Forest Bird Diversity Research Articles

Diversity and population densities of coraciiform birds in Zambezi riparian forest

A territory mapping method was used in 2015 to assess the population density of coraciiform species breeding in a riparian forest on the Zambezi River near Katima Mulilo, NE Namibia. The forest, c. 280 ha in surface area, was partly transformed by human settlement and arable grounds. A total of 13 species and 42 breeding pairs were recorded. Population densities were (pairs/100 ha) as follows: grey–headed kingfisher 4.3; giant, pied and woodland kingfisher, each one with 1.1; malachite kingfisher 0.7; striped kingfisher 0.4; white–fronted bee–eater 1.4; little bee–eater 1.1; lilac–breasted roller 0.7; broad–billed roller 1.1; African hoopoe 0.7; red–billed wood–hoopoe 1.1; and scimitar–billed wood–hoopoe 0.4. Data published through GBIF (Doi: 10.15470/s9rlud).

Retention Forestry Supports Bird Diversity in Managed, Temperate Hardwood Floodplain Forests

The retention forestry approach is considered as one of the potentially effective tools for sustainable forest management for conservation of biodiversity in managed temperate and boreal forests. Retention of old-growth forest structures (e.g., very large old living trees) in forest stands during clear-cutting provides maintenance of key habitats for many old-growth forest interior-species. Most of ecological studies on green tree retention (GTR) consequences for biodiversity have been focused on birds. However, the long-term studies of GTR impacts on forest birds are very poor. In this paper, we focused on assessment of the long-term consequences of leaving legacy oak trees on the cut areas for bird diversity 18–22 years after clear-cutting in managed temperate European hardwood floodplain forests. Results based on bird counting using mapping of bird nesting territories revealed a key importance of legacy oak trees for maintaining bird diversity in the study area. These results are widely applicable for managed temperate hardwood forests with serious dominance of oak (Quercus sp.) in forest stands. Legacy oak trees in this habitat type are keystone structures for bird diversity. Retention approach focused on these trees is potentially an important conservation tool for preserving forest bird diversity and other associated species in temperate hardwood forests managed by clear-cutting.

Salmon increase forest bird abundance and diversity.

Resource subsidies across ecosystems can have strong and unforeseen ecological impacts. Marine-derived nutrients from Pacific salmon (Onchorhycus spp.) can be transferred to streams and riparian forests through diverse food web pathways, fertilizing forests and increasing invertebrate abundance, which may in turn affect breeding birds. We quantified the influence of salmon on the abundance and composition of songbird communities across a wide range of salmon-spawning biomass on 14 streams along a remote coastal region of British Columbia, Canada. Point-count data spanning two years were combined with salmon biomass and 13 environmental covariates in riparian forests to test for correlates with bird abundance, foraging guilds, individual species, and avian diversity. We show that bird abundance and diversity increase with salmon biomass and that watershed size and forest composition are less important predictors. This work provides new evidence for the importance of salmon to terrestrial ecosystems and information that can inform ecosystem-based management.

Evaluating the long-term effectiveness of terrestrial protected areas: a 40-year look at forest bird diversity

Designation of protected areas has become one of the primary approaches to reducing biodiversity loss, with the number of new set-asides growing in the last decades largely from the addition of small protected areas to the global portfolio. Information on the effectiveness of protected areas to stave off species extinction is surprisingly scarce, with almost nothing known about the long-term fate of biodiversity in smaller protected temperate forests. Here we use an uncommonly complete biodiversity inventory of a small protected deciduous forest to evaluate its performance over a 40-year time span. We tracked bird compositional changes using a within-season repeat sampling protocol allowing us unusual accuracy in documenting species gains and losses through time. We found that nearly half the species found in the forest at the time of initial protection are now extirpated, and that yearly forest species composition is highly dynamic. Ground nesting and migratory species were more likely to be extirpated than were canopy breeders, cavity nesters, and year-round residents. Regional population declines explained differences in extirpation probability across species indicating that the study population, to some extent, mirrored larger regional dynamics. However, a substantial number of species declined in abundance within the forest while experiencing no regional declines, or even regional increases, in abundance. Our results reinforce that even with protected status, small forest fragments may not provide the conservation benefits that protection is meant to provide.

