Abundance Of Forest Birds Research Articles

Ptačí diverzita v historickém zámeckém parku – implikace pro ochranu biodiverzity v hospodářských lesích

Long-term trends of abundance and diversity of forest birds have been very stable over past decades in European managed forests. It can be caused by high heterogeneity on habitat scale. In European cultural landscapes, there is another habitat very similar to managed forests, and that is a historic manor park. The parks can even show higher bird diversity than managed forests. However, there is an evident knowledge gap related to long-term changes of bird abundance and diversity in the habitats of manor parks. In this study we observed long-term changes of bird community in the historic manor park Čechy pod Kosířem (Czech Republic) using comparison of bird territory mapping in 2022–2023 with older bird studies in this locality. We gained an overview of bird community changes in the manor park for the period of 1997–2023. Results show that the bird community in historic manor park was remarkably unvarying in abundance and diversity. Historic manor parks can be considered as important refuges for forest bird diversity in cultural landscapes. We discuss the research implications for conserving bird diversity in managed forests especially in connection with large old trees preservation providing heterogeneity of nest habitats.

Which Forest Characteristics Shape Bird Abundance in Central European Forests? A Case Study Based on Common Breeding Bird Survey in Czechia

Which Forest Characteristics Shape Bird Abundance in Central European Forests? A Case Study Based on Common Breeding Bird Survey in Czechia

Winged Wonders and Lush Landscapes: Exploring the Harmony between Birds and Forests

Birds are essential bio- or eco-engineers that play a vital role in regulating nature, and their interactions with other environmental aspects can be complex and varied. Forests and birds are intricately intertwined. Through their mutual interaction, they create a harmonious living system that supports both parties. Forest birds play a crucial role in maintaining the balance of nature by dispersing seeds, pollinating flowers, and controlling insect populations. In addition to housing and food, forests offer bird's places to nest, wintering grounds, and thermal refuges. The diversity and distribution of forest birds are critical indicators of forest health and ecosystem function. However, factors such as climate change, habitat loss and fragmentation, and human activities profoundly impact the distribution and abundance of forest birds. Addressing these issues and taking action to mitigate their effects is essential. The forest ecosystem and its avian inhabitants can be protected by restoring degraded habitats, putting conservation practices into place, and promoting sustainable forestry practices.

Effects of observer skill and survey method on forest bird abundance data: recommendations for citizen science conservation monitoring in the Caribbean

Effects of observer skill and survey method on forest bird abundance data: recommendations for citizen science conservation monitoring in the Caribbean

Sharing land via keystone structure: Retaining naturally regenerated trees may efficiently benefit birds in plantations.

Meeting food/wood demands with increasing human population and per-capita consumption is a pressing conservation issue, and is often framed as a choice between land sparing and land sharing. Although most empirical studies comparing the efficacy of land sparing and sharing supported land sparing, land sharing may be more efficient if its performance is tested by rigorous experimental design and habitat structures providing crucial resources for various species-keystone structures-are clearly involved. We launched a manipulative experiment to retain naturally regenerated broad-leaved trees when harvesting conifer plantations in central Hokkaido, northern Japan. We surveyed birds in harvested treatments, unharvested plantation controls, and natural forest references 1-year before the harvest and for three consecutive postharvest years. We developed a hierarchical community model separating abundance and space use (territorial proportion overlapping treatment plots) subject to imperfect detection to assess population consequences of retention harvesting. Application of the model to our data showed that retaining some broad-leaved trees increased the total abundance of forest birds over the harvest rotation cycle. Specifically, a preharvest survey showed that the amount of broad-leaved trees increased forest bird abundance in a concave manner (i.e., in the form of diminishing returns). After harvesting, a small amount of retained broad-leaved trees mitigated negative harvesting impacts on abundance, although retention harvesting reduced the space use. Nevertheless, positive retention effects on the postharvest bird density as the product of abundance and space use exhibited a concave form. Thus, small profit reductions were shown to yield large increases in forest bird abundance. The difference in bird abundance between clearcutting and low amounts of broad-leaved tree retention increased slightly from the first to second postharvesting years. We conclude that retaining a small amount of broad-leaved trees may be a cost-effective on-site conservation approach for the management of conifer plantations. The retention of 20-30 broad-leaved trees per ha may be sufficient to maintain higher forest bird abundance than clearcutting over the rotation cycle. Retention approaches can be incorporated into management systems using certification schemes and best management practices. Developing an awareness of the roles and values of naturally regenerated trees is needed to diversify plantations.

