records for birds, butterflies, and woody plants at 86 Ugandan sites (23,400 km2), including 29 of the country’s 30 IBAs, with data on additional taxa for many sites. Uganda’s IBAs contained at least 70% of the country’s butterfly and woody plant species, 86% of its dragonflies and 97% of its birds. They also included 21 of Uganda’s 22 major vegetation types. For butterflies, dragonflies, and some families of plants assessed, species of high conservation concern were well represented (less so for the latter). The IBAs successfully represented wider biodiversity largely because many have distinctive avifaunas and, as shown by high cross-taxon congruence in complementarity, such sites tended to be distinctive for other groups too. Cross-taxon congruence in overall species richness was weaker and mainly associated with differences in site size. When compared with alternative sets of sites selected using complementarity-based, area-based, or random site-selection algorithms, the IBA network was efficient in terms of the number of sites required to represent species but inefficient in terms of total area. This was mainly because IBA selection considers factors other than area, however, which probably improves both the cost-effectiveness of the network and the persistence of represented species.