Bird Community Composition Research Articles

Breeding bird response to riparian forest management: 9 years post-harvest

We previously examined the 3-year response of breeding bird communities to timber harvest in riparian areas using two harvest techniques (full tree harvest (GPL) and cut-to-length (CTL)) along first- to third-order streams in northern Minnesota, USA. We revisited the same 12 sites 9 years post-harvest and compared community composition, total abundance, species richness, and the abundance of bird guilds on harvest plots randomly assigned to four treatments (three plots per treatment). Analyses revealed a significant response of the bird community to timber harvest in the riparian area. Nine years post-harvest, bird communities in the uncut riparian buffers were statistically indistinguishable from control bird communities. Differences in bird communities between CTL and GPL treatments detected 3 years post-harvest in buffers were no longer evident after 9 years. Breeding bird community composition in harvested buffers became more similar to uncut and control buffer communities in species composition. All treatment buffers continued to have more species and individuals than control buffers; these bird species had affinities for early-successional forests. No differences among forest interior species or ground-nesting birds were evident between treatments 9 years post-harvest.

Spatial distribution and habitat of the Anavilhanas Archipelago bird community in the Brazilian Amazon

This study is the first to present a quantitative survey of bird species occurring in the archipelago of Anavilhanas, located in the Rio Negro in the Brazilian Amazon and is part of the Anavilhanas Ecological Station. We asked whether bird community composition is similar among the islands, and between islands and areas dominated by the surrounding upland terra firme forest on the left (east) margin of the Rio Negro. The surveys were conducted in November and December of 1988, using two complementary methods with mist nets and boat transects. A total of 232 bird species was found for Anavilhanas including a survey done in 1998. The families Tyrannidae and Thamnophilidae showed the highest number of species (16.4% and 9.0% of the total respectively). Some species not well known or having limited distributions are relatively frequently encountered in the archipelago, such as Spizastur melanoleucus, Mitu tomentosa, Phaethornis rupurumii, Xiphorhynchus kienerii, Thamnophilus nigrocinereus, Myrmotherula klagesi, Myrmoborus lugubris, Pipra filicauda, and Cephalopterus ornatus. Hybrid Multidimensional Scaling (HMDS) ordination analysis indicated that the bird community composition is similar among islands. However, the bird community composition on the islands was significantly different from that in sites of terra firme forest at Rio Negro margins. Anavilhanas is a unique ecological system in the Amazon and has it own avifauna.

<div>Birds surveyed in the harvested and <span style="font-size: 10px;">unharvested areas of a reduced-impact logged </span><span style="font-size: 10px;">forestry concession, located in the lowland </span><span style="font-size: 10px;">subtropical humid forests of the Department of </span><span style="font-size: 10px;">Santa Cruz, Bolivia</span></div>

As part of a larger study of reduced-impact logging effects on bird community composition, we surveyed birds from December to February during the 2003-2004 wet-season within harvested and unharvested blocks of the La Chonta forestry concession, Department of Santa Cruz, Bolivia. The logged forest was harvested using reducedimpact logging techniques between one and four years previously. During point count surveys, we identified 5062 individual birds, belonging to 155 species, and 33 families. We provide a list of bird species found within the harvested and unharvested blocks of the concession for the benefit of other researchers assessing the responses of Neotropical avifauna to disturbance, and to facilitate increased understanding of the diverse bird assemblages found within the lowland subtropical humid forests of Bolivia.

DETERMINANTS OF LOCAL EXTINCTION AND TURNOVER RATES IN URBAN BIRD COMMUNITIES

Studying the effects of urbanization on the dynamics of communities has become a priority for biodiversity conservation. The consequences of urbanization are mainly an increased fragmentation of the original landscapes associated with a decrease in the amount of favorable habitats and an increased pressure of human activities on the remaining patches suitable for wildlife. Patterns of bird species richness have been studied at different levels of urbanization, but little is known about the temporal dynamics of animal communities in urban landscapes. In particular, urbanization is expected to have stronger negative effects on migratory breeding bird communities than on sedentary ones, which should lead to different patterns of change in composition. Using an estimation method accounting for heterogeneity in species detection probability and data collected between 2001 and 2003 within a suburban area near the city of Paris, France, we tested whether these communities differ in their local extinction and turnover rates. We considered the potential effects of patch size and distance to Paris' center as a measure of the degree of urbanization around the patches. As expected, local rates of extinction and turnover were higher for migratory than for sedentary species, and they were negatively related to patch size for migratory species. Mean species richness of the sedentary species increased during the study period and their local turnover rate was negatively related to the distance to the urban core, showing a trend to colonize the most urban patches. These results highlight the very dynamic nature of the composition of some local bird communities in fragmented habitats and help to identify factors affecting colonization and extinction.