A multi-scale assessment of habitat disturbance on forest animal abundance in South American temperate rainforests

Anthropogenic disturbance has dramatically degraded and reduced the extension of the temperate rainforests of southern South America, negatively affecting forest animals that depend on habitat attributes at local and landscape scales. We conducted a multi-scale assessment (from 1 to 4000 m) to understand better how local and landscape attributes influence forest animal abundance in an anthropogenic disturbance gradient. We selected five forest-dependent animal species to assess the effects of habitat alteration: an arboreal marsupial (Dromiciops gliroides) and four forest birds (Pteroptochos tarnii, Scytalopus magellanicus, Scelorchilus rubecula, and Sylviorthorhynchus desmursii). We recorded forest animal abundances in four different habitat types (old-growth native, secondary, and logged native forests and forestry plantations). We measured local attributes in the field and characterized landscape attributes remotely. We evaluated marsupial abundance using camera traps and forest bird abundance using point counts, which were analyzed with Generalized Linear Mixed Models. Locally, canopy cover positively predicted marsupial abundance, while the number of fallen logs positively predicted bird abundance. At the landscape scale, native forest cover positively affected marsupial abundance, with significant effects at all levels. Conversely, plantation cover negatively affected forest bird abundance, while landscape heterogeneity negatively affected both groups. Our results showed that the abundance of the forest animals assessed here depends on multi-scale determinants. At the local scale, we advise greater canopy cover and maintaining woody debris. On the landscape scale, maintaining native forest cover should prioritize biodiversity management in the southern South America temperate forests. It is also crucial to control the expansion of forest plantations and reduce forest fragmentation to guarantee the persistence of forest-dependent species.

Habitat provision is a major driver of native bird communities in restored urban forests.

Urbanization, and the drastic loss of habitat it entails, poses a major threat to global avian biodiversity. Ecological restoration of urban forests is therefore increasingly vital for native bird conservation, but control of invasive predators may also be needed to sustain native bird populations in cities where species invasions have been particularly severe.We evaluated restoration success by investigating changes in native bird communities along a restoration chronosequence of 25 restored urban forests representing 72 years of forest development, which we compared to two target reference systems and a control system. We hypothesized that total species richness and relative abundance of native forest birds would increase with the age of restoration planting. We further hypothesized that relative abundance of rats, possums and cats would negatively impact native birds, while amount of native forest in the surrounding landscape would have a positive effect.We used structural equation modelling (SEM) to investigate the relative influence of forest structure (complexity index, tree height, canopy openness, basal area, species richness and density), landscape attributes (patch area, perimeter length, landscape composition within three buffer zones, distance to the nearest road and water source) and invasive mammalian predator indices of relative abundance on total species richness and relative abundance of native forest birds.Species richness increased with age of restoration planting, with community composition progressing towards that found in target reference systems. SEM revealed that years restored was a direct driver of bird species richness but an indirect driver of abundance, which was directly driven by canopy openness. Contrary to our predictions, invasive mammals had no significant effect on native bird species richness or abundance.Our results demonstrate that provision and improvement of habitat quantity and quality through restoration is the vital first step to re‐establishing native forest bird communities in cities.

