scholarly journals Acoustic community structure and seasonal turnover in tropical South Asian birds

2019 ◽  
Author(s):  
Anand Krishnan
Keyword(s):  
Community Structure ◽  
Phylogenetic Diversity ◽  
Species Turnover ◽  
Bird Community ◽  
Urban Ecosystems ◽  
Valuable Insight ◽  
Tropical Regions ◽  
Acoustic Community ◽  
Acoustic Space ◽  
Coexisting Species

AbstractBirds produce diverse acoustic signals, with coexisting species occupying distinct ‘acoustic niches’ to minimize masking, resulting in overdispersion within acoustic space. In tropical regions of the world, an influx of migrants from temperate regions occurs during winter. The effects of these migrants on acoustic community structure and dynamics remain unstudied. Here, I show that in a tropical urban bird community, the influx of winter migrants is accompanied by a turnover of the acoustic community. However, in spite of this turnover, the acoustic community remains overdispersed in acoustic niche space. The winter acoustic community additionally exhibits lower frequency-band diversity, consistent with species singing less continuously, as well as lower phylogenetic diversity. My data thus suggests that acoustic niches and community structure are stable across seasons in spite of species turnover. Migrants occupy similar regions of acoustic space as residents, and are relatively closely related to some of these species. Their arrival therefore leads to greater phylogenetic clustering in the winter, and thus lower phylogenetic diversity, although the acoustic community remains overdispersed. Studying seasonal dynamics of acoustic communities thus provides valuable insight into assembly processes, as well as a potential framework for long-term monitoring of urban ecosystems.

scholarly journals Acoustic community structure and seasonal turnover in tropical South Asian birds

2019 ◽  
Vol 30 (5) ◽  
pp. 1364-1374 ◽  
Author(s):  
Anand Krishnan
Keyword(s):  
Community Structure ◽  
Phylogenetic Diversity ◽  
Tropical Dry Forest ◽  
Bird Community ◽  
Urban Ecosystems ◽  
Dry Forest ◽  
Valuable Insight ◽  
Tropical Regions ◽  
Acoustic Community ◽  
Acoustic Space

Abstract Birds produce diverse acoustic signals, with coexisting species occupying distinct “acoustic niches” to minimize masking, resulting in overdispersion within acoustic space. In tropical regions of the world, an influx of migrants from temperate regions occurs during winter. The effects of these migrants on acoustic community structure and dynamics remain unstudied. Here, I show that in a tropical dry forest bird community occurring within an urban area in India, the influx of winter migrants is accompanied by a change in species composition of the acoustic community. However, in spite of this, the acoustic community remains overdispersed in acoustic niche space. The winter community of vocal birds at this study site additionally exhibits lower energy in the 4–7 kHz frequency bands (consistent with species singing less continuously), as well as lower phylogenetic diversity. My data are thus indicative of seasonal turnover in acoustic communities but suggest that acoustic niches and community structure are stable across seasons. Migrants occupy similar regions of acoustic space as residents and are relatively closely related to some of these species. Their arrival, therefore, leads to greater phylogenetic clustering in the winter and thus lower phylogenetic diversity, although the acoustic community remains overdispersed. Studying seasonal dynamics of acoustic communities thus provides valuable insight into assembly processes, as well as a potential framework for long-term monitoring of urban ecosystems.

scholarly journals Convergent acoustic community structure in South Asian dry and wet grassland birds

2020 ◽  
Author(s):  
Sutirtha Lahiri ◽  
Nafisa A. Pathaw ◽  
Anand Krishnan
Keyword(s):  
Community Structure ◽  
Phylogenetic Diversity ◽  
Grassland Birds ◽  
Northeast India ◽  
Signal Space ◽  
Dry Grasslands ◽  
Wet Grassland ◽  
Acoustic Community ◽  
Northwest India ◽  
Grassland Habitats

AbstractAlthough the study of bird acoustic communities has great potential to provide valuable conservation data, many aspects of their assembly and dynamics remain poorly understood. Grassland habitats in South Asia comprise distinct biomes with a unique avifauna, presenting an opportunity to address how community-level patterns in acoustic signal space arise. Similarity in signal space of different grassland bird communities may be due to phylogenetic similarity, or because different bird groups partition the acoustic resource, resulting in convergent distributions in signal space. Here, we quantify the composition, signal space and phylogenetic diversity of bird acoustic communities from the dry semiarid grasslands of Northwest India and the wet floodplain grasslands of Northeast India. We find that acoustic communities occupying these distinct biomes exhibit convergent signal space. However, dry grasslands exhibit higher phylogenetic diversity, and the two communities are not phylogenetically more similar than expected by chance. The Sylvioidea encompasses half the species in the wet grassland acoustic community, with an expanded signal space compared to the dry grasslands. Thus, dry and wet grassland communities are convergent in signal space despite differences in phylogenetic diversity. We therefore hypothesize that different clades colonizing grasslands partition the acoustic resource, resulting in convergent community structure across biomes. Many of the birds we recorded are highly threatened, and acoustic monitoring will support conservation measures in these imperiled, yet poorly-studied habitats.

