scholarly journals The forest avifauna of Arabuko Sokoke Forest and adjacent modified habitats

2021 ◽  
Author(s):  
David Chiawo ◽  
Wellington N. Kombe ◽  
Adrian J.F.K. Craig
Keyword(s):  
Land Use ◽  
Habitat Use ◽  
Bird Species ◽  
Bird Community ◽  
Primary Forest ◽  
Future Research ◽  
Coastal Forest ◽  
Plantation Forest ◽  
Bird Populations ◽  
Vegetation Heterogeneity

Arabuko Sokoke Forest (ASF) is the largest area of coastal forest remaining in East Africa and a major Important Bird Area in mainland Kenya. The study analysed data from point count surveys over 15 months in three land use types; primary forest (PF), plantation forest (PL), and farmlands (FM), and compared these to the first comprehensive bird checklist for the forest, as well as recent surveys from other studies.  Avifaunal diversity and abundance were compared using multivariate analysis to determine bird responses to different land use characteristics. The primary forest held a distinctive bird community, while the bird communities of farmlands and plantation forest were more similar to each other. Land use had a significant effect on overall avian diversity and abundance. The current forest avifauna was divided into forest specialists (16 species), forest generalists (26 species) and forest visitors (30 species).   Seven species of forest specialist and generalists recorded prior to 1980 may no longer occur in the forest.  Of 38 specialists and generalists recorded in our point counts, 19 were also recorded on farmland and 28 in plantations.  One forest specialist, the Green Barbet, was most encountered outside the forest.  Future research should focus on habitat use by these bird species, and the extent of movement by forest birds between the remaining patches of coastal forest. Patterns of habitat use by birds in the area suggest that vegetation heterogeneity and habitat complexity are especially significant in sustaining diverse and abundant bird populations. The management of plantations and farmland will be critical for the conservation of forest generalists and forest visitors.

scholarly journals Influence of Land-Use Type on Forest Bird Community Composition in Mount Kenya Forest

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Samuel N. Mahiga ◽  
Paul Webala ◽  
Mugo J. Mware ◽  
Paul K. Ndang’ang’a
Keyword(s):  
Land Use ◽  
Species Richness ◽  
Bird Community ◽  
Natural Forest ◽  
Forest Biodiversity ◽  
Natural Forests ◽  
Plantation Forest ◽  
Point Counts ◽  
Plantation Forests ◽  
Relative Species Richness

Few studies have explored how human land uses influence and support persistence of forest biodiversity in central Kenya. In the case of the Mount Kenya ecosystem, farmlands and plantation forests are significant land-use types. Using point counts, we assessed bird communities in natural forests, plantation forests, and farmlands in the Nanyuki Forest Block, Western Mount Kenya. Bird point counts were undertaken during two sampling periods (wet and dry season). Compared to farmlands and plantation forest, natural forest had the highest overall avian species richness and relative species richness of all except one forest-dependent foraging guild (granivores) and nonforest species, which occurred frequently only on farmlands. Plantation forest had the lowest relative richness of all avian habitat and foraging guilds. Conversely, specialist forest-dependent species mainly occurred in the structurally complex remnant natural forest. Our study underscores the importance of remnant natural forests for the persistence and conservation of forest biodiversity and risks posed by replacing them with plantation forests and farmlands.

scholarly journals Shifting cultivation along the Trans-African Highway and its impact on the understorey bird community in the Ituri Forest, Zaire