NEOTROPICAL FOREST BIRD COMMUNITIES: A COMPARISON OF SPECIES RICHNESS AND COMPOSITION AT LOCAL AND REGIONAL SCALES

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 ...

Tree Diseases, Canopy Structure, and Bird Distributions in Ponderosa Pine Forests

We examined how canopy patterns at the landscape scale can influence bird community composition, abundance, or distribution. Our long-term goal is to determine how diseases and other small-scale disturbances that change canopy patterns influence bird distribution. Little is known about these relationships, partly because most measures of disturbance are based on timber production metrics. We developed a spatially dependent metric referred to as canopy closure roughness, which was significantly correlated to bird diversity on 4 ha sample plots, and used it to generate a spatial model showing the distribution of bird diversity at a resolution of 30 mover an area of 1 million acres (the entire Black Hills National Forest). Number of bird species per stand varied between 2 and 16. Number of species and bird diversity were positively related to intensity of tree cutting. Most common bird species were yellow-rumped warbler, dark-eyed junco, Townsend's solitaire, black-capped chickadee and red-breasted nuthatch. The spatial model of bird diversity showed clusters of high diversity at different locations within the forest. These methods may help lead to better tools for managing the linkages between specific disturbances and bird usage and enable more effective disturbance management by offering a platform for spatial planning.

The impact of high‐altitude ski‐runs on alpine grassland bird communities

Summary Treeless mountainous areas at high altitudes have increased in value as wildlife habitat, but they are affected and increasingly threatened by ski‐resort developments, in particular by the construction and enlargement of ski‐pistes. To assess the extent of this threat, we compared bird diversity and community composition in circular plots centred on (i) ski‐runs of recent construction, (ii) grassland habitats adjacent to ski‐runs and (iii) natural grassland habitats far from the ski‐runs. Plots located in natural grasslands supported the greatest bird species richness and diversity and the greatest grassland species density, whereas those set in ski‐pistes presented the lowest values. Plots located beside ski‐runs did not support smaller numbers of bird species and diversity than plots of natural areas, but they supported a significantly lower bird density. This suggests that ski‐pistes, besides exerting a negative direct effect on the structure of local bird communities, may also exert an indirect, detrimental effect on bird density in nearby patches. Generalized linear models showed that species richness and diversity, and abundance of grassland species were best modelled by combinations of factors, including habitat type (the three categories defined above) and altitude. The category ski‐run, in particular, was negatively correlated with species richness, diversity and abundance, and altitude was negatively associated with richness and diversity. Richness and abundance of arthropods were significantly lower in ski‐pistes than in the other plot types. Given that many invertebrates were preyed upon by birds, low food availability on ski‐runs may be one of the factors reducing the attractiveness of these patches to birds. Synthesis and applications. Retaining the avifauna around ski‐resorts is likely to involve developing new, environmentally friendly ways of constructing pistes, such as only removing rocks and/or levelling the roughest ground surfaces, to preserve as much soil and natural vegetation as possible. Restoration of ski‐pistes should promote the recovery and maintenance of local vegetation to enhance invertebrate and bird assemblages. In order to not compromise the safety of the ski‐runs, it may be necessary to control encroaching shrubs through pruning and/or cattle grazing.