Species turnover drives grassland community to phylogenetic clustering over long-term grazing disturbance

2019 ◽  
Vol 13 (2) ◽  
pp. 157-164
Author(s):  
Juntao Zhu ◽  
Yangjian Zhang ◽  
Wenfeng Wang ◽  
Xian Yang ◽  
Ning Chen ◽  
...  
Keyword(s):  
Community Structure ◽  
Species Composition ◽  
Phylogenetic Diversity ◽  
Species Turnover ◽  
Extreme Environments ◽  
Grazing Intensity ◽  
The Tibetan Plateau ◽  
Phylogenetic Community Structure ◽  
Grazing Disturbance

Abstract Aims Grazing exerts profound effects on grassland ecosystem service and functions by regulating species composition and diversity, and structuring community assembly worldwide. However, adaptions of phylogenetic diversity and phylogenetic community structure to long-term grazing disturbance remain poorly studied, especially for ecosystems distributed in extreme environments. Methods Here, we conducted an experiment with multigrazing intensities to explore the impacts of grazing disturbance on plant phylogenetic diversity and community structure in an alpine grassland of the Tibetan Plateau. Important Findings Grazing disturbance enriched plant species richness (SR), and stimulated species turnover from regional species pool, consequently changing community species composition. Under low intensities, grazing exerted no obvious effects on phylogenetic diversity and community structure, whereas communities changed from overdispersion to clustering under high grazing intensity. High grazing intensity resulted in stronger environmental filtering, which consequently selected those species with high resilience to grazing disturbance. The observed clustering structure was associated with the colonizing species which were closely related to resident species, and locally extinct species, and distantly related to residents. At the plant functional trait level, high grazing intensity increased species colonization largely by altering the effect of root depth on species colonization compared to light grazing. Our results highlight that solely utilization of SR and diversity cannot fully represent grassland communities responses to grazing. The effects of species turnover on community phylogenetic diversity and structure are entailed to be explored in the future grazing studies.

scholarly journals Drivers of avian species richness and community structure in urban courtyard gardens

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Alessandro Pirzio Biroli ◽  
Benjamin M Van Doren ◽  
Ada Grabowska-Zhang
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Urban Areas ◽  
Species Turnover ◽  
Model Averaging ◽  
Urban Ecosystems ◽  
Urban Ecosystem ◽  
Avian Species ◽  
Theoretic Approach ◽  
Ecosystem Research

Abstract Increasing global urbanisation has steered research towards understanding biodiversity in urban areas. Old city spaces throughout Europe have a proliferation of urban court gardens, which can create a mosaic of habitat pockets in an urban area. This article examines the patterns and drivers of avian species richness and community structure in 20 gardens of the constituent colleges of the University of Oxford. We conducted morning surveys across 7 weeks in May and June 2017 and used an information-theoretic approach and model averaging to identify important habitat predictors of species richness. We also studied community structure with Sorensen indices and non-metric multi-dimensional analysis. A total of 43 avian species were observed across all sites. Our sites generally differed in their avian assemblages, with greater species turnover than nestedness between sites. Site area was the strongest predictor of site species richness and surrounding habitat composition was the dominant driver of community structure. Thus, the largest gardens were the most species rich, but species composition among gardens differed based on the habitats in which they were embedded. We support using island biogeography theory to understand the avian species assemblages of urban ecosystems and stress the suitability of our study sites for future urban ecosystem research and generating wildlife awareness.

scholarly journals Convergent acoustic community structure in South Asian dry and wet grassland birds

Biology Open ◽  
2021 ◽  
Author(s):  
Sutirtha Lahiri ◽  
Nafisa A. Pathaw ◽  
Anand Krishnan
Keyword(s):  
Community Structure ◽  
South Asian ◽  
Phylogenetic Diversity ◽  
Grassland Birds ◽  
Northeast India ◽  
Signal Space ◽  
Dry Grasslands ◽  
Wet Grassland ◽  
Acoustic Community ◽  
Northwest India