High critical forest habitat thresholds of native bird communities in Afrotropical agroforestry landscapes

Our knowledge on the relationship between tropical forest cover and biotic communities is still limited. Understanding the relationship between forest cover and bird functional guilds may serve as a valuable tool to assess how much forest is necessary to conserve significant portions of typical forest assemblages. We sampled birds (198 species, 6883 encounters) along a full gradient of deforestation across 4000 km2 of forest-dominated landscapes in Southwest Cameroon and applied multivariate adaptive regression splines to model α-, β- and γ-richness of guilds in relation to forest cover. Overall, β- and γ-richness remained constant above 42% forest cover. However, total α-richness as well as all richness partitions of Guinea-Congo biome-restricted, large-bodied arboreal foliage gleaning, tree nesting, and frugivorous species declined when forest cover was below 74%. Moreover, ant-followers and terrestrial insectivores showed their highest diversity at zero deforestation. In contrast, open-land, granivorous, opportunistic insectivorous and widespread species strongly increased below 42% forest cover. High β-diversity at intermediate deforestation conditions indicate that the sharp decline of original forest bird diversity may only be compensated by habitat and foraging generalists, which benefit from high habitat heterogeneity. Our study implies that Afrotropical forest bird diversity decreases non-linearly with forest loss. Critical habitat thresholds estimated by us at above 70% are much higher than those previously reported and highlight the need to integrate substantial proportions of natural vegetation within wildlife friendly farming schemes.

Diversity and conservation threats of water birds in and around Barandabhar corridor forest, Chitwan, Nepal

Wetlands provide major ecological services for feeding and breeding places of a large number of water birds in many parts of the globe and also play a vital role in conservation of threatened species. Wetlands in Nepal support a total of 27% of nationally threatened birds. Barandabhar forest is only one vertical (south-north) bio-corridor that links two different ecosystems, CNP and the Mahabharat hill range. Eight wetlands were selected for water birds monitoring by using area search and point count methods to explore the diversity and conservation threats of water birds in Barandabhar corridor forest. This study recorded 3664 individuals of water birds belonging to 54 species, 11 orders and 13 families in which the highest numbers of the species were belonged to order Passeriformes (17 species). The diversity of water birds in eight different wetlands showed the highest diversity in Rapti river (H= 3.403), followed by Beeshazari lakesystem (H= 3.401), Batulpokari lake area (H= 3.377) and the rest of others. The least diversityof water birds was found in Gundremandre lake (H=2.210). Similarly, the species dominance was more in Gundremandre lake (D=0.189) than Beeshazari (D=0.046) and Batulpokhari (D=0.042). The species richness in various habitats association with wetlands showed that Shorea forest association was utilized very less as compared to its availability. Fishermen (r= -0.391, t = 10.6, P<0.0001) and livestock pressure (r = -0.276, t = 6.63, P = 0.0009) caused the significant negative impact on the occurrence of water birds in many parts of the study sites. The study suggests that annual flooding in the rivers (e.g., Rapti, Budhirapti and Khageririvers), human disturbance (e.g., livestock grazing and fishing), habitat loss and degradation, declining water quality and quantity caused by eutrophication and chemical pollution are the major threats of water bird communities in Barandabhar corridor forest.

The relative effects of forest amount, forest configuration, and urban matrix quality on forest breeding birds

Urbanization modifies landscape structure in three major ways that impact avian diversity in remnant habitat: habitat amount is reduced and habitat configuration and matrix quality are altered. The relative effects of these three components of landscape structure are relatively well-studied in agricultural landscapes, but little is known about the relative effect of urban matrix quality. We addressed this gap by investigating the relative effects of forest amount, forest configuration, and matrix quality, indicated by degree of urbanization and agriculture amount, on the diversity of three guilds of forest birds using data from 13,763 point counts from Pennsylvania, USA. Forest amount had the largest independent effect on forest bird diversity, followed by matrix quality, then forest configuration. In particular, urbanization had strong negative effects on the relative abundance and species evenness of all forest birds and the relative abundance of forest generalist birds. To our knowledge, these are the first results of the effect of urban matrix quality on forest bird relative abundance and species evenness independent of forest amount and forest configuration. Our results imply that conservation practitioners in human-modified landscapes prioritize maximizing forest amount, then reducing the effects of disturbances originating in the matrix, and then preserving large, spatially-dispersed forest patches to most effectively conserve forest birds.