Species richness of migratory birds is influenced by global climate change

ABSTRACTAim Global climate change is increasingly influencing ecosystems. Long‐term effects on the species richness and composition of ecological communities have been predicted using modelling approaches but, so far, hardly demonstrated in the field. Here, we test whether changes in the composition of bird communities have been influenced by recent climate change.Location Europe.Methods We focus on the proportion of migratory and resident bird species because these groups are expected to respond differently to climatic change. We used the spatial relationship between climatic factors and bird communities in Europe to predict changes in 21 European bird communities under recent climate change.Results Observed changes corresponded significantly to predicted changes and could not be explained by the effects of spatial autocorrelation. Alternative factors such as changes in land use were tested in a first approximation as well but no effects were found.Main conclusions This study demonstrates that global climate change has already influenced the species richness and composition of European bird communities.

How resilient are Andean montane forest bird communities to habitat degradation?

The threatened forest habitats of the tropical Andes are reportedly being modified and destroyed 30% faster than their lowland tropical counterparts, but impacts on the hyper-diverse resident avifauna have received little systematic study. We present a baseline analysis of the effects of habitat modification on birds in a lower montane forest landscape in Ecuador, comparing avian community composition in landscape elements subjected to different levels of human modification: primary forest, secondary forest, edge habitat and agricultural land. We use data from a point count survey of 300 counts at 150 sites to test whether community composition and density of birds with different reported habitat preferences and foraging strategies change among landscape elements. Species richness and diversity were lowest in agricultural land, but on some measures, equally low in primary forest. Richness and diversity peaked in secondary forest and edge habitat, but ordination and density analysis revealed clear differences in their species composition. While secondary forest contained mostly forest-preferring species, edge habitat harboured a mix of forest and open-land birds. There was a clearly structured gradient in species composition across landscape elements, with densities of habitat specialists, foraging guilds and families varying considerably from primary forest to agricultural land. Agricultural land was characterised by an assemblage of widespread, abundant species very different from that in core forest habitats. As such, while the majority of montane forest birds appear resilient to a certain level of habitat modification, they cannot persist, and are displaced, where forest has been cleared outright. We argue that, for Andean montane forests, preservation of mature secondary forest offers flexibility in supplementing preserved primary forest areas to provide sufficient habitat for the persistence of this incredibly diverse but severely threatened bird community.

Species composition and population fluctuations of alpine bird communities during 38 years in the Scandinavian mountain range

The breeding birds of four low alpine plots in Sweden were surveyed at Ammarnäs (65°50'N; two plots, each 100 ha, for 38 and 36 years), Abisko (68°18'; 130 ha, 12 years), and Anjan (63°45'; 150 ha, 11 years). Mean number of species of each plot was between 8 and 12 per year. Mean densities were between 37 and 89 pairs/ km2. Anthus pratensis was the most abundant species in all plots (33–52% of all pairs). Pluvialis apricaria had a mean density of between 3 and 4 pairs/km2 in all plots, hence a density that may be typical for very large mountain areas. Calcarius lapponicus, endemic to low alpine habitats, varied much between the plots, from 24 pairs/ km2 to none. Long-term trends at the Ammarnäs plots included increases of Pluvialis apricaria, Lagopus lagopus and L. mutus, and declines of Anthus pratensis, Eremophila alpestris, Gallinago media and Tringa glareola, but only that of E. alpestris being known to be more than local. The stable bird community accords well with the observed habitat stability.

Designing suburban greenways to provide habitat for forest-breeding birds

Appropriately designed, greenways may provide habitat for neotropical migrants, insectivores, and forest-interior specialist birds that decrease in diversity and abundance as a result of suburban development. We investigated the effects of width of the forested corridor containing a greenway, adjacent land use and cover, and the composition and vegetation structure within the greenway on breeding bird abundance and community composition in suburban greenways in Raleigh and Cary, North Carolina, USA. Using 50 m fixed-radius point counts, we surveyed breeding bird communities for 2 years at 34 study sites, located at the center of 300-m-long greenway segments. Percent coverage of managed area within the greenway, such as trail and other mowed or maintained surfaces, was a predictor for all development-sensitive bird groupings. Abundance and richness of development-sensitive species were lowest in greenway segments containing more managed area. Richness and abundance of development-sensitive species also decreased as percent cover of pavement and bare earth adjacent to greenways increased. Urban adaptors and edge-dwelling birds, such as Mourning Dove, House Wren, House Finch, and European Starling, were most common in greenways less than 100 m wide. Conversely, forest-interior species were not recorded in greenways narrower than 50 m. Some forest-interior species, such as Acadian Flycatcher, Hairy Woodpecker, and Wood Thrush, were recorded primarily in greenways wider than 100 m. Others, including ground nesters such as Black-and-white Warbler, Louisiana Waterthrush, and Ovenbird, were recorded only in greenways wider than 300 m. Landscape and urban planners can facilitate conservation of development-sensitive birds in greenways by minimizing the width of the trail and associated mowed and landscaped surfaces adjacent to the trail, locating trails near the edge of greenway forest corridors, and giving priority to the protection of greenway corridors at least 100 m wide with low levels of impervious surface (pavement, buildings) and bare earth in the adjacent landscape.