Although the study of bird acoustic communities has great potential in long-term monitoring and conservation, their assembly and dynamics remain poorly understood. Grassland habitats in South Asia comprise distinct biomes with unique avifauna, presenting an opportunity to address how community-level patterns in acoustic signal space arise. Similarity in signal space of different grassland bird assemblages may result from phylogenetic similarity, or because different bird groups partition the acoustic resource, resulting in convergent distributions in signal space. Here, we quantify the composition, signal space and phylogenetic diversity of bird acoustic communities from dry semiarid grasslands of Northwest India and wet floodplain grasslands of Northeast India, two major South Asian grassland biomes. We find that acoustic communities occupying these distinct biomes exhibit convergent, overdispersed distributions in signal space. However, dry grasslands exhibit higher phylogenetic diversity, and the two communities are not phylogenetically similar. The Sylvioidea encompasses half the species in the wet grassland acoustic community, with an expanded signal space compared to the dry grasslands. We therefore hypothesize that different clades colonizing grasslands partition the acoustic resource, resulting in convergent community structure across biomes. Many of these birds are threatened, and acoustic monitoring will support conservation measures in these imperiled, poorly-studied habitats.

Bird community structure in natural and urbanized habitats along an altitudinal gradient in Pauri district (Garhwal Himalaya) of Uttarakhand state, India

Biologia ◽  
2012 ◽  
Vol 67 (4) ◽  
Author(s):  
Archana Naithani ◽  
Dinesh Bhatt
Keyword(s):  
Community Structure ◽  
Altitudinal Gradient ◽  
Diversity Index ◽  
Bird Species ◽  
Bird Community ◽  
High Elevation ◽  
Base Line ◽  
Natural Habitats ◽  
Forest Habitat ◽  
Rarefaction Analysis

AbstractIn the Indian subcontinent there is hardly any study that compares the bird community structure of urban/suburban areas with those of forest habitat. The present survey identified diverse assemblages of birds in the Pauri district at different elevations. A total of 125 bird species belonging to 40 families including two least count species (Lophura leucomelanos and Pucrasia marcolopha) were recorded during this survey in the forest and urbanized habitats of Pauri District (Garhwal Hiamalaya) of Uttarakhand state, India. The high elevation (Pauri 1600–2100 m a.s.l.), mid elevation (Srikot-Khanda 900–1300 m a.s.l.) and low elevation (Srinagar 500–900 m a.s.l.) contributed 88.8%, 63.2% and 58.4% of the total species respectively. Rarefaction analysis and Shannon diversity index showed that the high elevation forest habitat had highest bird species richness (BSR) and bird species diversity (BSD) followed by the mid and then the low elevation forests. BSR and BSD fluctuated across seasons at all elevations but not across habitat types. Present study provides a base line data about avian community composition in urbanized and natural habitats along altitudinal gradient in the study area. This information may be useful to the conservation biologists for the better management and conservation of the avifauna in the Western Himalaya, a part of one of the hot biodiversity spots of the world.

Bird community structure in native forest fragments and Acacia mangium plantations in Borneo

2018 ◽  
Vol 130 (1) ◽  
pp. 112 ◽  
Author(s):  
Alison R. Styring ◽  
Joanes Unggang ◽  
Alex Jukie ◽  
Ollince Tateh ◽  
Nyegang Megom ◽  
...  
Keyword(s):  
Community Structure ◽  
Acacia Mangium ◽  
Bird Community ◽  
Native Forest ◽  
Forest Fragments

scholarly journals Bird richness and composition in a Cerrado fragment in the State of São Paulo

2010 ◽  
Vol 70 (2) ◽  
pp. 243-254 ◽  
Author(s):  
LT Manica ◽  
M Telles ◽  
MM Dias
Keyword(s):  
Conservation Status ◽  
Bird Species ◽  
Low Frequency ◽  
Bird Community ◽  
Sao Paulo ◽  
The State ◽  
São Paulo ◽  
Conservation Area ◽  
Tropical Regions ◽  
Bird Richness

Bird species richness is an important measure for monitoring biodiversity changes. We analysed avifauna richness and composition in a 472 ha protected cerrado fragment and surroundings at Fazenda Canchim (RL-CPPSE), São Carlos, in the State of São Paulo (SP). We carried out 95.1 hours of observation (22 visits) at irregular intervals from May 2004 to December 2006. Qualitative surveys were done walking through tracks inside the fragment and on the roads at its edge. We recorded 160 species, six of which were endemic to Cerrado domain, 22 migratory, seven threatened within the State of São Paulo, and two globally threatened. We found 28 species in the cerradão, 110 in the cerrado sensu stricto, 13 in the gallery forest, 26 in the reservoir border, 26 in pasturelands and sugar cane monoculture and 55 in an anthropic area. Most of the species had low frequency of occurrence in all vegetation forms. Insectivores were the major trophic category (46.9%), which is typical in tropical regions, and it is also related to resource availability. Omnivores followed with 19.4%, granivores with 8.8% and frugivores with 7.5%. We conclude that, despite its size and conservation status, our study area has a remarkable bird community and must be considered as a priority conservation area to preserve bird species in Sao Paulo State.

