Sagebrush bird communities differ with varying levels of crested wheatgrass invasion

2020 ◽  
Author(s):  
Sarah M Rockwell ◽  
Brian Wehausen ◽  
Pam R Johnson ◽  
Andrea Kristoff ◽  
Jaime L Stephens ◽  
...  
Keyword(s):  
Community Composition ◽  
Habitat Quality ◽  
Bird Species ◽  
Bird Communities ◽  
Individual Species ◽  
Native Grasses ◽  
Crested Wheatgrass ◽  
Trade Offs ◽  
Wide Range ◽  
Sagebrush Obligate

Sagebrush communities, covering millions of hectares in the western United States, are among our most imperiled ecosystems. They are challenged by various anthropogenic stressors, including invasion by non-native grasses, which degrade habitat quality and alter ecosystem function. Sagebrush restoration efforts are being undertaken to improve habitat conditions to benefit a wide range of sagebrush-dependent species. Because birds are good indicators of habitat quality, monitoring avian metrics is an effective way to measure progress of sagebrush restoration. We compared avian community composition and individual species abundance among three sagebrush-steppe habitat types with varying degrees of invasion by non-native crested wheatgrass Agropyron cristatum at the Camas National Wildlife Refuge in eastern Idaho. Sagebrush-obligate birds, such as sage thrasher Oreoscoptes montanus and sagebrush sparrow Artemisiospiza nevadensis, were most abundant in sagebrush habitats with an understory of native grass. Community composition was similar between sagebrush habitats with native and non-native grasses, but quite different from bird communities occupying crested wheatgrass. HABPOPS, a conservation planning tool, predicts that restoration of crested wheatgrass sites to sagebrush in poor or fair condition will increase the density of sagebrush-obligate bird species. Taken together, these results suggest that restoration of crested wheatgrass near-monocultures back to sagebrush will improve habitat value for much of the bird community whether or not the understory can be converted to primarily native grasses, or a mix of natives and non-natives. Of the sagebrush bird species of concern, Brewer’s sparrow Spizella breweri occupied sagebrush habitats with native vs. non-native understory at similar abundances, and this species could serve as a metric of intermediate restoration success. However, sagebrush sparrow and sage thrasher, which were significant indicators of sagebrush with native grasses, will likely benefit most from full restoration of a native herbaceous understory. Grassland-obligate birds like horned lark Eremophila alpestris and grasshopper sparrow Ammodramus savannarum were most abundant at crested wheatgrass-dominated sites and may not benefit from restoration back to shrubland; managers should understand potential trade-offs.

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 ◽  
Keyword(s):  
Large Scale ◽  
Necessary Conditions ◽  
Spatial Scales ◽  
Bird Species ◽  
Sympatric Species ◽  
Bird Communities ◽  
Individual Species ◽  
Ecological Communities ◽  
Individual Bird ◽  
Southeastern Australia

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.

scholarly journals Conserving native trees increases native bird diversity and community composition on commercial office developments

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Karen Dyson
Keyword(s):  
Community Composition ◽  
Environmental Gradients ◽  
Bird Species ◽  
Bird Community ◽  
Bird Communities ◽  
Bird Diversity ◽  
Bird Conservation ◽  
Tree Protection ◽  
Matrix Habitat ◽  
Site Use

Abstract In cities, woody vegetation provides critical shelter, nesting and foraging habitat for bird species of interest. Human actions—including development and landscaping choices—determine vegetation community composition and structure, making these choices critically important to urban bird conservation. A better understanding of how bird communities are impacted by parcel-scale actions can help guide policy and management best practices to improve matrix habitat quality and quantity. Here, I examined how bird habitat use varies along a vegetation gradient created by different development and landscaping choices. I surveyed 20 commercial office developments near Seattle in the Puget Trough region of Washington, USA selected using stratified random sampling, where I quantified bird communities and observed feeding behavior. I used GLMM and PERMANOVA models with data likelihood metrics to identify the best supported variables for bird site use, along with TITAN models to identify changes in community composition along environmental gradients. I found that measures of bird effective species richness and bird community are positively influenced by the presence of more native conifers, including the presence of a stand predating development and the height and density of native conifers. Measures of the native bird community are negatively influenced by higher non-native tree density. In contrast to prior research, top-down landscape-scale variables did not explain variation in measures of the bird community on office developments. Importantly, I found that birds are associated with the same habitat on office developments as observed elsewhere. Together, my findings suggest an important role for developers, land owners, landscape architects, and tree protection policy in bird conservation.