Impact of Invasive Weeds on the Diversity and Dissimilarity of Bird Communities in Forested Areas

Caucasian hogweeds, mainly the Sosnowsky’s hogweed Heracleum sosnowskyi and the giant hogweed Heracleum mantegazzianum, create one of the most problematic plant invasions in the world. Due to their large size (weeds reaching 4–5 meters in height), they seem to be herbaceous plants that can threaten birds living in forest stands. This research quantified the structure and diversity of the forest birds’ community in forests with varying areas of invasive hogweeds located in south-eastern Poland. Changes in the accompanying non-forest birds’ community were also assessed. The study addressed the following questions: 1. How does the invaded area correlate with the abundance of forest birds? 2. How do communities and species respond to invaded vegetation? 3. How do the invading plants affect the various types of diversity of forest and non-forest birds? It turned out that both surveyed bird communities had a lower alpha diversity in invaded sites. Only forest birds, not able to change their location easily, formed a unique community (i.e., had a higher beta diversity) near invaders. Forest birds showed unchanged functional diversity based on the relative bird abundance and their connection, or lack of it, with the forest development phases. The effect of hogweeds on the abundance of forest birds was more negative in severely invaded areas with anthropogenic habitats. Non-forest birds showed higher species loss near the invasion, constant beta diversity and decreased functional diversity. This study is important as the forest is a climax community in the temperate zone, and unused open areas become spontaneously overgrown with young forests. Weeds disseminating after crop abandonment can highly and commonly affect forest and non-forest bird communities co-occurring in this type of overgrowing area.

Potential of Forest Bird Diversity and Abundance in Tretes Waterfall, Wonosalam as an Avitourism Location

Tretes Waterfall is an avitourism area because it is located in the Raden Soerjo Grand Forest Park area. The diversity of bird species is very abundant there, especially forest birds. The diversity and abundance of birds are influenced by the condition of the forest which is still beautiful and the availability of various types of trees and other living things as a source of food for a bird. The purpose of this research To analyze the potential diversity and abundance of forest birds in Tretes waterfall, Wonosalam as an avitourism location and Analyzing the carrying capacity of management as Tretes Waterfall, Wonosalam, an avitourism location. The study was carried out from June to September 2021. The method used is the IPA (Index Point of Abudance) method, namely bird data collection is carried out at a certain time where there are 4 observation points and the rapid assessment method. The species of birds found in Tretes Waterfall, Wonosalam were 45 species with the abundance value of bird species at the observation point of residential residents categorized as general. While the abundance of bird species at the observation points of post 1, post 2, and waterfalls is in the frequent category (2.1-10,0). Tretes Waterfall has the potential to be developed as an avitourism area. More in-depth research can be carried out to determine the spatial and temporal distribution of birds in Tretes Waterfall so that avitourism is easier to develop.

Current distribution and abundance of Kohala forest birds in Hawai‘i

Current distribution and abundance of Kohala forest birds in Hawai‘i

Meta-analysis shows that overabundant deer (Cervidae) populations consistently decrease average population abundance and species richness of forest birds

AbstractLocal-scale studies have shown that an overabundance of Cervidae species (deer, elk, moose) impacts forest bird communities. Through meta-analysis, we provide a generalized estimate of the overall direction and magnitude of the indirect effects overabundant cervids have on avian species. We conducted 2 distinct meta-analyses that synthesized data on 130 bird species collected from 17 publications. These analyses compared bird species’ population abundance and/or species richness at sites with overabundant cervids to sites with lower cervid abundance or without cervids. We evaluated whether the impacts of overabundant cervids are generally in the same direction (positive, negative) across avian species and locations and if effects vary in magnitude according to avian nesting location and foraging habitat. We found that where cervids were overabundant, there was a significant decrease in mean bird population abundance and species richness. Species that nest in trees, shrubs, and on the ground showed the largest decreases in abundance, as did species whose primary habitat is forest and open woodland and species that are primarily insectivores or omnivores. We did not find significant decreases in abundance for avian species that nest in cavities, whose primary habitat is grassland or scrub, nor for species that mainly eat seeds. Our results indicate that overabundant cervids, likely through their direct effects on vegetation and indirect effects on insects and forest birds, negatively impact individual bird populations and decrease overall avian species richness.