An Evaluation of the Contribution of Cultivated Allspice (Pimenta Dioca) to Vertebrate Biodiversity Conservation in Nicaragua

Tropical deforestation has emerged as one of the most important conservation challenges of our time, both because of the high species diversity and rates of endemism of tropical forests, and because of the rapid rate at which this process is proceeding. Recent studies indicate that areas of low-intensity agroforestry have similar levels of vertebrate diversity as some primary habitats, leading some researchers and conservationists to conclude that this type of commodity production could contribute to the conservation of biodiversity. We compared the composition of bird, mammal and herpetofaunal communities in primary forest, secondary forest, and pasture—and within the allspice productive systems that have replaced pasture. We found that mammal species richness was higher in primary forest than all other habitats; however for resident and migrant birds, amphibians and reptiles, species richness was similar between primary forest and the other habitats. Despite similarities in overall numbers of species, there were numerous species that were encountered only in primary habitats. We conclude that the cultivation of allspice in a mixed productive system can offset some of the losses to biodiversity; however it should be complemented by the establishment and maintenance of protected areas to accommodate populations of primary forest specialists that are unable to persist in altered habitats.

The Influence of Habitat Variables on Bird Communities in Forest Remnants in Costa Rica

This study examined the effects of forest structure (tree species richness, canopy height, percent canopy cover, understory density, tree density and DBH) and avian species traits (nest type and indicator list status) on the diversity, abundance and dissimilarity of bird communities in forest remnants and reforestation areas adjacent to Costa Rican banana plantations. Bird species richness and abundance were significantly related to tree species richness, canopy height and canopy cover in multiple linear regressions, the latter two forest structure variables being the best statistical predictors. Stratification of analyses by bird species indicator categories improved fits of regressions, because correlations with environmental variables differed in sign for different guilds of birds, a result likely to hold for other avifaunas. Analysis of avifauna dissimilarities among sites demonstrated that the species composition of bird communities was highly correlated with forest structure and tree species composition. Logistic regressions indicated that birds making protected (cavity, burrow, pendant, sphere and covered) nests were 2–6 times more likely to be present in the study avifauna than birds making open (cup, saucer, platform and scrape) nests and indicators of disturbed habitats were 11 times more likely to be present than indicators of primary forest. The forest structure data used were simple and inexpensive to collect, and data on avian traits were drawn from the literature. Thus, these methods could easily be replicated at other locations and would be valuable management aids and biodiversity assessment tools for conservation planning.

Distribution and abundance of forest birds in low-altitude habitat on Hawai'i Island: evidence for range expansion of native species

