On large-scale dynamics and community structure in forest birds: lessons from some eucalypt forests of southeastern Australia

1995 ◽  
Vol 350 (1334) ◽  
pp. 369-379 ◽  

Models of ecological communities, including coevolved patterns of resource use among sympatric species (for example, ‘resource partitioning’), are poor or inadequate representations of natural systems despite intense theoretical effort for many years. Some of these difficulties are due to a failure to recognize the necessary conditions for community patterns to develop, which are largely controlled by the dynamic characteristics of individual species. In continental bird communities — examples of which are considered here - these necessary conditions often will not be met owing to the mobility of most species. Here I document the degrees to which the large-scale dynamics (over hundreds of km) of individual bird species are expressed in community terms in five forest-habitat types throughout the year. These data demonstrate that continental bird communities are so dynamic that the conditions for the development of definite structure are unlikely to be met in either proximate or evolutionary time. The failure of community theories to account for and predict structure probably reflects too much concentration on mechanisms at inappropriate spatial scales.

2003 ◽  
Vol 27 (2) ◽  
pp. 107-121 ◽  
Author(s):  
James W. Tucker ◽  
Geoffrey E. Hill ◽  
Nicholas R. Holler

Abstract The longleaf pine (Pinus palustris) ecosystem of the southeastern United States is among the most heavily degraded of all ecosystems. Less than 1% of the original longleaf pine forests remain as old-growth stands. Eglin Air Force Base (Eglin) in northwest Florida contains the largest remaining extent of longleaf pine, but much of this habitat has been degraded through fire suppression, selective logging, and planting off-site species of pines. We examined the distribution of bird species among habitats during spring and fall 1994–1995 to assess the influence of large-scale habitat restoration on bird communities across the landscape. During both spring and fall, species richness and relative abundance of neotropical migrants were greatest in oak hammocks and riparian habitats. During spring, the abundance of resident species was greatest in barrier island scrub and flatwoods, but species richness of residents also was high in oak hammocks. During fall, both species richness and abundance of residents were greatest in oak hammocks and flatwoods. Analyses of abundance for individual species (both neotropical migrants and residents) suggested that each habitat examined was important for ≥1 species. An analysis examining the importance of habitats for conservation found that oak hammocks and riparian habitats were important for species of high management concern, but burned sandhills along with oak hammocks and riparian habitats were very important for species of the greatest management concern. Our results suggest that habitat modifications resulting from restoration of the longleaf pine ecosystem will benefit many species of management concern. Bird species negatively affected by habitat modifications for longleaf pine restoration were abundant in other habitats. South. J. Appl. For. 27(2):107–121.


2013 ◽  
Vol 280 (1773) ◽  
pp. 20132495 ◽  
Author(s):  
Michael J. L. Peers ◽  
Daniel H. Thornton ◽  
Dennis L. Murray

Determining the patterns, causes and consequences of character displacement is central to our understanding of competition in ecological communities. However, the majority of competition research has occurred over small spatial extents or focused on fine-scale differences in morphology or behaviour. The effects of competition on broad-scale distribution and niche characteristics of species remain poorly understood but critically important. Using range-wide species distribution models, we evaluated whether Canada lynx ( Lynx canadensis ) or bobcat ( Lynx rufus ) were displaced in regions of sympatry. Consistent with our prediction, we found that lynx niches were less similar to those of bobcat in areas of sympatry versus allopatry, with a stronger reliance on snow cover driving lynx niche divergence in the sympatric zone. By contrast, bobcat increased niche breadth in zones of sympatry, and bobcat niches were equally similar to those of lynx in zones of sympatry and allopatry. These findings suggest that competitively disadvantaged species avoid competition at large scales by restricting their niche to highly suitable conditions, while superior competitors expand the diversity of environments used. Our results indicate that competition can manifest within climatic niche space across species’ ranges, highlighting the importance of biotic interactions occurring at large spatial scales on niche dynamics.