1997 ◽  
Vol 7 (4) ◽  
pp. 317-329 ◽  
Author(s):  
Andrew J. Plumptre
Keyword(s):  
Species Composition ◽  
Forest Structure ◽  
Shifting Cultivation ◽  
Secondary Forest ◽  
Bird Species ◽  
Bird Community ◽  
Selective Logging ◽  
Primary Forest ◽  
Forest Sites ◽  
Ituri Forest

summarySince the 1940s, horticulturalists (the Lese) have been settled along the sides of the roads that traverse a large part of the forest in eastern Zaire. These people have maintained their lifestyle of shifting cultivation and trade with the Mbuti pygmies. This has resulted in corridors of heavily disturbed and regenerating forest. The results of a study of the understorey bird community at three sites in the Okapi Reserve in the Ituri forest in Zaire are reported here. Two primary forest sites (one monodominant Gilbertiodendron forest) in the Reserve were compared with an area of forest disturbed by shifting cultivation. The two primary forest sites were more similar in species composition than they were to secondary forest created by shifting cultivation. Shifting cultivation had a more severe impact on the bird community than selective logging does in forests in Uganda and Malaysia. There was a shift following disturbance from a bird community dominated by insectivores to one with more frugivore-insectivores and nectarivores. Ground thrushes Zoothera spp. and flycatchers were abundant in the monodominant Gilbertiodendron forest and appear to suffer from the change in forest structure following disturbance. The Okapi Reserve currently conserves some important bird species and at least 333 birds have been reported to occur there.

scholarly journals Die Entwicklung der Brutvögel in der Waldbrandfläche bei Leuk

2018 ◽  
Vol 169 (5) ◽  
pp. 299-307
Author(s):  
Livio Rey ◽  
Alain Jacot
Keyword(s):  
Large Scale ◽  
Bird Species ◽  
Bird Community ◽  
Future Research ◽  
Conservation Action ◽  
Breeding Bird ◽  
Fire Event ◽  
Positive Effects ◽  
Priority Species ◽  
Species Specific

Temporal changes of the breeding bird community in the burnt forest of Leuk Wildfires and windstorms are dynamic processes that can heavily impact habitats and alter their species compositions. Especially species of open and semi-open habitats can benefit from such disturbances, among them several bird species. In this study, we investigated the species-specific changes of the breeding bird community in the burnt forest of Leuk between 2006 and 2016, starting three years after the wildfire of 2003. Several species increased or decreased significantly in abundance after the fire event. A few species showed a complex reaction, where territory numbers increased after the fire, reaching a maximum after a few years and subsequently decreased. Interestingly, many of these bird species (e.g., Eurasian Wryneck, Common Redstart) are threatened and are priority species for conservation action. They may have benefitted from the first, open successional stages with a high proportion of bare ground, but are expected to decrease in abundance with the ongoing densification of the vegetation layers. Our study demonstrates that a large-scale forest fire can promote threatened bird species of open and semi-open habitats also in temperate regions. To what extent forestry measures, grazing or controlled fires can imitate the positive effects of wildfires is an open question and should be part of future research in the combined fields of forestry and conservation biology.

scholarly journals Disentangling the Roles of Topography, Patch, and Land Use on Conservation Trait Status of Specialist Birds in Marginal Forest Land Use Types

Forests ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 103
Author(s):  
Petr Zasadil ◽  
Dušan Romportl ◽  
Jakub Horák
Keyword(s):  
Land Use ◽  
Habitat Type ◽  
Bird Species ◽  
Bird Community ◽  
Bird Conservation ◽  
Main Question ◽  
Environmental Predictors ◽  
Patch Configuration ◽  
Marginal Forest ◽  
Fruit Orchards

One of the main questions in ecology and conservation is how organisms are governed and affected by their traits within the context of abiotic gradients. The main question of our study addresses how patch, topography, and land use influence conservation trait status (rarity and red-list index) of birds generally, and of farmland and woodland specialists specifically, in marginal forest landscape types. We sampled birds from 68 traditional fruit orchards existing as remnants of agroforestry within the Pardubice Region of the Czech Republic during two consecutive years. We recorded 57 bird species, of which 31 species were forest dwellers and 16 farmland dwellers. Topographical predictors played the most significant role in influencing traits of the bird community as a whole. Farmland bird traits indicated the most balanced values, as they were significantly influenced by all studied predictor sets. Their responses nevertheless differed among the studied traits and also showed a more complex pattern because the values of interaction between some predictor categories were relatively high. Traits of woodland birds were most influenced by the patch configuration. We found that a structurally diversified marginal habitat type of traditional fruit orchards is able to promote a number of specialist species and also reveals important relationships between bird conservation traits and different predictor sets. Researchers should pay more attention to the conservation traits of birds and their interactions with environmental predictors. Furthermore, conservationists should be more attentive to the biodiversity value and sustainable management of traditional fruit orchards.