Characterising the richness and diversity of forest bird species using National Forest Inventory data in Germany

Data collected by forest inventories like the third National Forest Inventory (NFI-3, 2011–2012) in Germany was proposed to monitor forest biodiversity and evaluate existing forest management practices on a national scale. A data set was created from the NFI-3 data for analysis purposes which contained variables relevant to the habitat requirements of native forest bird species. Information on the distribution and abundance of 20 native forest bird species was taken from the Atlas of German Breeding Birds (2005–2009, 3003 grid cells). They form two important ecological groups: cavity-nesting and deciduous forest birds. For the first time, this data was combined with NFI-3 data and analysed using Random Forest models and partial dependence plots to determine which forest variables recorded by the NFI-3 were most closely related to forest bird species richness and diversity in temperate forests.It was shown that changes in forest bird species diversity and richness correlate with the NFI data but the different sampling methods of the NFI and bird species data also created methodological challenges which are discussed. The most important drivers of the richness and diversity of deciduous forest and cavity-nesting bird species are forest stand age and forest ownership. Deciduous forest and cavity-nesting birds show a preference for the way state, federal and municipal forests are managed over private forests. Private forests have significantly lower deadwood volumes and high proportions of coniferous trees, both of which are forest characteristics that lower the richness and diversity of bird species. Our findings show that efforts to protect forest birds should target managed forests older than 100 and 200 years and forests with total deadwood volumes >46.3 m3/ha. Protected areas also exhibited higher diversity and richness of forest birds which highlight their importance as suitable target areas for the protection of forest birds.

Cropland patchiness strongest agricultural predictor of bird diversity for multiple guilds in landscapes of Ontario, Canada

The potential for agricultural landscapes to support biodiversity may vary greatly based on agricultural land use. Current knowledge suggests that agricultural composition and intensity are dominant drivers of biodiversity in agricultural landscapes, with variable effects of agricultural configuration and landscape diversity. The aim of this study was to determine the relative effects of agricultural composition, intensity, configuration, and landscape diversity on the species diversity of six distinct bird guilds on the landscape scale in a large and complex landscape in Ontario, Canada. We found that agricultural configuration, specifically patchiness of croplands, and to a lesser degree forage lands, was the strongest predictor of bird diversity for three of the six bird guilds considered (forest, shrubland, and town). The effects of increased cropland patchiness were variable, with forest and shrubland bird diversity increasing from small to moderate patchiness, and town bird diversity declining from moderate to high patchiness. Grassland birds, a group of considerable conservation concern, increased near linearly with increased agricultural land cover in the landscape, highlighting the need to consider agricultural lands in conservation planning for this species group. Woodland bird diversity declined significantly with all increasing measures of agricultural intensity, including the proportion of high-intensity agriculture and larger patches of agricultural land. Wetland birds were unique from the other guilds, showing primarily a strong association between diversity of land cover types and guild-level bird diversity. Surprisingly, increased cover of agricultural lands, which we predicted to be a dominant driver of guild-level bird diversity declines due to habitat loss, had weak, non-significant effects relative to the other land use variable being tested, except for the positive association with grassland birds. Our findings suggest that a mix of management strategies should be employed to consider the varying effects of agricultural lands on different bird guilds, such as the inclusion of agricultural land in conservation strategies for grassland species and further managing the configuration of agricultural lands to enhance biodiversity of agricultural landscapes.

Hidden diversity of forest birds in Madagascar revealed using integrative taxonomy

Madagascar is renowned as a global biodiversity hotspot with high levels of microendemism. However, there are few molecular phylogenetic studies of Malagasy birds, particularly for forest-dwelling species, signifying a substantial gap in current measures of species diversity in the absence of genetic data. We evaluated species limits and explored patterns of diversification within the genus Newtonia (Family Vangidae), a group of forest-dwelling songbirds endemic to Madagascar. Our modern systematics approach combined genomic, morphometric, and ecological niche data to analyze the evolutionary history of the group. Our integrative analysis uncovered hidden species-level diversity within N. amphichroa, with two deeply divergent and morphologically distinct lineages isolated in different regions of humid forest. We describe the southern lineage as a new species. Conversely, N. brunneicauda, which we initially hypothesized may harbor cryptic diversity owing to its large distribution spanning a range of habitats, was found to have no distinct lineages and shared haplotypes across much of its distribution. The contrasting diversification patterns between Newtonia lineages may be the result of their elevational tolerances. Newtonia brunneicauda has a broad habitat tolerance and elevational range that appears to have facilitated population expansion and gene flow across the island, limiting opportunities for diversification. On the other hand, N. amphichroa is found predominantly in mid-elevation and montane humid forests, a restriction that appears to have promoted speciation associated with climatic fluctuations during the Pleistocene. Our findings indicate that species diversity of Malagasy forest-dwelling birds may be greater than currently recognized, suggesting an urgent need for further studies to quantify biodiversity in Madagascar’s rapidly disappearing native forests.

