Intensive agricultural developments and increasing human population has caused severe lowland-forest loss and fragmentation in the western coastal plain in Taiwan over the past centuries. The goal of this study is to explore the multiscale impacts of forest fragmentation on species richness and community composition of lowland-forest birds in Taiwan. At a regional scale, Island Biogeography Theory was applied to examine area and isolation effects on species richness of lowland-forest birds using bird data derived from Breeding Bird Survey Taiwan in 2009 and 2010. I also investigate the differential responses of two functional groups (forest specialists and generalists) to area and isolation effects Furthermore, I examine the relative influences of environmental variables at regional, landscape and local scales on avian community indices and composition in northern Taiwan with a hierarchical multiscale approach. Finally, species vulnerable to forest fragmentation and the ecological traits associated with specie vulnerability to forest fragmentation were identified. Only forest specialist species responded to the regional-scale area and isolation effects. The species richness of forest specialists increased with the size of forest islands, and the community similarity of forest specialist species declined with increasing the distance from the sources of immigrants. Structurally isolated forests may not function as real habitat patches from the view of forest generalists because of their flexibility in utilizing the non-forest matrix. After accounting for the influences of environmental variables at other spatial scales, the regional-scale isolation effect still played a key role in determining avian community composition based on the  presence/absence data set. But local-scale forest condition also explained a considerable amount of variability in the presence/absence data set. The regional-scale isolation effect, however, didn't show significant influences on community composition based on the abundance data set. In contrast, the landscape-scale variables explained the largest amount of variability in the abundance data set at the entire community level. There were six bird species (Parus varius, Dicrurus aeneus, Treron sieboldii, Pericrocotu solaris, Erporniszan tholeuca and Alcippe brunnea) whose occurrence and abundance were both vulnerable to forest fragmentation. Habitat specialization was the ecological traits most strongly associated with their vulnerability / Ph. D.

No description available.

No description available.

Examination of bird assemblages along an environmental gradient which encompasses both climate and habitat change is needed if we are to better understand the potential effects of these changes for avians and the ecological process that depend upon them. Climate change is predicted to have a significant impact on deserts and desert margins, resulting in distributional shifts of entire ecosystems and new community associations. This study explores the probable responses of avian communities to increasing desertification. In general, species richness and numbers of birds in arid zones are low compared to more mesic areas. Different combinations of habitat types and the variety of patches in a landscape influence the diversity and community structures of avians in that landscape. The role of vegetation structure in avian habitat selection in semi-arid areas is dictated by horizontal habitat density as well as vertical structure. Although bird distribution is determined by habitat boundaries, most birds are flexible and can disperse across small habitat barriers. The hypothesis tested, was that bird species assemblages along an aridity gradient are affected primarily by rainfall and secondarily by habitat type. Assessing the impacts of rainfall and habitat on bird variables, such as species richness, abundance, diversity, biomass, and life history traits, were the objectives of the study. An east-west aridity gradient of 300 mm, stretching over 370 km, was chosen in central Namibia for the study area. The climate is harsh with localised rain and considerable daily fluctuations in temperature. Grasses, and trees and shrubs up to 7 m in height are the co-dominant life-forms. Surveys were conducted over three years; one winter and one summer survey in each year. Rainfall, seasons and vegetation height were recorded as environmental variables. Three structurally different habitat types were selected for stratified sampling: open areas, rivers and thickets. Open areas were dominated by grass; river refers to ephemeral dry river lines with mature trees; and thickets comprise woody shrubs and trees. At each site, the same three habitats were used for bird sampling, resulting in 15 sample units. Sampling took place on 51 discontinuous line transects of 1km in length and without a width limit. Univariate analyses included ANOVA and t-tests. Multivariate analyses consisted of cluster analysis, MRPP tests, indicator analysis, Shannon diversity index and NMS ordinations. NMS bi-plots were used to define avian community structures responding to aridity, habitat, migration and life history traits. The results showed that bird species richness, abundance, and diversity remained relatively constant across the aridity gradient, until they declined significantly once a certain aridity threshold was crossed at the most arid site. There were significantly more bird species and individual birds at the wetter sites than at the drier sites. Rivers contained more birds than thickened or open habitat types, suggesting the importance of riparian habitat types for maintaining avian diversity. The three more mesic sites included higher numbers of species from the nesting and feeding guilds, regardless of habitat type, than the two more arid sites. The aridity threshold had a significant effect on bird community structures: more migrant and nomadic species, and omnivore and insectivore species persisted in very arid conditions. From the results it was predicted that climate change will cause avian species to undergo range shifts from west to east, resulting in community composition changes and a reduction in diversity. Life history traits affect the adaptive capabilities of bird species and it is predicted that nomadism, flexibility in diet, and adaptability of nesting requirements will contribute to species persistence in the drier conditions predicted under current climate change scenarios. Dry river lines will act as refugia for avian diversity, but crucial habitat types that currently contain less diversity are also important for maintaining unique avian assemblages. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

