Biodiversity of diurnal breeding bird communities related to succession in the dry Douglas-fir forests of southeastern British Columbia

1994 ◽  
Vol 24 (10) ◽  
pp. 2034-2040 ◽  
Author(s):  
Francis E. Schwab ◽  
A.R.E. Sinclair
Keyword(s):  
Ponderosa Pine ◽  
Bird Species ◽  
Douglas Fir ◽  
Bird Communities ◽  
Breeding Bird ◽  
Successional Stage ◽  
Secondary Vegetation ◽  
Successional Stages ◽  
The Relationship ◽  
Successional Age

To determine the relationship between bird biodiversity and succession, we recorded the presence and approximate numbers of breeding diurnal bird species on plots representing secondary vegetation succession in an area classified as the very dry, hot subzone of the Interior Douglas-fir Biogeoclimatic Zone: grass, shrub, young conifer, and mature Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco)–ponderosa pine (Pinusponderosa Dougl. ex Laws.) forest. The number of species and individual birds increased with the successional age of plots, but young conifer plots had fewer bird species and individual birds than the preceding shrub stage. That is, succession produced peaks in bird biodiversity at the shrub and climax stages. All successional stages, with the exception of young conifer, possessed unique bird species or species found predominantly in that successional stage.

Functional evenness of bird communities varies along the elevational gradient in Europe: Conservation implications

2019 ◽  
Author(s):  
Federico Morelli ◽  
Yanina
Keyword(s):  
Species Richness ◽  
Elevation Gradient ◽  
Bird Species ◽  
Elevational Gradient ◽  
Negative Association ◽  
Bird Communities ◽  
Breeding Bird ◽  
Bird Species Richness ◽  
Large Spatial Scale ◽  
Functional Evenness

ContextThe negative association between elevation and species richness is a well-recognized pattern in macro-ecology. ObjectivesThe aim of this study was to investigate changes in functional evenness of breeding bird communities along an elevation gradient in Europe. MethodsUsing the bird data from the EBCC Atlas of European Breeding Birds we estimated an index of functional evenness which can be assumed as a measure of the potential resilience of communities.ResultsOur findings confirm the existence of a negative association between elevation and bird species richness in all European eco regions. However, we also explored a novel aspect of this relationship, important for conservation: Our findings provide evidence at large spatial scale of a negative association between the functional evenness (potential community resilience) and elevation, independent of the eco region. We also found that the Natura2000 protected areas covers the territory most in need of protection, those characterized by bird communities with low potential resilience, in hilly and mountainous areas.ConclusionsThese results draw attention to European areas occupied by bird communities characterized by a potential lower capacity to respond to strong ecological changes, and, therefore, potentially more exposed to risks for conservation.

scholarly journals Breeding Bird Communities in a Naturally Fragemented Forest Ecosystem in Grand Teton National Park

1998 ◽  
Vol 22 ◽  
pp. 37-37
Author(s):  
Gregory Schrott
Keyword(s):  
Habitat Fragmentation ◽  
National Park ◽  
Bird Species ◽  
Bird Communities ◽  
Western North America ◽  
Breeding Bird ◽  
Grand Teton National Park ◽  
Bird Populations ◽  
Natural Processes

This project examined the bird species breeding in the morainal forests on the valley floor in Grand Teton National Park. These forests are very patchily distributed and range in size from less than 1 hectare to over 700 hectares, allowing for a unique opportunity to study the responses of the local bird species to a forest system that has been fragmented for centuries through natural processes. This information can be useful for predicting the potential long-term impacts of human-caused forest fragmentation on bird populations in western North America. Until quite recently very little was known of the tolerances of western forest bird species to habitat fragmentation and this project could represent an important step towards understanding their needs in this regard.

scholarly journals Breeding bird density does not drive vocal individuality

2012 ◽  
Vol 58 (5) ◽  
pp. 765-772 ◽  
Author(s):  
Daniel T. Blumstein ◽  
Douglas R. Mcclain ◽  
Carrie De Jesus ◽  
Gustavo Alarcón-Nieto
Keyword(s):  
Bird Species ◽  
Breeding Bird ◽  
Vocal Individuality ◽  
Point Counts ◽  
Bird Density ◽  
Significant Relationships ◽  
Social Variation ◽  
Independent Contrast ◽  
Information Statistic ◽  
The Relationship

Abstract Many species produce individually specific vocalizations and sociality is a hypothesized driver of such individuality. Previous studies of how social variation influenced individuality focused on colonial or non-colonial avian species, and how social group size influenced individuality in sciurid rodents. Since sociality is an important driver of individuality, we expected that bird species that defend nesting territories in higher density neighborhoods should have more individually-distinctive calls than those that defend nesting territories in lower-density neighborhoods. We used Beecher’s information statistic to quantify individuality, and we examined the relationship between bird density (calculated with point-counts) and vocal individuality on seven species of passerines. We found non-significant relationships between breeding bird density and vocal individuality whether regressions were fitted on species values, or on phylogenetically-independent contrast values. From these results, we infer that while individuality may be explained by social factors, breeding bird density is unlikely to be generally important in driving the evolution of individually-specific vocalizations.