Contrasting impacts of land‐use change on phylogenetic and functional diversity of tropical forest birds

Abstract Biodiversity conservation strategies increasingly target maintaining evolutionary history and the resilience of ecosystem function, not just species richness (SR). This has led to the emergence of two metrics commonly proposed as tools for decision making: phylogenetic diversity (PD) and functional diversity (FD). Yet, the extent to which they are interchangeable remains poorly understood. We explore shifts in and relationships between FD and PD of bird communities across a disturbance gradient in Borneo, from old‐growth tropical forest to oil palm plantation. We show a marked decline in PD, and an increase in phylogenetic mean nearest taxon distance from forest to oil palm, in line with declining SR across the gradient. However, phylogenetic mean pairwise distance is constrained by forest logging more than by conversion to oil palm, taking account of SR. The decline in FD across the gradient is less severe than in PD, with all metrics indicating relatively high trait diversity in oil palm despite low SR, although functional redundancy is much reduced. Accounting for SR, levels of functional over‐ or under‐dispersion of bird communities are strongly coupled to habitat disturbance level rather than to any equivalent phylogenetic metric. Policy implications. We suggest that while phylogenetic diversity (PD) is an improvement on species richness as a proxy for functional diversity (FD), conservation decisions based on phylogenetic diversity alone cannot reliably safeguard maximal functional diversity. Thus, phylogenetic diversity and functional diversity are related but still complementary. Priority setting exercises should use these metrics in combination to identify conservation targets.

Vertical stratification of bird community in Cikepuh Wildlife Reserve, West Java, Indonesia

Dinanti RV, Winarni NL, Supriatna J. 2018. Vertical stratification of bird community in Cikepuh Wildlife Reserve, West Java, Indonesia. Biodiversitas 19: 134-139. The complexity of heterogeneous strata can be used to determine the distribution of resources in bird communities. However, deforestation causes damage and may disturb the bird community in the forest. Cikepuh Wildlife Reserve in West Java, Indonesia is an example of degraded forest due to deforestation. Illegal logging in the area leads to approximately 7000 hectares of forest conversion into a plantation area. This study was conducted to test the hypothesis of the differences in the diversity of birds in each stratum of vegetation and the differences in the diversity of birds in forest and plantation. The study was conducted in March 2016. Point count method was used for bird surveys. The calculation of Shannon-Wiener diversity index showed that forest had a higher diversity of birds (Hʹ = 3.09) than plantation (Hʹ = 2.78). Based on the rank abundance graph, each vegetation stratum had a different type of curve. The middle canopy layer had the highest bird abundance while the emergent and understory layers had the lowest abundance.

Coffee management and the conservation of forest bird diversity in southwestern Ethiopia

Moist evergreen forests of southwestern Ethiopia host high levels of biodiversity and have a high economic value due to coffee production. Coffee is a native shrub that is harvested under different management systems; its production can have both beneficial and detrimental effects for biodiversity. We investigated how bird community composition and richness, and abundance of different bird groups responded to different intensities of coffee management and the landscape context. We surveyed birds at 66 points in forest habitat with different intensities of coffee management and at different distances from the forest edge. We explored community composition using detrended correspondence analysis in combination with canonical correspondence analysis and indicator species analysis, and used generalized linear mixed models to investigate the responses of different bird groups to coffee management and landscape context. Our results show that (1) despite considerable bird diversity including some endemics, species turnover in the forest was relatively low; (2) total richness and abundance of birds were not affected by management or landscape context; but (3) the richness of forest and dietary specialists increased with higher forest naturalness, and with increasing distance from the edge and amount of forest cover. These findings show that traditional shade coffee management practices can maintain a diverse suite of forest birds. To conserve forest specialists, retaining undisturbed, remote forest is particularly important, but structurally diverse locations near the forest edge can also harbour a high diversity of specialists.