The Hawaiian honeycreepers are thought to be limited primarily to middle- and high-altitude wet forests due to anthropogenic factors at lower altitudes, especially introduced mosquitotransmitted avian malaria. However, recent research has demonstrated that at least one native species, the Hawai'i 'Amakihi (Hemignathus virens virens), is common in areas of active malaria transmission. We examined the current distribution and abundance of native and exotic forest birds within approximately 640 km2 of low-altitude (0–326 m) habitat on south-eastern Hawai'i Island, using roadside variable circular plot (VCP) at 174 stations along eight survey transects. We also re-surveyed 90 stations near sea level that were last surveyed in 1994–1995. Overall, introduced species were more abundant than natives; 11 exotic species made up 87% of the total individuals detected. The most common exotic passerines were Japanese White-eye (Zosterops japonicus), House Finch (Carpodacus mexicanus) and Northern Cardinal (Cardinalis cardinalis). Two native species, Hawai'i 'Amakihi and 'Apapane (Himatione sanguina), comprised 13% of the bird community at low altitudes. Hawai'i 'Amakihi were the most common and widespread native species, being found at 47% of stations at a density of 4.98 birds/ha (95% CI 3.52–7.03). 'Amakihi were significantly associated with 'ohi'a (Metrosideros polymorpha)-dominated forest. 'Apapane were more locally distributed, being found at only 10% of stations. Re-surveys of 1994–1995 transects demonstrated a significant increase in 'Amakihi abundance over the past decade. This work demonstrates a widespread recovery of Hawai'i 'Amakihi at low altitude in southeastern Hawai'i. The changing composition of the forest bird community at low-altitudes in Hawai'i has important implications for the dynamics of avian malaria in low-altitude Hawai'i, and for conservation of Hawai'i's lowland forests.

Spatial Variation of Bird Species in Landscapes Dominated by Old-growth Forests in Northern Boreal Finland

An important issue in conservation planning is to study the distribution and abundance patterns of species in natural landscapes. Information of concordant and clumped species distribution pattertns can enhance attempts to focus conservation efforts in sites/areas preferred by various species. We compared bird species abundance, community composition and species distribution patterns in three large old-growth forest areas (size 40–120 km2) in northern boreal Finland on the basis of quantitative bird censuses. Total bird density and species composition, and mean density and variances of the most abundant species were highly similar between the three areas. Most of the bird species were distributed randomly within the areas and species preferring old-growth forests showed compensatory density variation without preference for any sub-area. Mean density of species preferring old-growth forests was significantly higher in the studied large old-growth forests than in smaller old-growth forests and was about threefold higher than regional density of species in a predominantly managed landscape matrix. Bird species preferring old-growth forests are probably not dependent on a certain specific part of a virgin boreal forest landscape but rather on the overall size of the high-quality and diverse old-growth forest area.

Effects of an ENSO‐related fire on birds of a lowland tropical forest in Sumatra

AbstractComparisons of bird community composition in burned and unburned areas of a lowland tropical rainforest in Sumatra, Indonesia indicated the following during the first 5 years after burning: (1) original burn severity strongly affected bird community composition at both the genus and family levels; (2) bird community composition continued to change progressively away from immediate post‐burn composition in medium and severely burned forest as well as adjacent unburned forest; and (3) the degree of impact was both taxon and guild specific, with understory insectivores most detrimentally affected. Although species richness may temporarily increase in burned areas, this study suggests that multiple wildfires will lead to a decline in diversity over a large scale as birds of open fields replace interior forest specialists.

Response of breeding bird communities to forest harvest around seasonal ponds in northern forests, USA

We examined response of breeding bird communities to varying levels of timber harvest in and around 16-forested seasonal ponds in northern Minnesota, USA. This experimental study employed a before-after-control-impact design with three different harvest treatments. Treatments were assigned randomly ( n = 4 ponds/treatment) and were applied within 17 m wide buffers outward from the ponds’ edge: clear-cut harvest (reduction of basal area to <2 m 2/ha), partial cut harvest (reduction of basal area to 7–10 m 2/ha), and no harvest (no cut). Forest stands around treatment buffers ( n = 12) were clear-cut harvested (ranging from 6.5 to 12.5 ha). Ponds with no harvest in the adjacent forests (controls) or buffers surrounding the ponds ( n = 4) were maintained throughout the 5-year study. Prior to harvest, we found no significant difference ( P > 0.05) in bird community composition around seasonal ponds versus nearby forest habitat, suggesting that seasonal ponds do not affect bird community structure in a mature forest setting at this scale. Overall bird numbers and species richness increased ( P < 0.05) in all pond buffers compared to controls over the 4 years after harvest. Increases in bird numbers on treated versus control pond buffers were found across all migration and nesting guilds, and among the forest edge guild. Bird community species composition also changed within the treated versus control pond buffers after harvest. Differences in bird communities among treatments were small the first year after harvest, but continued to diverge from controls over the 4 years after harvest. Bird communities of the clear-cut treatment were most dissimilar to controls. Both the partial and no cut buffer bird communities were more similar to the control than the clear-cut treatment. Treated pond buffers had more birds associated with early successional habitat. In contrast, many interior forest-associated bird species did not occur in any of the buffers after harvest. We found no difference in breeding bird community composition between pond buffers and other residual patches left on harvested sites, but there was a significant difference between harvest treatments when we combined pond buffer and residual patch birds on each site. Early successional habitat-associated bird species were more abundant in residual patches on sites that had a clear-cut pond buffer and forest-associated species were more abundant in residual patches on sites with no cut pond buffers. Habitat for mature forest-associated bird species can be maintained on harvest sites by leaving no cut or partial cut buffers around seasonal ponds or in similar sized residual patches in other areas of the harvest.