scholarly journals Aboveground and belowground arthropod communities experience different relative influences of stochastic and deterministic assembly processes following disturbance

2016 ◽  
Author(s):  
Scott Ferrenberg ◽  
Alexander S. Martinez ◽  
Akasha M. Faist
Keyword(s):  
Community Structure ◽  
Stochastic Processes ◽  
Community Assembly ◽  
Tree Mortality ◽  
Species Turnover ◽  
Mineral Soil ◽  
Relative Influence ◽  
Subalpine Forest ◽  
Arthropod Community ◽  
Arthropod Communities

Background. Understanding patterns of biodiversity is a longstanding challenge in ecology. Similar to other biotic groups, arthropod community structure can be shaped by deterministic and stochastic processes, with limited understanding of what moderates the relative influence of these processes. Disturbances have been noted to alter the relative influence of deterministic and stochastic processes on community assembly in various study systems, implicating ecological disturbances as a potential moderator of these forces. Methods. Using a disturbance gradient along a 5-year chronosequence of insect-induced tree mortality in a subalpine forest of the southern Rocky Mountains, Colorado, USA, we examined changes in community structure and relative influences of deterministic and stochastic processes in the assembly of aboveground (surface and litter-active species) and belowground (species active in organic and mineral soil layers) arthropod communities. Arthropods were sampled for all years of the chronosequence via pitfall traps (aboveground community) and modified Winkler funnels (belowground community) and sorted to morphospecies. Community structure of both communities were assessed via comparisons of morphospecies diversity and assemblages. Assembly processes were inferred from a mixture of linear models and matrix correlations testing for community associations with environmental properties, and from null-deviation models calculated from observed vs. expected levels of species turnover (Beta diversity) among samples. Results. Tree mortality altered community structure in both aboveground and belowground arthropod communities, but null models suggested that aboveground communities experienced greater relative influences of deterministic processes, while the relative influence of stochastic processes increased for belowground communities. Additionally, Mantel tests and linear regression models revealed significant associations between the aboveground arthropod communities and vegetation and soil properties, but no significant association among belowground arthropod communities and environmental factors. Discussion. Our results suggest context-dependent influences of stochastic and deterministic community assembly processes across different fractions of a ground-dwelling arthropod community following a disturbance. This variation in assembly may be linked to contrasting ecological strategies and dispersal rates within above- and below-ground communities. Our findings add to a growing body of evidence indicating concurrent influences of different processes in community assembly, and highlight the need to consider potential variation across different fractions of biotic communities when testing community ecology theory.

scholarly journals Environmental conditions alter successional trajectories on an ephemeral resource: a field experiment with beetles in dead wood

Oecologia ◽  
2020 ◽  
Vol 194 (1-2) ◽  
pp. 205-219
Author(s):  
Ole Petter Laksforsmo Vindstad ◽  
Tone Birkemoe ◽  
Rolf Anker Ims ◽  
Anne Sverdrup-Thygeson
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Ambient Temperature ◽  
Dead Wood ◽  
Species Turnover ◽  
Experimental Studies ◽  
Developmental Rate ◽  
Fungal Community Composition ◽  
Species Richness And Abundance ◽  
Ephemeral Resources

Abstract Successional processes can be observed for many organisms and resources, but most studies of succession have focused on plants. A general framework has been proposed, advocating that successional patterns in species turnover are predominantly driven by competition, dispersal or abiotic limitation, and that the patterning of species accumulation over time gives clues to which process is most influential in a given system. We applied this framework to succession in communities of wood-living beetles, utilizing ephemeral resources in the form of 60 experimentally created dead aspen high stumps. High stumps were created at sun-exposed sites (high ambient temperature; favourable abiotic conditions) and shaded sites (low ambient temperature; abiotically limiting conditions). The sites were intermixed, ensuring similar dispersal opportunities. Beetle species richness and abundance were monitored with flight interception traps over four consecutive years. Consistent with predictions from the tested framework, several beetle functional groups accumulated species more slowly at the unfavourable shaded sites than at the favourable exposed sites. Species richness at the exposed sites increased rapidly to a plateau, consistent with a limiting effect of competition on community development. Similar results were obtained for beetle abundance and community structure. Part of the variance in beetle community structure was jointly explained by habitat and fungal community composition, suggesting that differences in the composition and developmental rate of fungal communities in the two habitats contributed to the observed patterns. Targeted experimental studies are now required to decisively establish what processes underlie the contrasting successional trajectories in the two environments.

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