Environmental characteristics drive variation in Amazonian understorey bird assemblages.

Tropical bird assemblages display patterns of high alpha and beta diversity and, as tropical birds exhibit strong habitat specificity, their spatial distributions are generally assumed to be driven primarily by environmental heterogeneity and interspecific interactions. However, spatial distributions of some Amazonian forest birds are also often restricted by large rivers and other large-scale topographic features, suggesting that dispersal limitation may also play a role in driving species’ turnover. In this study, we evaluated the effects of environmental characteristics, topographic and spatial variables on variation in local assemblage structure and diversity of birds in an old-growth forest in central Amazonia. Birds were mist-netted in 72 plots distributed systematically across a 10,000 ha reserve in each of three years. Alpha diversity remained stable through time, but species composition changed. Spatial variation in bird-assemblage structure was significantly related to environmental and topographic variables but not strongly related to spatial variables. At a broad scale, we found bird assemblages to be significantly distinct between two watersheds that are divided by a central ridgeline. We did not detect an effect of the ridgeline per se in driving these patterns, indicating that most birds are able to fly across it, and that differences in assemblage structure between watersheds may be due to unmeasured environmental variables or unique combinations of measured variables. Our study indicates that complex geography and landscape features can act together with environmental variables to drive changes in the diversity and composition of tropical bird assemblages at local scales, but highlights that we still know very little about what makes different parts of tropical forest suitable for different species.

Effect of forest composition on bird species abundance in tropical dry deciduous forest: A case of Bhimbandh Wildlife Sanctuary, India

Abstract. Khan MS. 2017. Effect of forest composition on bird species abundance in tropical dry deciduous forest: A case of Bhimbandh Wildlife Sanctuary, India. Biodiversitas 18: 78-85. The tropical dry deciduous forest (TDDF) with 38.2% of total forest cover in India forms the largest forest type of India. TDDF have been managed for centuries in the Indian subcontinent. However, so far it is not clear how different forest compositions and structures influence the abundance and the distribution patterns of faunal species vice versa. To provide further insights in this respect, we analysed how different habitat variables influence the abundance and diversity of forest birds. The difference in relative species abundances and habitat separation between forest specialist and generalist birds was also investigated. Different classes of bird density were discriminated with habitat variables. In general, it was found that higher bird densities were concentrated in the lower tree and shrub densities and diversities, however, high grass density and diversity with low tree density and diversity favoured the overall high bird density. Results further indicate the positive association of relative density of specialist bird species with the high grass density and diversity and low tree density and diversity. Specialists occurred in the lower relative densities (0.75±0.68) than that of generalists (0.86±0.69) and were found restricted to dense, pristine woody forest patches with high tree diversity.
 Keywords: Bhimbandh Wildlife Sanctuary, birds, Forest Composition, India, Tropical Dry Deciduous Forest

Plantation or natural recovery? Relative contribution of planted and natural pine forests to the maintenance of regional bird diversity along ecological gradients in Southern Europe

Forest plantations are increasingly used as tools to restore local biodiversity. Measures aimed at making plantations more complex and similar to natural forests to preserve biodiversity are still under debate. In this paper, we compare the role of natural and planted Pinus spp. for the maintenance of regional forest bird diversity along large-scale ecological gradients in Southern Europe. We modelled the relative contribution of the extent of either natural or planted pine forests to explain the richness of pine-dwelling forest birds in 3950 sample units (10km×10km cells) in peninsular Spain after controlling for the potential effects of geographical variables, environmental factors, surrounding land-uses, forest cover and vegetation structure within pine forests. Planted pine forests maintained less pine-dwelling forest bird species than did natural pine forests after controlling for confounding variables and structural differences. Such differences may be due to the time lags involved in forest bird community assembly. Regional and local drivers explaining the regional bird species richness varied among pine species, either natural or planted. Management recommendations to increase bird diversity should not be based on just mimicking natural pine forest structure as quickly as possible. Rather, specific practices should be developed locally together with the maintenance of unexploited natural stands for both reference and conservation of the results of the temporal component of community assembly.

How do diversity and functional nestedness of bird communities respond to changes in the landscape caused by eucalyptus plantations?