Avifauna associated with ephemeral ponds on the Cumberland Plateau, Tennessee

ABSTRACT Although ephemeral ponds act as small hotspots of plant, invertebrate, and salamander diversity, the importance of such ponds for birds has been little studied. We hypothesized that ephemeral ponds on the Cumberland Plateau in Tennessee would support a greater abundance, richness, and diversity of birds than the surrounding hardwood forests. In 2004, we recorded all birds seen or heard in 10 min within 50-m radius circles at 25 ephemeral ponds. We repeated the counts at control sites located 150 m from each pond in the surrounding forest. To quantify potential food availability, we captured aerial invertebrates using sweep nets at four points around a subsample of eight ephemeral ponds and at an equal number of control sites. We found significantly greater bird abundance, richness, and species diversity at ephemeral ponds than at control sites, and that pond area was not associated with either bird abundance or richness. Bird community composition at pond and control sites was similar. Aerial invertebrates were significantly more abundant at ephemeral ponds than at adjacent forest sites, providing one possible explanation for greater bird abundance at ephemeral ponds.

A 16‐Year Study of Forest Disturbance and Understory Bird Community Structure and Composition in Tanzania

I compared understory bird community structure and composition among primary, slightly disturbed, and moderately disturbed forest in the East Usambara Mountains in Tanzania. Comparisons were conducted at two spatiotemporal scales: short term, conducted in 1999 and 2000, in which treatments (disturbance levels) were replicated, and long term, conducted from 1989-2004 along the same disturbance gradient of a subset of the short-term sites. I used capture-recapture models to assess the probability of detection and estimate species richness and population growth rates. The probability of detection of species did not vary significantly among disturbance levels but did vary significantly among species. Over the short- and long-term surveys, estimated species richness did not vary significantly among disturbance levels. Temporal variability in estimated species richness and the relative abundance of guilds did vary significantly among disturbance levels yet was contingent on survey length. The coefficient of variation in species richness over the short-term survey was <5% across all disturbance levels, whereas over the long-term survey it was 35% in slightly disturbed forest, 11% in moderately disturbed forest, and 0% in primary forest. In the short-term survey, zero of seven feeding guilds varied significantly in relative abundance among disturbance levels, whereas over the long-term survey four of seven (57%) feeding guilds did so. Terrestrial insectivores were most adversely affected by forest disturbance. Population growth rates (lamda) between 1989 and 2004 for the more common species of terrestrial insectivores did not vary significantly among disturbance levels and for these species were significantly < or = 1.00, indicating the recovery time for terrestrial insectivores in slightly and moderately disturbed forest is very long. These results illustrate the importance of long-term studies in assessing ecological impacts of forest disturbance and the importance of protecting primary forest in the Eastern Arc Mountains.

Trends in the Composition of Breeding Bird Communities: Anthropogenic or Climate Change Induced Process?

The article supports the hypothesis that the balance between anthropogenic and climate change-induced impacts on bird communities in the Baltic States has recently shifted towards a more pronounced climate impact. The results suggest that a climate warming-induced change in the composition of bird communities is not a universal process: it is a spatial and species-specific process. The article demonstrates that the impact of climate change on moist habitat birds is more dramatic than that on wetland, water and terrestrial birds. Birds of moist habitats predominate among the species with decreasing Lithuanian populations on the southern periphery of the species range. A list of affected bird species is presented and a new conception for more effective bird protection is introduced.