Although protected areas have been used as principal conservation tools, most of them are suffering from human-induced threats. Consequently, a good understanding of such human-driven threats on biodiversity and identifying early warning systems for habitat change in protected areas is necessary for effective conservation of natural resources. To examine the impact of human disturbance on avifaunal assemblages and to assess the potential application of birds as bioindicators of forest health monitoring in the Afromontane forest of the Bale Mountains of Ethiopia, I recorded birds and habitat variables in three protected and three unprotected forests using a point transect method in 2009 and 2012. The two land use types differ in disturbance levels (higher in the unprotected areas), vegetation structure and bird assemblages. Species richness of entire bird guild, open woodland and open land habitat guilds, granivore and insectivore feeding guilds, and shrub layer and ground layer foraging substrate guilds of birds were significantly higher in the unprotected areas than the protected areas. Abundances of guilds of birds mostly followed a similar trend with species richness. However, densities of overall and forest-specialist bird guilds were higher in the protected area and vice versa for the other guilds. In general, the protected area assemblages were dominated by forest-specialist species, while those of the unprotected areas were dominated by openland and shrubland species. The implication is that disturbance had caused encroachment of non-native species (openland, open woodland and shrub land species) while negatively affecting native species (forest species, particularly tree canopy foragers). These assemblage differences are linked to changes in vegetation structure caused by disturbance. Thus, further forest degradation in the protected area should be avoided in order to maintain native/forest-specialist species. Given the differences in bird assemblages between the two land use types, there is a high likelihood that bioindicator species (i.e. indicator species - those 'characteristic' of a particular habitat - and detector species - those occurring in the different habitats considered but with moderate indication value) can be identified, therefore providing a useful tool to monitor ecosystem health of the forests. Four and nine species were identified as appropriate indicator species (i.e. species with indicator values > 60% and fulfilling biological and niche history criteria used in selection) in the protected and unprotected areas, respectively. In addition, nine species were identified as detectors of habitat change in the protected areas. These bioindicators provide a useful tool for managers of Afromontane forest in the Bale Mountains, as well as similar habitats elsewhere, for long term monitoring of ecosystem health of the forests. / Dissertation (MSc)--University of Pretoria, 2013. / DST/NRF Centre of Excellence / Zoology and Entomology / MSc / Unrestricted

Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2016-03-24T00:16:19Z No. of bitstreams: 1 Dissertacao Andr? Lucas de O. Moreira.pdf: 876287 bytes, checksum: 1ce1050791f2181466341637ebc506c9 (MD5) / Made available in DSpace on 2016-03-24T00:16:19Z (GMT). No. of bitstreams: 1 Dissertacao Andr? Lucas de O. Moreira.pdf: 876287 bytes, checksum: 1ce1050791f2181466341637ebc506c9 (MD5) Previous issue date: 2013-01-31 / Funda??o de Amparo ? Pesquisa do Estado da Bahia - FAPEB / Urbanization is a process responsible for environmental disturbances that occur at various levels, resulting in changing patterns of biodiversity. However, little is known about the resistance, functional diversity and ecological processes that structure communities of birds in urban environments. The present study aimed to investigate the species richness, functional diversity, resistance and ecological process that determines the assembly of communities and define diversity patterns of six bird communities in urban environment. This study was conducted in six different sizes with green areas and inserted into the urban matrix, in the city of Aracaju, Sergipe, northeastern Brazil. The tree density of the study areas were measured by counting the trees with a diameter greater than 50 mm to investigate its relation to bird diversity. The richness, composition and frequency of occurrence of the species were investigated between September 2011 and July 2012, using the method lists Mackinnon, adapted to 10 species. The sampling effort resulted in a total of 720 listings - 120 lists each area. 82 species of birds were observed and divided into 36 families. The richness of bird species increased due to the increased size of woodlands. The increase in tree density was also associated with increased species richness of birds. However, the functional richness (Fric) decreased with the increase in species richness. This study demonstrates that communities have the richest bird species with similar functions. They are functionally redundant and more resistant to environmental disturbances. It is also possible that the homogenization of bird communities in urban environments occurs through the filtering process of habitat that should structure these communities on a local scale. The environmental filters should favor the occurrence of species with certain functional characteristics and may limit the occurrence of species with distinct characteristics. / A urbaniza??o ? um processo respons?vel por dist?rbios ambientais que ocorrem em v?rios n?veis, resultando em altera??es dos padr?es de biodiversidade. Contudo, pouco se sabe sobre a resili?ncia, diversidade funcional e o processo ecol?gico que estrutura as comunidades de aves em ambientes urbanos. O presente estudo teve como objetivo investigar a riqueza de esp?cies, a diversidade funcional, a resili?ncia e o processo ecol?gico que determina a montagem das comunidades e definem os padr?es de diversidade de seis comunidades de aves em ambiente urbano. Este estudo foi desenvolvido em seis ?reas verdes com tamanhos diferentes e inseridas em matriz urbana, no munic?pio de Aracaju, Sergipe, no nordeste do Brasil. A densidade arb?rea das ?reas de estudo foram mensuradas atrav?s da contagem de indiv?duos com di?metro maior que 50 mm para investigar sua rela??o com a diversidade de aves. A riqueza, a composi??o e a frequ?ncia de ocorr?ncia das esp?cies foram investigadas, entre setembro de 2011 e julho de 2012, atrav?s do m?todo Listas de Mackinnon, adaptado para 10 esp?cies. O esfor?o amostral resultou em um total de 720 listas - 120 listas de cada ?rea. Foram observadas, no total, 82 esp?cies de aves, distribu?das em 36 fam?lias. A riqueza de esp?cies de aves aumentou em fun??o do aumento do tamanho das ?reas arborizadas. O aumento da densidade arb?rea tamb?m esteve associado ao aumento da riqueza de esp?cies de aves. Entretanto, a riqueza funcional (FRic) diminuiu em fun??o do aumento da riqueza de esp?cies. Este estudo demonstra que as comunidades de aves mais ricas possuem esp?cies com fun??es semelhantes, ou seja, s?o funcionalmente redundantes e mais resilientes a dist?rbios ambientais. Tamb?m ? poss?vel que a homogeneiza??o das comunidades de aves em ambientes urbanos ocorra atrav?s do processo de filtragem de h?bitat, que deve estruturar essas comunidades em escala local. Os filtros ambientais devem favorecer a ocorr?ncia de esp?cies com determinadas caracter?sticas funcionais e podem limitar a ocorr?ncia de esp?cies com caracter?sticas distintas.