2019 ◽  
Vol 30 (1) ◽  
pp. 3-13 ◽  
Author(s):  
V. A. Gaychenko ◽  
T. V. Shupova

Changes in nesting conditions cause a change in the number of individual species, ecological groups, and, consequently, the structure of the bird community. The purpose of the study is to analyze the possibilities and directions – the transformations of the communitys of nesting birds in the process of reorganization of the forest ecosystem into a park. The material was collected in the territory of one of the forest parks in the Kiev city. Forest is an mixed based on Quercus robur L., Carpinus betulus L., Acer platanoides L., Tilia cordata L., Fraxinus excelsior L. There are individual trees Pinus Syvestris L. The territory of the forest park have different degrees transformed, and includes anthropogenic landscapes and forests plots that have been preserved almost in their natural state. Studies were conducted in the nesting period (April-June) 2012–2017. For analysis average data were used. The number and distribution of the birds were determined by the method of counting on the transects, in the 3 model plots. There are 71 species of birds of 11 orders. Of these, 63 species are nesting. The number of nested species of communities in model plots does not depend on the gradient of anthropogenic transformation, but a average density of nesting birds decrease: 2.91±0.66→2.54±0.67→2.10±0.48 pairs / km of the transect. Nesting birds are distributed between 9 faunogenetic complexes. Of these, in each model plot is represented by 8. Dominated by birds of the European nemoral complex. On the gradient of habitat transformation, a change in the fauna-genetic structure of bird communities in the direction of increasing the proportion of birds of the European nemoral and European forest-steppe complexes, birds of desert-mountain and tropical groups. Boreal and ancient species are superseded. Strengthening the transformation in forest plots, the distribution of birds in community on the ecological groups does change not much. But when the forest ecosystem is replaced by a park ecosystem, the proportion of sclerophiles increases 3–4 times. In all communities is dominated by woody nesters bird. On the gradient of transformation, the number of species of the tree canopies nesters birds (from 21 to 18), ground nesters birds (from 6 to 0), species that use many types of nesting stations (from 4 to 1) are decreases; the number of bird species that nesting in the buildings increases from 0 to 6, and the number of alien species from 0 to 4 (Streptopelia decaocto, Dendrocopos syriacus, Phoenicurus ochruros, Serinus serinus). In the park ecosystems, a decrease in the species composition of woodpeckers, does not entail a significant decrease in the species composition and abundance of secondary hollows nesters birds. Birds of the synanthropic subpopulations are nesting in cavities in park buildings. Most of the indices show an equivalent ά-diversity of all bird communities. The β-diversity of breeding birds during the transformation of the forest ecosystem into a park is reduced by half. Ranked distribution curves of the abundance of species are indicate abrupt changes in the balance of dominance-diversity in communities when a transformation are in the forest ecosystem. The dominant species pressure high are give in community, its abundance is 2.2–2.7 times higher than the abundance of the second species by the abundance. In a slightly transformed forest, this indicator is 1.1 times. Ranked curves of relative abundance of species are a more sensitive index of community transformation than data of indices by the dominance and of species distribution. The introduction into the forest ecosystem of even a small number of anthropogenic structures leads to a significant increase in the relative abundance of synanthropic birds. In our study, in to 2 times. On the gradient of the transformation the absolute number of nesting species of the synanthropic birds increases gradually: 30–33–36; the obligate synanthropic species more stronger: 0–2–7; the index of community synanthropization increases 1.5 times: 0.63–0.72–0.92.