scholarly journals Transformation of the community of nesting birds in the process of reorganization of the forest ecosystem into a park

2019 ◽  
Vol 30 (1) ◽  
pp. 3-13 ◽  
Author(s):  
V. A. Gaychenko ◽  
T. V. Shupova
Keyword(s):  
Species Composition ◽  
Relative Abundance ◽  
Forest Ecosystem ◽  
Bird Species ◽  
Bird Communities ◽  
Individual Species ◽  
Natural State ◽  
Forest Steppe ◽  
Ecological Groups ◽  
Anthropogenic Landscapes

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.

scholarly journals Impacts of landscape-scale windthrow and subsequent, variable reforestation on bird communities in Central Europe

2020 ◽  
Author(s):  
Johannes Kamp ◽  
Johanna Trappe ◽  
Luca Dübbers ◽  
Stephanie Funke
Keyword(s):  
Norway Spruce ◽  
Community Composition ◽  
Central Europe ◽  
Tree Species ◽  
Secondary Succession ◽  
Forest Disturbance ◽  
Bird Species ◽  
European Beech ◽  
Bird Communities ◽  
Long Distance

AbstractWith climate change, the area affected by and the intensity of forest disturbances such as windthrow, insect outbreaks and fire will be increasing. Post-disturbance forest management will be varied, and it is difficult to predict how much natural succession will be allowed in comparison to reforestation. Both, disturbance and reforestation will affect forest biodiversity globally, but potential shifts in species distribution, abundance and community composition are poorly understood.We studied the response of breeding bird communities to windthrow and different reforestation strategies in one of Central Europe’s largest contiguous windthrow areas created by storm Kyrill in 2007. A decade after the disturbance, we compared bird species diversity, population densities and community composition on plots in replanted beech, replanted conifers and secondary succession (all salvage-logged after the storm), with undisturbed old Norway spruce Picea abies as a control, in the setting of a natural experiment.Of the stands blown down, 95% were Norway Spruce. Reforestation strategies varied, with Spruce and non-native conifers planted on twice the area that was replanted with European Beech Fagus sylvestris. Large areas were still dominated by successional tree species a decade after the storm, especially birch, mirroring recommendations of sub-national forestry agencies to include secondary succession in future forest development. Birds responded strongly to windthrow, with a pronounced community turnover. Species associated with high conifer stands reached significantly lower densities on sample plots in disturbed areas. Replanted areas were characterized by mostly ubiquitous bird species. Areas dominated by secondary succession, especially birch Betula spp., were characterized by high densities of long-distance migrants (often species of conservation concern) and shrubland species, among them several indicator species.Our results suggest that an increase of forest disturbance across Central Europe will lead to a pronounced reorganisation of biodiversity. Strategies that allow more secondary succession, and avoid replanting allochthonous tree species are likely to benefit populations of depleted bird species, even at salvage-logged and cleared disturbance sites.

scholarly journals Bird species richness in High-Andean forest fragments: habitat quality and topography matter

2020 ◽  
Vol 150 ◽  
Author(s):  
Constance Fastré ◽  
Diederik Strubbe ◽  
José A. Balderrama ◽  
Jennifer R.A. Cahill ◽  
Hannes Ledegen ◽  
...  
Keyword(s):  
Species Richness ◽  
Habitat Quality ◽  
Bird Species ◽  
Bird Communities ◽  
Forest Fragments ◽  
Bird Species Richness ◽  
Species Of Conservation Concern ◽  
Forest Remnants ◽  
Exotic Plantations ◽  
Conservation Concern