Effects of landscape context and vegetation attributes on understorey bird communities of cloud forest riparian belts

In recent decades land cover change resulting from different types of human activity has severely reduced the original area of tropical montane cloud forest (TMCF). Deforested landscapes in neotropical America commonly have a heterogeneous structure (i.e. landscape context) with increasingly small forest patches immersed in an agricultural matrix. Often, this matrix is not completely devoid of trees, but contain numerous and widely spread arboreal elements. Many of these elements are remnants of the original forest, such as arboreal riparian belts. In 14 riparian belts of TMCF in central Veracruz, Mexico, we assessed the relationship between the attributes of the bird community that uses these belts and their vegetation attributes, as well as with landscape structure in their vicinity at four different scales (within 250, 500, 750 and 1000 m). Bird richness and abundance in riparian belts were positively related with mean tree height. Regarding landscape context, the amount of urban area in the vicinity of each belt was positively related with bird abundance at the four scales studied, explaining between 14 and 31% of spatial variation. However, the abundance of forest interior birds was negatively related with urban area, explaining from 46 to 50% of variation. Both, local (tree height) and landscape characteristics (urban and forest cover) influence differentially bird abundance in riparian belts of cloud forest. Thus, both kinds of variables should be relevant for designing management plans aimed at enhancing the conservation of the native avifauna of the cloud forest and its ecosystem services within transformed landscapes.

Bird and small mammal community composition and abundance in upland open habitats and early conifer forests

Anthropogenic land-use change, such as commercial afforestation, is a significant driver of shifts in ecological communities and species abundance. In this study, the consequences of afforestation of upland habitats for two distinct animal groups, birds and small mammals, were examined by comparing open moorland, early pre-thicket conifer forests (2–4 years post-replanting) and late pre-thicket conifer forests (6–8 years post-replanting) across 24 upland study sites in Ireland. Field data were collected using bird point counts, live trapping of small mammals and detailed vegetation surveys. A total of 17 bird species and four small mammal species were detected. Both groups showed contrasting patterns of abundance between moorland and pre-thicket forests, with bird density being higher in moorland, while small mammal abundance was higher in pre-thicket forests. Bird diversity was lowest in moorland and highest in late pre-thicket forests, while small mammal diversity was highest in moorland and lowest in late pre-thicket forests. Our study shows that afforestation can alter the abundance and community composition of bird and small mammal populations and that the consequences of land-use change associated with afforestation in upland areas vary across different taxa. Our findings have important implications for forest management practices and conservation of upland habitats and species.

Factors responsible for forest and water bird distributions in rivers and lakes along an urban gradient in Beijing

Urban rivers and lakes, in combination with nearby green spaces, provide important habitat for urban birds, but few urban studies have focused on forest and water birds simultaneously along an urban intensity gradient. In this study, we randomly chose 39 rivers and lakes along an urban gradient of Beijing to examine bird community parameters in relation to aquatic and terrestrial habitat conditions, aquatic life data, and water quality data. We selected models with the AICc (corrected Akaike information criterion) method, bivariate linear or generalized linear regressions, and structural equation modeling to determine distribution patterns of avian communities along an urban gradient and bird-environment relationships. We found that both forest and water bird species and individuals peaked at intermediate urbanization intensities, especially for abundance of both forest and water bird and water bird species richness and abundance. We suggest that the differences in the strength of response to urbanization and the similarities in the gradient distribution pattern between forest and water birds should receive more attention in future urbanization gradient studies. Significant correlation ship between species richness of resident water birds, fish foragers, and insectivore-frugivores, abundance of insectivores, insectivore-frugivores (negative), and granivores (positive) and impervious surface proportion within 1-km radius buffer of sampled sites became more evident after coverage of artificial surfaces exceeded a 50% threshold. Regressions showed that distance from the urban center, number of islands in waterbody, and proportion of gross or unarmored shoreline length were significantly and positively related to species richness and abundance of both forest and water birds. The availability of unarmored shoreline is a critical pathway through which urbanization detrimentally impacts avian diversity. Our results demonstrate how the urban intensity gradient affects the relative availability of food resources and habitat, which could provide practical applications for urban landscape planning and avian biodiversity conservation in urban areas.