Variations in pest bird density in Argentinean agroecosystems in relation to land use and/or cover, vegetation productivity and climate

2018 ◽  
Vol 45 (8) ◽  
pp. 668 ◽  
Author(s):  
Noelia C. Calamari ◽  
Sonia B. Canavelli ◽  
Alexis Cerezo ◽  
Sebastián Dardanelli ◽  
Jaime N. Bernardos ◽  
...  
Keyword(s):  
Land Use ◽  
Population Distribution ◽  
Bird Species ◽  
Crop Damage ◽  
Vegetation Productivity ◽  
Monk Parakeet ◽  
Bird Populations ◽  
Myiopsitta Monachus ◽  
Bird Density

Context Changes in environmental conditions may influence bird populations, including pest bird species, and their distribution. In Argentina, particularly in the Pampas region, agricultural expansion has resulted in important changes in agroecosystems, with impacts on bird species. Aims This study analysed the relationship between pest bird densities and the environmental variables associated with land use and/or cover, vegetation productivity and climate. The study focused on the most important pest bird species to grain crops in Argentina and Uruguay: the eared dove (Zenaida auriculata) and the monk parakeet (Myiopsitta monachus). Methods An area in Central Argentina was divided into three agro-productive regions, one predominantly agricultural and two with mixed production activities: agricultural rangeland and agricultural forested rangeland. Bird populations were sampled on a yearly basis between 2003 and 2011 in point-transects located along secondary roads (47 routes in total). Linear mixed models and a multi-model inference approach were used to compare the effects of individual predictive variables on bird densities. Key results Mean estimated density for the eared dove was 0.39 individuals per ha (±0.02), almost three times the density of the monk parakeet (0.10 individuals per ha±0.02). The spatial distribution of changes in density of the eared dove and monk parakeet showed irregular patterns across the study area. Density of eared dove was directly related to cover of native and exotic woodlots and inversely related to cover of fallow and weedy fields, and to temperature and rainfall. Monk parakeet density, in turn, was directly related to cover of woodlots. Conclusions The density of eared doves and monk parakeets changed mostly in relation to land use and/or cover and, to a lesser extent, to climatic conditions. Information of pest bird populations in a long-term period allowed us to understand spatial patterns in bird population distribution and to identify the main environmental factors explaining them. Implications The consideration of land use and/or cover, vegetation productivity and climate variables at regional scale, measured during a long-term period, would be critical for anticipating population increases and, possibly, increases in crop damage.

scholarly journals Haemosporidian Blood Parasites in nestling birds of prey in Mongolia

2021 ◽  
Author(s):  
Hamidreza Attaran ◽  
Jing Luo ◽  
Wang Bo ◽  
Reza Nabavi ◽  
Hong-xuan He
Keyword(s):  
Bird Species ◽  
Bird Community ◽  
Blood Parasites ◽  
Birds Of Prey ◽  
Cyt B ◽  
Bird Populations ◽  
Intracellular Parasites ◽  
Avian Haemosporidians ◽  
Cyt B Gene ◽  
Local Habitat

Haemosporidians are vector-transmitted intracellular parasites that happen in numerous bird species worldwide and may possibly have important effects for wild bird populations. Studies of haemosporidians most dedicated on Europe and North America, and only newly some study in the Neotropics has been done, where the occurrence and influences of the disease have been less considered and are not understood well. In this study we designed a study in the nestling birds of prey in Mongolia. We sampled blood from 72 raptors at 2 different species and evaluated avian haemosporidian infection by two nested PCR protocol and one Real time PCR protocol. Sequencing a portion of the cytochrome b (cyt b) gene of the parasite. From the sampled birds, 10 % were infected by Plasmodium. Inclusive, our findings advocate a high haemosporidian species richness in the bird community of Mongolia. In view of the frequency of local habitat loss that in this area is living, recognize how avian haemosporidians affect bird populations it is very important; in addition, more exhaustive sampling is required to fully understand the range of avian haemosporidian infection in this area.