Montane forests worldwide are known centers of endemism and biodiversity but are highly threatened by fragmentation processes. Using data collected in 15 Polylepis forest remnants covering 2000 hectares, we investigated how bird species richness and bird community composition, particularly for species of conservation concern, are influenced by habitat quality and topography in the Tunari National Park in the High Andes of Bolivia. Bird species richness was highest in topographically complex, low-elevation Polylepis patches located in areas with a high potential to retain rainwater. Bird communities differed strongly between Polylepis lanata and P. subtusalbida remnants, each supporting different threatened and endemic species. Within the P. subtusalbida forest, high-elevation fragments characterized by high amounts of sunlight and low anthropogenic disturbance were more likely to contain threatened species. Surprisingly, we found no effect of fragment size on the diversity or composition of bird communities or the presence of bird species of conservation concern. The presence of exotic plantations (Pinus and/or Eucalyptus spp.) in or outside forest remnants was negatively associated with the number of bird species as well as with occurrence of the endangered Cochabamba-mountain finch (Compsospiza garleppi). To support the different communities found in Polylepis forests, these results suggest that conservation efforts should be directed towards both forest types (P. subtusalbida and P. lanata) present in the area. For an efficient management of avian diversity, exotic plantations should be established away from native remnants while existing patches should be managed to maintain or increase habitat quality. Finally, the importance of local topography in determining avian species richness and community composition in forest fragments, mainly through topographic controls on moisture distribution and the amount of sunlight received by the fragments, should be considered when planning conservation and reforestation schemes.

scholarly journals Longleaf Pine Restoration: Implications for Landscape-Level Effects on Bird Communities in the Lower Gulf Coastal Plain

2003 ◽  
Vol 27 (2) ◽  
pp. 107-121 ◽  
Author(s):  
James W. Tucker ◽  
Geoffrey E. Hill ◽  
Nicholas R. Holler
Keyword(s):  
Species Richness ◽  
Large Scale ◽  
Longleaf Pine ◽  
Bird Species ◽  
Pinus Palustris ◽  
Bird Communities ◽  
Selective Logging ◽  
Neotropical Migrants ◽  
Individual Species ◽  
Riparian Habitats

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.

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.

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.

Experimentally increased costs of parental care are shunted to offspring in species with extended care

2019 ◽  
Author(s):  
Gretchen F. Wagner ◽  
Emeline Mourocq ◽  
Michael Griesser
Keyword(s):  
Life History ◽  
Parental Care ◽  
Total Duration ◽  
Bird Species ◽  
Life History Strategy ◽  
Experimental Treatment ◽  
Cost Of Care ◽  
Adult Survival ◽  
Supporting Evidence ◽  
Trade Offs

Biparental care systems are a valuable model to examine conflict, cooperation, and coordination between unrelated individuals, as the product of the interactions between the parents influences the fitness of both individuals. A common experimental technique for testing coordinated responses to changes in the costs of parental care is to temporarily handicap one parent, inducing a higher cost of providing care. However, dissimilarity in experimental designs of these studies has hindered interspecific comparisons of the patterns of cost distribution between parents and offspring. Here we apply a comparative experimental approach by handicapping a parent at nests of five bird species using the same experimental treatment. In some species, a decrease in care by a handicapped parent was compensated by its partner, while in others the increased costs of care were shunted to the offspring. Parental responses to an increased cost of care primarily depended on the total duration of care that offspring require. However, life history pace (i.e., adult survival and fecundity) did not influence parental decisions when faced with a higher cost of caring. Our study highlights that a greater attention to intergenerational trade-offs is warranted, particularly in species with a large burden of parental care. Moreover, we demonstrate that parental care decisions may be weighed more against physiological workload constraints than against future prospects of reproduction, supporting evidence that avian species may devote comparable amounts of energy into survival, regardless of life history strategy.

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.

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