Can protected areas buffer short-term population changes of resident bird species in a period of intensified forest harvesting?

Protected areas (PAs) should maintain populations of focal species, but their ability to achieve this target is affected both by land use outside PAs and by climate warming. To study effects of land use on species and ability of PAs to maintain populations of species, we compared trends in abundance of 15 resident bird species between two periods of relatively stable and increasing logging volume in boreal forests in Finland, in 2006–2011 and 2012–2018, respectively. We studied trends in abundance of forest birds in unprotected areas and in PAs, where logging is not allowed. In general, patterns of population changes did not differ between PAs and unprotected areas. Abundances of ten of the 15 species were, however, concentrated in southern Finland, where PAs have low coverage, and where trends in abundance merely reflect changes in unprotected areas. Five species declined, and they all probably suffered from the effects of increased logging. Four of them had a southern distribution in Finland, so they should even benefit from the rapid climate warming occurring in these regions. In northern Finland, PAs cover a much higher proportion of land than in southern Finland, and thus PA network may better maintain populations, which was also reflected in more stable populations of species therein. For populations to persist in PAs and for PAs to buffer against environmental changes, a PA network should have a high level of coverage as in northernmost Finland thus supporting Aichi Target 11.

Changes in forest bird abundance, community structure and composition following a hurricane in Sweden

The effect that extreme natural events have on biological diversity is relatively poorly known. We used a before–after control‐impact (BACI) design to analyze changes in bird abundances and communities following Hurricane Gudrun, which struck southern Sweden in January 2005, felling 75 million m3 of forest and causing damage to 5% of forested areas (half a million hectares) in a few hours. We used recent measures of impact in combination with classical BACI contrasts to analyze bird count data from a monitoring program in Sweden. We investigated changes in the abundance of 17 species commonly found in forests, along with changes in species composition and functional structure of the bird community. In total, we considered 34 response variables and examined whether responses were immediate or long‐term. There was no evidence of a strong effect of the hurricane on the abundances of six species. Estimates of the effects on five species were too uncertain to draw inferences. We detected positive and negative effects of the hurricane on the abundances of the remaining six species, but the magnitude of effects often was small. Generally, the effects were in the expected direction: negative on birds associated with mature forest and positive on birds associated with open land or young forest. We found evidence of an increase in the proportion of species that nest on the ground and a decrease in the proportion of species that nest in cavities and trees. In contrast, the hurricane had no discernible effect on functional measures of diversity (richness, evenness or divergence), or on communities’ reproductive or morphological characteristics. Our results suggest that the hurricane affected bird populations and communities, but the magnitude of effects was generally small.

Effects of eucalyptus plantations on avian and herb species richness and composition in North-West Spain

Eucalyptus plantations have been established in many areas of the world due to their fast growth and profitability. In NW Spain, Eucalyptus plantations now cover a larger area than native forests. Although Eucalyptus plantations have been shown to affect biodiversity, relatively few studies have compared their effect on multiple taxonomic groups and different aspects of biodiversity. We compared herb and bird species richness and bird abundance between 14 paired patches of native deciduous forest and Eucalyptus plantations in a heterogeneous agro-forest region of NW Spain. We also investigated whether Eucalyptus plantations contribute to shifts in community composition by analysing species nestedness and turnover. We found that species richness of both herbs and birds was consistently lower in Eucalyptus plantations compared to native forests. Furthermore, the abundances of bird species characteristic of agricultural, forest, scrubland and other habitats, were all much lower in Eucalyptus plantations than in native forests. Herb and bird communities were also significantly dissimilar between the two habitats, but as a result of different ecological processes. Species turnover explained variation between habitats in herb composition, such that species present in native forests were typical for both farmland and forest habitats, whereas those present in Eucalyptus plantations were typical for scrub and farmland habitats. In contrast, bird assemblages showed a significant nested subset pattern, with fewer species in Eucalyptus plantations compared to native forests. In total, the relative abundance of cavity-nesting forest birds was at least 64% higher in native forests. Our results show that Eucalyptus plantations cannot replace native forests as they harbour different herb species and only a subset of the bird species found in native forests. Considering the current rate of increase of Eucalyptus plantations and the fragmentation of native forests in NW Spain, a lack of conservation of native forests could result in future loss of biodiversity in general and forest specialist species in particular.