Examination of bird assemblages along an environmental gradient which encompasses both climate and habitat change is needed if we are to better understand the potential effects of these changes for avians and the ecological process that depend upon them. Climate change is predicted to have a significant impact on deserts and desert margins, resulting in distributional shifts of entire ecosystems and new community associations. This study explores the probable responses of avian communities to increasing desertification. In general, species richness and numbers of birds in arid zones are low compared to more mesic areas. Different combinations of habitat types and the variety of patches in a landscape influence the diversity and community structures of avians in that landscape. The role of vegetation structure in avian habitat selection in semi-arid areas is dictated by horizontal habitat density as well as vertical structure. Although bird distribution is determined by habitat boundaries, most birds are flexible and can disperse across small habitat barriers. The hypothesis tested, was that bird species assemblages along an aridity gradient are affected primarily by rainfall and secondarily by habitat type. Assessing the impacts of rainfall and habitat on bird variables, such as species richness, abundance, diversity, biomass, and life history traits, were the objectives of the study. An east-west aridity gradient of 300 mm, stretching over 370 km, was chosen in central Namibia for the study area. The climate is harsh with localised rain and considerable daily fluctuations in temperature. Grasses, and trees and shrubs up to 7 m in height are the co-dominant life-forms. Surveys were conducted over three years; one winter and one summer survey in each year. Rainfall, seasons and vegetation height were recorded as environmental variables. Three structurally different habitat types were selected for stratified sampling: open areas, rivers and thickets. Open areas were dominated by grass; river refers to ephemeral dry river lines with mature trees; and thickets comprise woody shrubs and trees. At each site, the same three habitats were used for bird sampling, resulting in 15 sample units. Sampling took place on 51 discontinuous line transects of 1km in length and without a width limit. Univariate analyses included ANOVA and t-tests. Multivariate analyses consisted of cluster analysis, MRPP tests, indicator analysis, Shannon diversity index and NMS ordinations. NMS bi-plots were used to define avian community structures responding to aridity, habitat, migration and life history traits. The results showed that bird species richness, abundance, and diversity remained relatively constant across the aridity gradient, until they declined significantly once a certain aridity threshold was crossed at the most arid site. There were significantly more bird species and individual birds at the wetter sites than at the drier sites. Rivers contained more birds than thickened or open habitat types, suggesting the importance of riparian habitat types for maintaining avian diversity. The three more mesic sites included higher numbers of species from the nesting and feeding guilds, regardless of habitat type, than the two more arid sites. The aridity threshold had a significant effect on bird community structures: more migrant and nomadic species, and omnivore and insectivore species persisted in very arid conditions. From the results it was predicted that climate change will cause avian species to undergo range shifts from west to east, resulting in community composition changes and a reduction in diversity. Life history traits affect the adaptive capabilities of bird species and it is predicted that nomadism, flexibility in diet, and adaptability of nesting requirements will contribute to species persistence in the drier conditions predicted under current climate change scenarios. Dry river lines will act as refugia for avian diversity, but crucial habitat types that currently contain less diversity are also important for maintaining unique avian assemblages. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