A Cutting-Date Estimation Technique for Ponderosa Pine and Douglas Fir Wood Specimens

1997 ◽  
Vol 62 (2) ◽  
pp. 260-272 ◽  
Author(s):  
Stephen E. Nash
Keyword(s):  
Regression Analysis ◽  
Ponderosa Pine ◽  
Distribution Curve ◽  
Douglas Fir ◽  
Archaeological Sites ◽  
Estimation Technique ◽  
Archaeological Data ◽  
Uncritical Acceptance ◽  
A Site ◽  
The Relationship

The interpretation of noncutting tree-ring dates from archaeological sites often proves problematic, and many sites in the Southwest may be more securely dated if cutting dates can be reliably estimated. Analysis of 54 ponderosa pine and 46 Douglas fir specimens reveals that the relationship between heartwood and sapwood in these species is sufficiently structured that regression analysis can be used to estimate the number of sapwood rings, and by extension the tree's cutting date, on the basis of the number of heartwood rings present on wood specimens. The efficacy of this estimation technique is evaluated on samples from localized and well-dated proveniences at Walpi Pueblo, as well as in light of the aggregate date distribution curve for that site. Results suggest that uncritical acceptance of estimated cutting dates is ill advised, but that when cutting-date estimates (and their associated confidence intervals) are considered in light of contextualizing architectural and archaeological data, they may suggest alternative room construction and repair hypotheses. When considered as part of the aggregate date distribution for a site, estimated cutting dates may identify and augment date concentrations, thereby helping secure the chronometric placement of prehistoric sites in the Southwest.

scholarly journals Monitoring of Kilum-Ijim forest bird communities: initial findings

2003 ◽  
Vol 13 (3) ◽  
pp. 255-271 ◽  
Author(s):  
Philip F. Forboseh ◽  
Ernest C. Keming ◽  
Clement L. Toh ◽  
Innocent N. B. Wultof
Keyword(s):  
Structural Changes ◽  
Bird Species ◽  
Bird Community ◽  
Montane Forest ◽  
Bird Communities ◽  
Individual Species ◽  
Bird Abundance ◽  
The Status ◽  
Abundance And Diversity ◽  
The Relationship

The Kilum-Ijim forest is an excellent example of the ornithological riches of the Cameroon montane forest biome. The forest is also important to over 200,000 people who exert enormous pressure on the ecosystem. In 1995, the Kilum-Ijim Forest Project began systematic monitoring of birds, with the intention of using them as indicators of the overall condition of the forest, as well as monitoring the status of individual species. Analyses of data collected in 1999–2000 demonstrated some clear differences in habitat use, suggesting suites of bird species may be indicators of changes in vegetation. However, beyond this, little is known about the response of birds to habitat modifications, or the relationship between bird abundance and diversity of other organisms at Kilum-Ijim. It is argued that the objective of assessing changes in vegetation could be more satisfactorily pursued through direct measurement of structural changes in habitats. We highlight the necessity for a shift in the programme objectives to place greater emphasis on monitoring endemic and threatened bird species for their own status and on assessing changes in the bird community as a function of changes in the vegetation.

A habitat-based approach to determining the effects of drought on aridland bird communities

The Auk ◽  
2021 ◽  
Author(s):  
Samuel G Roberts ◽  
David P Thoma ◽  
Dustin W Perkins ◽  
Elizabeth L Tymkiw ◽  
Zachary S Ladin ◽  
...  
Keyword(s):  
Water Deficit ◽  
National Parks ◽  
Water Availability ◽  
Bird Species ◽  
The United States ◽  
Bird Communities ◽  
Habitat Types ◽  
Breeding Bird ◽  
Bird Density ◽  
Annual Water

Abstract Aridland breeding bird communities of the United States are among the most vulnerable to drought, with many species showing significant population declines associated with decreasing precipitation and increasing temperature. Individual breeding bird species have varied responses to drought which suggests complex responses to changes in water availability. Here, we evaluated the influence of water deficit, an integrative metric of drought stress, on breeding bird communities within 3 distinct aridland habitat types: riparian, pinyon-juniper, and sagebrush shrubland. We used 12 years of breeding bird survey data from 11 national parks and monuments in the Northern Colorado Plateau Inventory and Monitoring Network (NCPN). We used a multivariate community-level approach to test for the effect of annual water deficit on the bird communities in the 3 habitats. We found that bird communities responded to water deficit in all 3 habitat types, and 70% of the 30 species–habitat combinations show significant relationships between density and variation in water deficit. Our analyses revealed that the direction and magnitude of species responses to water deficit were habitat-dependent. The habitat-specific responses we observed suggest that the adaptive capacity of some species depends on the habitat in which they occur, a pattern only elucidated with our habitat-based approach. The direction and magnitude of the relationships between predicted densities and annual water deficit can be used to predict the relative sensitivity of species within habitat climate changes. These results provide the first attempt to determine how the indirect effect of changes in water availability might affect aridland breeding birds in distinct habitat types. Linking breeding bird density to annual water deficit may be valuable for predicting changes in species persistence and distribution in response to climate change.