Effects of acid rain on bird populations

1998 ◽  
Vol 6 (1) ◽  
pp. 41-54 ◽  
Author(s):  
Jaap Graveland
Keyword(s):  
Reproductive Success ◽  
Acid Rain ◽  
Toxic Metals ◽  
Large Scale ◽  
Bird Community ◽  
Future Research ◽  
Avian Reproduction ◽  
Forest Dieback ◽  
Bird Populations ◽  
Population Sizes

In this paper the effects of anthropogenic acidification of soils and waters on bird populations are reviewed. Acidification causes (i) declines in the reproductive success and the density of piscivorous birds through declines in the fish populations, (ii) shifts in the forest bird community from forest birds to birds of open woodland through large-scale forest dieback, and (iii) leads to a lower reproductive success of birds in calcium-poor areas through a decline in the availability of calcium-rich material (needed for eggshell formation and skeletal growth). Acidification may also affect the availability of food and nest sites for insectivorous and hole-nesting birds, but there are no consistent effects on the population sizes of these birds. Effects of declines in populations of invertebrates in aquatic habitats may be mitigated by reduced competition from fish, and acidification in forests in less-advanced stages of dieback can both lead to an increase and a decrease in insect and seed abundance in forests, the outcome depending on species, extent of leaf and needle loss, and other factors. There is some evidence that acidification may strongly affect avian reproduction through an increased exposure to toxic metals such as aluminium. Anthropogenic acidification on a worldwide scale is expected to continue during the next decades. Future research on the effects of acidification on bird populations should focus on remedial action and effects on population sizes in moderately acidified areas, and should more often apply an experimental approach than in the past.Key words: acid rain, birds, reproduction, calcium, toxic metals, forest dieback.

scholarly journals Horizontal and vertical species turnover in tropical birds in habitats with differing land use

2017 ◽  
Vol 13 (5) ◽  
pp. 20170186 ◽  
Author(s):  
Rachakonda Sreekar ◽  
Richard T. Corlett ◽  
Salindra Dayananda ◽  
Uromi Manage Goodale ◽  
Adam Kilpatrick ◽  
...  
Keyword(s):  
Land Use ◽  
Species Turnover ◽  
Bird Species ◽  
Forest Edge ◽  
Intensive Agriculture ◽  
Primary Forest ◽  
Turnover Rates ◽  
Forest Reserve ◽  
Land Use Types ◽  
Elevational Range

Large tracts of tropical rainforests are being converted into intensive agricultural lands. Such anthropogenic disturbances are known to reduce species turnover across horizontal distances. But it is not known if they can also reduce species turnover across vertical distances (elevation), which have steeper climatic differences. We measured turnover in birds across horizontal and vertical sampling transects in three land-use types of Sri Lanka: protected forest, reserve buffer and intensive-agriculture, from 90 to 2100 m a.s.l. Bird turnover rates across horizontal distances were similar across all habitats, and much less than vertical turnover rates. Vertical turnover rates were not similar across habitats. Forest had higher turnover rates than the other two habitats for all bird species. Buffer and intensive-agriculture had similar turnover rates, even though buffer habitats were situated at the forest edge. Therefore, our results demonstrate the crucial importance of conserving primary forest across the full elevational range available.