Apesar de vários estudos já terem examinado os efeitos de queimadas naturais, respostas das aves, como variação do padrão da comunidade, guilda trófica e das espécies, ao manejo de fogo ainda não foram investigadas em reservas do Cerrado, Este trabalho teve como objetivo comparar a avifauna em trechos de campo sujo manejados (aceiros) e não manejados por fogo no Parque Nacional das Emas, Brasil Central. Este é o primeiro trabalho a avaliar os efeitos do manejo do fogo prescrito sobre comunidades de aves no Cerrado. Foram selecionados 12 locais de estudo. Em cada local, havia um transecto no aceiro e outro em campo sujo não manejado. Uma amostra consistiu em percorrer um transecto de 800m a pé, anotando as aves detectadas visual ou auditivamente a 15m do observador. Frequência de ocorrência e abundância das espécies e das guildas tróficas, riqueza total, abundância total da comunidade de aves e composição de espécies encontradas nos dois ambientes foram comparadas. No total, foram 881 registros e 41 espécies de aves. A riqueza e a abundância total de aves foram significativamente menores em aceiros. Houve diferença na composição de espécies de aves entre campos não manejados por fogo e aceiros. Dentre as guildas tróficas, os onívoros foram mais frequentes em campos não manejados. Granívoros, nectarívoros e onívoros foram mais abundantes em vegetação não manejada. Das 21 espécies analisadas separadamente, a coruja Athene cunicularia foi a única indicadora de aceiros e também mais frequente e abundante em aceiros. Por outro lado, foram identificadas quatro espécies indicadoras de campos sujos não manejados (Melanopareia torquata, Xolmis cinerea, Neothraupis fasciata e Coryphaspiza melanotis). Tais espécies podem ser usadas como indicadores ecológicos do regime e histórico do fogo e podem fornecer informações se os objetivos das ações de manejo do fogo estão sendo atingidos. Sete espécies foram mais frequentes e oito espécies foram mais abundantes em campos não manejados. Três dessas espécies são endêmicas do Cerrado (M. torquata, N. fasciata e Cypsnagra hirundinacea) e quatro estão sob algum grau de ameaça e são altamente sensíveis a distúrbios (Polystictus pectoralis, Alectrurus tricolor, C. melanotis e C. hirundinacea). Assim, cuidado e atenção devem ser redobrados para essas espécies, pois possuem alto valor para conservação e menor frequência ou abundância em aceiros. A menor riqueza e abundância de aves encontrada em aceiros devem estar relacionadas ao menor uso desse habitat, indicando menor disponibilidade de recursos como alimento, reprodução e abrigo, dado que o fogo altera a estrutura e composição da vegetação. Isso demonstra uma diminuição da qualidade do ambiental geral dos aceiros, provocada pela sua atual forma de manejo. Propomos que a queima dos aceiros seja feita em intervalos de 3 anos, em vez de 1 2 anos como tem sido realizada. Dessa forma, seria mantida a função dos aceiros como controle e barreira efetiva de incêndios e também para conservação da biodiversidade. / Several studies have investigated the effects of natural fires on Cerrado birds. However, avian responses to fire management have not been examined. We compared birds found in firebreaks (fire managed areas) and in fire unmanaged grasslands, in Parque Nacional das Emas, Central Brazil. This is the first study to evaluate the effects of prescribed fire on the Cerrado avifauna. We selected 12 study sites. We established one transect in the firebreak and another one in an unmanaged grassland area in each study site. Each bird count sample consisted of walking through an 800m transect recording birds seen or heard 15m from the observer. Species richness, total bird abundance, species composition, feeding guilds abundance and frequencies of occurrence and species abundance found in firebreaks and unmanaged grasslands were compared. In total, 881 individuals and 41 species were recorded. Species richness and total abundance were significantly lower in firebreaks. Species composition was different between firebreaks and unmanaged grasslands. Omnivores were more frequent and more abundant in unmanaged grasslands. Granivores and nectarivores were more abundant in unmanaged grasslands. Twenty-one bird species were analyzed separately, one of which (Athene cunicularia) was indicator of firebreaks and also more frequent and abundant in firebreaks. On the other hand, we identified four indicator species of unmanaged grasslands (Melanopareia torquata, Xolmis cinerea, Neothraupis fasciata and Coryphaspiza melanotis). These species might be used as ecological indicators of fire regime and history, and also give information if fire management goals are being achieved. Seven species were more frequent and eight species were more abundant in unmanaged grasslands. Three of them are endemic of Cerrado (M. torquata, N. fasciata and Cypsnagra hirundinacea) and four of them are highly sensitive to human disturbances and threatened with extinction in some degree (Polystictus pectoralis, Alectrurus tricolor, C. melanotis e C. hirundinacea). Caution must be redoubled to these species, as they are of high conservation priority and less frequent and abundant in firebreaks. The lesser avifauna complexity in firebreaks than in unmanaged areas might be connected to the low use of this habitat, thus indicating lower resource availability, such as food, sites for reproduction and refuge. This is because fire changes vegetation structure and composition. We propose that firebreaks should be burnt every 3 years, instead of 1-2 years. In this way, fire management would keep its function as effective fire barriers and would also keep biodiversity conservation.