Studies of functional diversity can help to understand processes that determine the presence of species in different habitats. Measurement of functional diversity in silviculture areas is important because different functional traits can show different responses to this landscape alteration, and therefore ecological functions can be affected. This study evaluated functional and taxonomic differences in bird assemblages in a native forest and eucalyptus plantations, and also assessed the functional nestedness of the bird species. We censused birds in eucalyptus plantations of four different ages, and also in a native forest. The results showed higher functional and taxonomic diversity of birds in the native forest than in plantations and higher similarity of functional traits between plantations of different ages. The high functional diversity in the native forest indicates a greater variety of functional traits, resulting in greater functional complementarity than in plantations. The association of some traits with the native forest, such as nectarivory and foraging in air, indicates the importance of native habitats in maintaining species and functions related to such traits. Already, species traits in eucalyptus plantations represent a subset of those that were recorded in the native forest, indicating that some functions are maintained in plantations. Our results demonstrate that the species occurrence in the plantations and native forest is determined by species traits. Thus, the maintenance of some functions in plantations is provided, although there is a higher functional diversity in native forest.

Forest Cover and Bird Diversity: Drivers of Fruit Consumption in Forest Interiors in the Atlantic Forest of Southern Bahia, Brazil

Forest loss and fragmentation change the dynamics and structure of remnant populations, ultimately affecting key processes with implications for ecosystem functioning. Fruit consumption has important consequences for seed dispersal, maintaining the plant demography, which is also critical to the populations of animals that utilize them for resources. Therefore, understanding how forest cover reduction affects fruit consumption and, consequently, seed dispersal is essential to informing conservation policy for the remaining forest patches. This study was conducted in 20 forest sites with varying amounts of forest cover (from 6% - 85%) located in the Atlantic forest of southern Bahia, Brazil. We investigated whether forest loss and local bird diversity affected fruit consumption rates in the forest edge and interior. We used artificial fruit to estimate fruit consumption by birds. At each site, we set up 14 experimental stations, one located on the forest edge (∼3m) and the others in the forest interior (75...

SUBMONTANE FOREST AT BANTIMURUNG BULUSARAUNG NATIONAL PARK: HOTSPOT OF BIRD DIVERSITY AND ITS MANAGEMENT CONSERVATION

Submontane forest is considered as one of the biodiversity hotspot. Scientific information on bird diversity in this forest, however are lacking. The aim of this research was to find out submontane forest bird diversity and its conservation management. The research was carried out in three forests areas at Bantimurung Bulusaraung National Park submontane forest. Point Count method was used to observe bird population. Data were analyzed using Shannon-Weiner diversity index, Pielou Evenness index, Simpson dominance index, Margalef species richness index, and Sorensen Similarity index. The significance different between the number of individual bird was tested using Kolmogorov-Smirnov test. The result showed that submontane forest at Bantimurung Bulusaraung National Park is rich in bird diversity, bird endemic species and protected bird species. There was a significant different on the number of individual bird at several human disturbance levels. Based on these conditions, it is important to enhance understanding of the local people regarding zonation and develop cooperation with many stakeholders to increase the local community awareness concerning forest conservation. It is also necessary to ensure the sustainability of the National Park’s conservation program to maintain the submontane forest conservation.

Forest bird diversity and edge effects on three glade types at Mount Meru Game Reserve, Tanzania

This study examined the edge effects on forest bird diversity in five man-made, five upper natural and 15 lower natural glades in the Mount Meru Game Reserve, Tanzania from September 2005 to November 2005. Bird species composition differed significantly between the three glade types. Mountain Greenbul and Common Bulbul were indicators of forest edge habitat for upper natural and man-made glades, respectively. Bird total abundance, species richness and species diversity differed significantly with distance into the forest for all glade types, and decreased significantly with distance from the edge to the forest interior for man-made glades only. For upper natural glades, bird total abundance correlated positively with plant species richness and percentage basal cover for forbs. Most bird species strongly selected man-made glades over upper and lower natural glades, and strongly avoided upper natural glades. Habitat guilds in man-made glades were associated with foraging. Edge effects for all three glade types influenced bird total abundance and bird species composition, richness and diversity in the forest. In summary, forest glades and their edges have high conservation value for edge bird species. Therefore, clearing of the forest edges for man-made glades should continue in order to maintain these habitats for conservation purposes. Key words: Edge effects, forest birds, forest edge, forest glades, indicator species.