2006 ◽  
Vol 36 (5) ◽  
pp. 1299-1318 ◽  
Author(s):  
Jim Schieck ◽  
Samantha J Song

Within boreal forests of western North America, the dominant large-scale natural disturbance is wildfire. Thus, harvesting that is as similar as possible to fire is expected to best maintain natural bird communities. We reviewed studies of birds (mainly grouse, woodpeckers, and songbirds) from boreal forests of western North America and conducted meta-analyses to compare the similarity of bird communities occurring postfire versus postharvest. We compared the bird communities at five seral stages and also summarized the effects of retaining large live trees at harvest. Bird communities immediately postharvest differed greatly from those postfire. Differences between disturbance types disappeared as the forest regenerated, and both disturbance types became dominated by relatively few bird species in 31- to 75-year-old forests. During the period 76–125 years postdisturbance, old-forest birds became present and bird species richness increased. However, the trajectory of forest succession during this period influenced bird communities; old aspen (Populus tremuloides Michx.), old mixedwood, and old white spruce (Picea glauca Moench (Voss)) forests all had different bird communities. Retention of large live trees in cutblocks resulted in their use by many old-forest birds, but results were not consistent among studies. Although most bird species had clear peaks in abundance in a specific forest type, no species with more than five detections was limited to a single forest type.


The Condor ◽  
2007 ◽  
Vol 109 (2) ◽  
pp. 237-255 ◽  
Author(s):  
John G. Blake

Abstract Species richness and composition of Neotropical forest bird communities vary spatially at both large and small scales, but previous comparisons based on 100 ha plots have not replicated plots within a region. I sampled birds in two 100 ha plots in lowland forest of eastern Ecuador to better understand how species richness and composition vary over smaller spatial scales. Birds were sampled in February and April of 2002–2005 (only in February in 2005). Plots were approximately 1.5 km apart in predominantly terra firme forest. A total of 319 species (285 and 281 per plot) from 43 families were represented in ~16 000 detections per plot; number of species and detections per sample averaged approximately 185 and 2300, respectively. Numbers of species and detections per family were strikingly similar in the two plots, but numbers of detections of individual species often differed, likely in response to differences in habitat between the two plots. Species richness and composition were similar in many respects to comparable data from Ecuador, Peru, and French Guiana, but differed from those of Panama. Differences were most pronounced at the species level, less at the genus level, and least when comparisons were based on families. Differences among sites in South America were correlated with geographic distance at the species and genus levels, but not at the family level. Results illustrate the value of replicated plots within a region for understanding how species richness and composition can vary at small spatial scales, and highlight the importance of beta diversity for determining overall patterns of regional diversity.


Botany ◽  
2020 ◽  
Author(s):  
James C. Lendemer ◽  
Jessica Coyle

Large-scale efforts to aggregate and promote the re-use of biodiversity data are leading to novel insights into biogeography and macroecology. However, secondary analyses must account for the tradeoffs and limitations of the original studies. Studies of speciose and taxonomically complex groups often utilize morphospecies or functional subsets as proxies, potentially complicating data re-use. We evaluated whether lichen biodiversity patterns are robust to differences in sampling methodology, utilizing parallel analyses to compare species richness, regional species pool variation, species probabilities of occurrence, and correlation of those three with environmental variables in data sets that cover the same geographic region. Analyses revealed that, although individual species distributions sometimes differed in idiosyncratic ways, inference based on the aggregated response of multiple species was generally robust across the two datasets, despite differences in observer expertise and functional and taxonomic scope. This suggests that biodiversity data assembled from disparate sources could be used to evaluate biogeographical and macroecological hypotheses in understudied groups such as lichens, particularly at larger spatial scales.


2020 ◽  
Vol 10 (7) ◽  
pp. 2382
Author(s):  
Angel David Pedroza ◽  
José I. De la Rosa ◽  
Rogelio Rosas ◽  
Aldonso Becerra ◽  
Jesús Villa ◽  
...  

A new technique based on the Band-Limited Phase-Only Correlation (BLPOC) function to deal with acoustic individual identification is proposed in this paper. This is a biometric technique suitable for limited data individual bird identification. The main advantage of this new technique, in contrast to traditional algorithms where the use of large-scale datasets is assumed, is its ability to identify individuals by the use of only two samples from the bird species. The proposed technique has two variants (depending on the method used to analyze and extract the bird vocalization from records): automatic individual verification algorithm and semi-automatic individual verification algorithm. The evaluation of the automatic algorithm shows an average precision that is over 80% for the identification comparatives. It is shown that the efficiencies of the algorithms depend on the complexity of the vocalizations.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Affan Nasruddin-Roshidi ◽  
Mohammad Saiful Mansor ◽  
Nor Adibah Ismail ◽  
Ehwan Ngadi ◽  
Mohd Izzat-Husna ◽  
...  