ABSTRACT AVIAN COMMUNITY PATTERNS IN THE LESSER CAUCASUS (NORTHEASTERN TURKEY) ATKIN GEN&Ccedil / OgLU, G&uuml / lden M. Sc., Department of Biological Sciences Supervisor: Assoc. Prof. Dr. C. Can Bilgin December 2007, 78 pages Species composition, diversity and species-habitat relations are widely used to describe communities. This study aimed to document diversity, composition and habitat relations of avian communities of the Turkish Lesser Caucasus by using point counts and multivariate analyses. 2845 individuals of 101 bird species were observed at 215 stations located in the study area. Point counts were revealed to be a useful method for terrestrial birds, especially passerines. Species richness and diversity changed significantly within parts of the study area and one particular sub-region was found to be considerably more diverse than the other three. Division of the Lesser Caucasus region into sub-ecoregions may not be justified using bird assemblages since habitat parameters, especially the presence of woody vegetation, seemed to be a better predictor of species composition than geographical proximity. Documented bird and habitat associations provide valuable information on the factors which affect bird occurrence or abundance. Baseline data provided by this study will help detect and understand changes in bird populations in the future. Keywords: avian community, species composition, species diversity, point count method, bird-habitat relationship

Apesar de vários estudos já terem examinado os efeitos de queimadas naturais, respostas das aves, como variação do padrão da comunidade, guilda trófica e das espécies, ao manejo de fogo ainda não foram investigadas em reservas do Cerrado, Este trabalho teve como objetivo comparar a avifauna em trechos de campo sujo manejados (aceiros) e não manejados por fogo no Parque Nacional das Emas, Brasil Central. Este é o primeiro trabalho a avaliar os efeitos do manejo do fogo prescrito sobre comunidades de aves no Cerrado. Foram selecionados 12 locais de estudo. Em cada local, havia um transecto no aceiro e outro em campo sujo não manejado. Uma amostra consistiu em percorrer um transecto de 800m a pé, anotando as aves detectadas visual ou auditivamente a 15m do observador. Frequência de ocorrência e abundância das espécies e das guildas tróficas, riqueza total, abundância total da comunidade de aves e composição de espécies encontradas nos dois ambientes foram comparadas. No total, foram 881 registros e 41 espécies de aves. A riqueza e a abundância total de aves foram significativamente menores em aceiros. Houve diferença na composição de espécies de aves entre campos não manejados por fogo e aceiros. Dentre as guildas tróficas, os onívoros foram mais frequentes em campos não manejados. Granívoros, nectarívoros e onívoros foram mais abundantes em vegetação não manejada. Das 21 espécies analisadas separadamente, a coruja Athene cunicularia foi a única indicadora de aceiros e também mais frequente e abundante em aceiros. Por outro lado, foram identificadas quatro espécies indicadoras de campos sujos não manejados (Melanopareia torquata, Xolmis cinerea, Neothraupis fasciata e Coryphaspiza melanotis). Tais espécies podem ser usadas como indicadores ecológicos do regime e histórico do fogo e podem fornecer informações se os objetivos das ações de manejo do fogo estão sendo atingidos. Sete espécies foram mais frequentes e oito espécies foram mais abundantes em campos não manejados. Três dessas espécies são endêmicas do Cerrado (M. torquata, N. fasciata e Cypsnagra hirundinacea) e quatro estão sob algum grau de ameaça e são altamente sensíveis a distúrbios (Polystictus pectoralis, Alectrurus tricolor, C. melanotis e C. hirundinacea). Assim, cuidado e atenção devem ser redobrados para essas espécies, pois possuem alto valor para conservação e menor frequência ou abundância em aceiros. A menor riqueza e abundância de aves encontrada em aceiros devem estar relacionadas ao menor uso desse habitat, indicando menor disponibilidade de recursos como alimento, reprodução e