Diversity of bird feeding guilds in relation to habitat heterogeneity and land-use cover in a human-modified landscape in southern Mexico

2012 ◽  
Vol 28 (4) ◽  
pp. 369-376 ◽  
Author(s):  
Esteban Pineda-Diez de Bonilla ◽  
Jorge L. León-Cortés ◽  
José Luis Rangel-Salazar
Keyword(s):  
Land Use ◽  
Habitat Heterogeneity ◽  
Bird Species ◽  
Bird Community ◽  
Bird Diversity ◽  
Feeding Guilds ◽  
Fragmented Landscape ◽  
Secondary Forests ◽  
Southern Mexico ◽  
Point Counts

Abstract:Habitat heterogeneity is an important ecological determinant of species richness. We evaluated the diversity within bird feeding guilds as related to habitat heterogeneity and land-use cover in a human-modified tropical landscape. To quantify this process, fine-scale bird census and habitat heterogeneity data were collected for a bird community in a 22.5-km2fragmented landscape in southern Mexico. Land-use cover data derived from field surveys were used to calculate habitat heterogeneity index values and the extent of each land-use cover type in 239 grid cells of 300 × 300 m. Bird diversity values were obtained based on 1195 point-counts in these cells. Product-moment correlations and linear regression analyses were used to evaluate the relationship between bird-guild diversity values and habitat heterogeneity. A total of 109 resident bird species grouped in six feeding guilds were recorded: insectivores (42%), frugivores (21%), granivores (17%), nectarivores (9%), omnivores (8%) and carnivores (3%). Diversity values for the entire bird community were significantly positively related to habitat heterogeneity, but feeding guilds showed contrasting responses to habitat heterogeneity and the amount of land-use cover: insectivores and frugivores were more diverse and abundant in secondary forests than in any other land-cover. Our findings illustrate the importance of small landscape fragments as potential key refuges for the most diverse and specialized feeding guilds, such as granivores and insectivores.

scholarly journals Influence of the configuration and heterogeneity of the agroforestry and silvopastoral mosaics on the bird community, Andean Amazon of Colombia

2019 ◽  
Vol 67 (1) ◽  
Author(s):  
Alexander Velásquez Valencia ◽  
Maria Argenis Bonilla Gómez
Keyword(s):  
Land Use ◽  
Production System ◽  
Vegetation Cover ◽  
Production Systems ◽  
Bird Species ◽  
Bird Community ◽  
Landscape Conservation ◽  
Species Accumulation Curves ◽  
Grazing Land ◽  
General Terms

General changes in land use have established patterns of modification of native vegetation into agricultural and grazing land. These production systems, as well as social and economic influences, have created diverse landscapes - mosaics composed of varied elements of vegetation cover (forests, crops, pastures, barren fields) that are distributed across spaces in different ways. In this investigation, we determine the distribution patterns of the richness, abundance and diversity of the bird community within the configuration and composition of agroforestry and silvopastoral landscapes. We observed 262 bird species, 6 720 individuals, 23 orders and 54 families within 39 production system mosaics. None of the species accumulation curves in the production systems reached their asymptote, and the calculated estimators predicted a greater number of species than those observed during the survey. In general terms, richness, diversity and equitability indices were highest in the mosaics of agroforestry systems, while abundance and dominance indices were highest in the mosaics associated with silvopastoral and traditional livestock systems. Variables that describe vegetation cover in mosaics have different and independent effects on the diversity of bird assemblages and on the association of land use groups within the mosaics. The positive extreme of the first component contributes to the variance in the model of richness and diversity indices - both the structural components of landscapes and biological components of the assemblages. The area and disposition of different types of elements in the mosaics of the production system landscapes reflect the systematic management of covers, which affects the implications of landscape conservation and restoration practices. Different landscape elements serve as points of contact in the dispersion and distribution of species within these landscapes. The priority of conservation efforts and the first step for the restoration and connectivity of landscapes in the Andean Amazon of Colombia should be the management and protection of covers like old stubble or BFG and BRP. Another approach is the design of landscapes for entire communities of species with respect to certain quantities of habitats in the landscape and the isolation of patches.

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