Die Brutvogelfauna eines Nadelwaldes der nördlichen Voralpen nach dem Sturm Lothar

2017 ◽  
Vol 168 (2) ◽  
pp. 59-66
Author(s):  
Pierre Mollet ◽  
René Hardegger ◽  
Res Altwegg ◽  
Pius Korner ◽  
Simon Birrer
Keyword(s):  
Forest Succession ◽  
Coniferous Forest ◽  
Bird Species ◽  
Individual Species ◽  
Mountain Forest ◽  
Breeding Bird ◽  
Point Counts ◽  
Federal Institute ◽  
Central Switzerland ◽  
Bird Fauna

Breeding bird fauna in a coniferous forest in the northern Prealps after storm Lothar In a 70-hectare large coniferous forest located on the northern edge of the Alps in central Switzerland, Canton of Obwalden, at an altitude of 1260 to 1550 metres above sea level, we surveyed the local breeding bird fauna in 2002 and 2013 by means of point counts as well as additional area searches for rare species. In December 1999, hurricane Lothar caused two large windthrow areas and several smaller areas with scattered throws in the survey range. We found a total of 48 breeding bird species, which is a very diverse species composition for a mountain forest. In the eleven years between surveys, a decline in distribution or abundance was recorded for four species, while seven species showed an increase; a further four species showed no change. For the remaining species, the data sets were too small to reliably estimate changes. A comparison with forest structure data provided by the Swiss Federal Institute of Forest, Snow and Landscape Research WSL revealed that for five bird species, the changes in distribution or abundance could be explained at least partially by forest succession. In order to obtain realistic distribution and abundance values in this kind of breeding bird survey, it is essential to collect large enough samples and to consider the detection probability of each individual species using appropriate statistical methods.

scholarly journals Domain randomization-enhanced deep learning models for bird detection

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xin Mao ◽  
Jun Kang Chow ◽  
Pin Siang Tan ◽  
Kuan-fu Liu ◽  
Jimmy Wu ◽  
...  
Keyword(s):  
Deep Learning ◽  
Continuous Monitoring ◽  
Bird Species ◽  
Training Data ◽  
Learning Models ◽  
Fine Grained ◽  
Bird Detection ◽  
Relationship Of ◽  
The Relationship

AbstractAutomatic bird detection in ornithological analyses is limited by the accuracy of existing models, due to the lack of training data and the difficulties in extracting the fine-grained features required to distinguish bird species. Here we apply the domain randomization strategy to enhance the accuracy of the deep learning models in bird detection. Trained with virtual birds of sufficient variations in different environments, the model tends to focus on the fine-grained features of birds and achieves higher accuracies. Based on the 100 terabytes of 2-month continuous monitoring data of egrets, our results cover the findings using conventional manual observations, e.g., vertical stratification of egrets according to body size, and also open up opportunities of long-term bird surveys requiring intensive monitoring that is impractical using conventional methods, e.g., the weather influences on egrets, and the relationship of the migration schedules between the great egrets and little egrets.

scholarly journals Bird communities in a degraded forest biodiversity hotspot of East Africa

2021 ◽  
Author(s):  
Moses Mulwa ◽  
Mike Teucher ◽  
Werner Ulrich ◽  
Jan Christian Habel
Keyword(s):  
Tropical Forests ◽  
Agricultural Land ◽  
Bird Species ◽  
Bird Communities ◽  
Natural Forest ◽  
Tree Plantations ◽  
Agricultural Fields ◽  
Degraded Forest ◽  
Forest Patches ◽  
Small Forest

AbstractTropical forests suffer severe habitat destruction. Thus, tropical forests frequently consist today of only a few small remnants that are often embedded within a matrix of agricultural fields and tree plantations. Forest specialist species have experienced severe population declines under these circumstances. We studied bird communities based on census plots set up in a near-natural forest block, as well as degraded forest patches, tree plantations, and agricultural fields, across the Taita Hills in southern Kenya. We classified each bird species according its ecology and behavior. We quantified the land cover and landscape configuration around each census plot. Typical forest species were mainly observed in the near-natural forest block, and to a lower extent in degraded forest patches. Plantations were almost devoid of birds. Bird communities of small forest fragments were more similar to that of agricultural land than the near-natural forest block. Most frugivorous, insectivorous and nectarivorous birds occurred in forest habitats, while granivorous bird species dominated the bird communities of agricultural land. The surrounding landscape had a marginal impact on bird species composition at local sites. Our study showed that the preservation of near-natural cloud forest, including small forest patches, is essential for the conservation of forest-dependent species, and that plantations do not serve as surrogate habitats.

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