abrigo, dado que o fogo altera a estrutura e composição da vegetação. Isso demonstra uma diminuição da qualidade do ambiental geral dos aceiros, provocada pela sua atual forma de manejo. Propomos que a queima dos aceiros seja feita em intervalos de 3 anos, em vez de 1 2 anos como tem sido realizada. Dessa forma, seria mantida a função dos aceiros como controle e barreira efetiva de incêndios e também para conservação da biodiversidade. / Several studies have investigated the effects of natural fires on Cerrado birds. However, avian responses to fire management have not been examined. We compared birds found in firebreaks (fire managed areas) and in fire unmanaged grasslands, in Parque Nacional das Emas, Central Brazil. This is the first study to evaluate the effects of prescribed fire on the Cerrado avifauna. We selected 12 study sites. We established one transect in the firebreak and another one in an unmanaged grassland area in each study site. Each bird count sample consisted of walking through an 800m transect recording birds seen or heard 15m from the observer. Species richness, total bird abundance, species composition, feeding guilds abundance and frequencies of occurrence and species abundance found in firebreaks and unmanaged grasslands were compared. In total, 881 individuals and 41 species were recorded. Species richness and total abundance were significantly lower in firebreaks. Species composition was different between firebreaks and unmanaged grasslands. Omnivores were more frequent and more abundant in unmanaged grasslands. Granivores and nectarivores were more abundant in unmanaged grasslands. Twenty-one bird species were analyzed separately, one of which (Athene cunicularia) was indicator of firebreaks and also more frequent and abundant in firebreaks. On the other hand, we identified four indicator species of unmanaged grasslands (Melanopareia torquata, Xolmis cinerea, Neothraupis fasciata and Coryphaspiza melanotis). These species might be used as ecological indicators of fire regime and history, and also give information if fire management goals are being achieved. Seven species were more frequent and eight species were more abundant in unmanaged grasslands. Three of them are endemic of Cerrado (M. torquata, N. fasciata and Cypsnagra hirundinacea) and four of them are highly sensitive to human disturbances and threatened with extinction in some degree (Polystictus pectoralis, Alectrurus tricolor, C. melanotis e C. hirundinacea). Caution must be redoubled to these species, as they are of high conservation priority and less frequent and abundant in firebreaks. The lesser avifauna complexity in firebreaks than in unmanaged areas might be connected to the low use of this habitat, thus indicating lower resource availability, such as food, sites for reproduction and refuge. This is because fire changes vegetation structure and composition. We propose that firebreaks should be burnt every 3 years, instead of 1-2 years. In this way, fire management would keep its function as effective fire barriers and would also keep biodiversity conservation.

I assessed fish community data collected by the Oklahoma Conservation Commission from 82 minimally impaired wadeable reference streams in eastern Oklahoma to determine whether existing aquatic ecoregions provide the best framework for spatial classification for the development of biological assessment methods and biocriteria. I used indirect ordination and classification to identify groups of sites that support similar fish communities. Although correspondence was observed between fish assemblages and three montane ecoregions, the classification system must be refined and expanded to include major drainage basins and physical habitat attributes for some areas to adequately partition variance in key measures of biological integrity. Results from canonical correspondence analysis indicated that substrate size and habitat type were the primary physical habitat variables that influenced the fish species composition and community structure.

No description available.