Abstract Background Habitat degradation is known to have a major impact on the composition of bird communities, yet how these communities recover following such disturbance is less understood. This study examined bird community changes from pre-logging to recovery over the course of habitat disturbance caused by the development of the Hulu Terengganu Hydroelectric Dam Project in Peninsular Malaysia, between 2007 and 2018. Bird surveys were conducted using point count observations and mist netting in the dam area from the pre-logging phase until the operation phase. Results It was observed that while bird species significantly declined after large-scale habitat clearance between the pre-logging and construction phases, they showed positive signs of recovery from the inundation to operation phases. These findings indicate that the bird community is still recovering, and the permanent loss of habitat required by most of the original species has not occurred, as evidenced by recolonisation. Bird species composition differed across phases due to varying habitat conditions. The turnover rate and immigration rate (recolonisation and newly recorded species) were higher between the construction and operation phases. It was also observed that insectivorous birds were more heavily affected than others by changes to the landscape, which highlights the versatility, survivability and tolerance of certain species to extreme disturbance and habitat modification. Conclusion Although the operation phase showed an incremental change in bird species richness due to recolonisation and newly recorded species, this value remains far from that of the pre-logging phase. We predict that bird species recovery will continue to increase for some time before reaching a plateau among the newly created islands, reservoir and catchment area of the dam.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2879 ◽  
Author(s):  
Victoria J. Dreitz ◽  
Lani T. Stinson ◽  
Beth A. Hahn ◽  
Jason D. Tack ◽  
Paul M. Lukacs

Future demands for increased food production are expected to have severe impacts on prairie biodiversity and ecosystem integrity. Prairie avifauna of North America have experienced drastic population declines, prompting numerous conservation efforts, which have been informed primarily by small-scale studies. We applied a large-scale perspective that integrates scale dependency in avian responses by analyzing observations of 20 prairie bird species (17 grassland obligates and three sagebrush obligate species) from 2009–2012 in the western prairie region of the United States. We employed a multi-species model approach to examine the relationship of land ownership, habitat, and latitude to landscape-scale species richness. Our findings suggest that patterns and processes influencing avian assemblages at the focal-scale (e.g., inference at the sampling unit) may not function at the landscape-scale (e.g., inference amongst sampling units). Individual species responses to land ownership, habitat and latitude were highly variable. The broad spatial extent of our study demonstrates the need to include lands in private ownership to assess biodiversity and the importance of maintaining habitat diversity to support avian assemblages. Lastly, focal-scale information can document species presence within a study area, but landscape-scale information provides an essential complement to inform conservation actions and policies by placing local biodiversity in the context of an entire region, landscape or ecosystem.


2021 ◽  
Author(s):  
Lucas P Martins ◽  
Daniel B Stouffer ◽  
Pedro G Blendinger ◽  
Katrin Bohning-Gaese ◽  
Galo Buitron-Jurado ◽  
...  

Species interactions can propagate disturbances across space, though ecological and biogeographic boundaries may limit this spread. We tested whether large-scale ecological boundaries (ecoregions and biomes) and human disturbance gradients increase dissimilarity among ecological networks, while accounting for background spatial and elevational effects and differences in network sampling. We assessed network dissimilarity patterns over a broad spatial scale, using 196 quantitative avian frugivory networks (encompassing 1,496 plant and 1,003 bird species) distributed across 67 ecoregions and 11 biomes. Dissimilarity in species and interactions, but not in network structure, increased significantly across ecoregion and biome boundaries and along human disturbance gradients. Our findings suggest that ecological boundaries contribute to maintaining the world's biodiversity of interactions and mitigating the propagation of disturbances at large spatial scales.


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