Early post-fire bird community in European boreal forest: Comparing salvage-logged with non-intervention areas

Salvage logging after disturbances in forests substantially modifies vegetation structure and dead wood availability, but empirical evidence on its impact on biodiversity, especially in European boreal forest, is sparse. In this study we investigated the short-term effect of post-fire salvage logging on species richness and abundance of birds in recently burned mixed coniferous forest. Using point counts we estimated local species composition at 49 salvaged sites and 55 non-intervention sites (burnt forest left for natural regeneration) that were not logged after a fire in south-central Sweden. Local species richness, abundance and Simpson's species diversity index were significantly higher at non-intervention sites compared to salvaged sites. Forest birds that rely on structurally complex forest stands, such as tits (Parus major, Lophophanes cristatus, Poecile montanus), robin (Erithacus rubecula), mistle trush (Turdus viscivorus) and tree-toed woodpecker (Picoides tridactylus) were mainly associated with non-intervention sites, while species that are typically linked to farm- or shrublands, such as whinchat (Saxicola rubetra), white wagtail (Motacilla alba), red-backed shrike (Lanius collurio), and meadow pipit (Anthus pratensis) were more common at salvaged sites. These results are consistent with the idea that post-fire salvage logging has an immediate impact on the bird species composition and abundance in boreal forest. We conclude that although post-fire salvage logging may be beneficial for birds occurring in open landscapes, it has negative effects for forest bird species richness and abundance, at least over the short term. To protect typical forest communities with many forest specialists of high conservation concern, we recommend reducing the extent of post-disturbance salvaging in forests of high conservation value and updating the existing management policy to restore the amount of woody debris and facilitate long-term structural complexity and biodiversity in densely stocked conifer stands.

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.

Positive association between forest management, environmental change, and forest bird abundance

BackgroundThe global decrease in wildlife populations, especially birds, is mainly due to land use change and increasing intensity of land use (Parmesan and Yohe 2003). However, impacts of management tools to mitigate biodiversity loss at regional and global scales are less apparent in forest regions that have a constant forest area, and which did not suffer from habitat degradation, and where forests are sustainably managed, such as in Central Europe or the northeastern USA. A biodiversity assessment for Germany suggested, for example, that bird populations were constant (Bundesamt für Naturschutz 2015).ResultsThis study shows that changes in the environment and in forest management over the past 45 years have had a significant, positive effect on the abundance of non-migratory forest bird species in Central Europe. Economy (timber prices and GDP), forest management (timber harvest and mixed forest area), and environmental factors (atmospheric CO2 concentration and nitrogen deposition) were investigated together with changes in abundances of migratory and non-migratory forest birds using partial least squares path modeling. Climate change, resulting in longer seasons and milder winters, and forest management, promoting tree diversity, were significantly positively related to the abundance of non-migratory forest birds and explained 92% of the variation in their abundance in Europe. Regionally-migrating forest birds had stable populations with large variation, while birds migrating across continents declined in recent decades, suggesting significant, contrasting changes in bird populations in Europe. In northeastern North America we also found evidence that non-migratory forests have experienced long-term increases in abundance, and this increase was related to management. The increase of populations of non-migratory forest birds in Europe and North America is associated with an increase in structural diversity and disturbances at the landscape level.ConclusionsOur results suggest that reports about bird decline in forests should separate between migratory and non-migratory bird species. Efforts to mitigate the general decline in bird abundance should focus on land-use systems other than forests and support sustainable forest management independent of economic conditions.