Breeding Bird Communities Research Articles

On the breeding bird community of Wadi Al-Kharrar, Jordan Valley

The breeding birds of Wadi Al-Kharrar on the eastern banks of the Jordan River north of the Dead Sea comprise 35 species, whose frequency and density has been assessed. Blackbirds and Nightingales breed, at the edge of their breeding ranges, in a dense Tamarix thicket. Their density is very low compared to European habitats. The same is true for Reed Warblers which breed in the reed beds. A small population of Clamorous Reed Warbler (11 pairs) was found breeding, now representing the only site of this species in Jordan. Occurrences of the Indian Silverbill and of the Namaqua Dove indicate range extensions.

Breeding Bird Communities in Boreal Forest of Western Canada: Consequences of "Unmixing" the Mixedwoods

Breeding Bird Communities in Boreal Forest of Western Canada: Consequences of "Unmixing" the Mixedwoods

Breeding Bird Communities in Boreal Forest of Western Canada: Consequences of “Unmixing” the Mixedwoods

Abstract Silvicultural practices following clearcutting in boreal forest may encourage the creation of monospecific, single-aged stands having less vegetation heterogeneity and diversity than original stands. We conducted point counts in central Saskatchewan, Canada, 1993–1995, in pure and mixedwood stands dominated by black spruce (Picea mariana), jackpine (Pinus banksiana), trembling aspen (Populus tremuloides), or white spruce (Picea glauca). Mixedwood stands supported more individuals and more species than pure stands. Higher abundance in mixedwood stands relative to pure stands was consistent among nesting guilds and migration strategies. Rarefaction revealed similar patterns, although pure trembling aspen stands were predicted to support more species than aspen-dominated mixedwood stands. Increased avian diversity in mixedwood stands was not solely the result of the mixing of bird species associated with coniferous or deciduous forest types. Chipping Sparrow (Spizella passerina), Pine Siskin (Carduelis pinus), White-winged Crossbill (Loxia leucoptera), Red-breasted Nuthatch (Sitta canadensis), Swainson's Thrush (Catharus ustulatus), and Tennessee Warbler (Vermivora peregrina) were more abundant in mixedwood stands than pure stands. Black-throated Green Warbler (Dendroica virens), Magnolia Warbler (D. magnolia), and Blackburnian Warbler (D. fusca) were abundant in stands dominated by white spruce but were absent from jackpine or black spruce. Other species such as American Redstart (Setophaga ruticilla) and Chestnut-sided Warbler (D. pensylvanica) relied exclusively on pure trembling aspen, particularly stands with dense shrub cover. Several bird species in the boreal forest will be adversely affected by forestry practices that target mature to old aspen and white spruce mixedwoods and promote reduction in mixedwood compositions of regenerating stands.

Breeding Bird Abundance in Bottomland Hardwood Forests: Habitat, Edge, and Patch Size Effects

AbstractWe studied breeding bird communities in extensive bottomland hardwood forests along the lower Roanoke River in North Carolina during 1992 and 1993. We documented a rich avian community and recorded exceptionally high densities of two species (Prothonotary Warbler Protonotaria citrea, Acadian Flycatcher Empidonax virescens), as well as modest densities of three species rarely encountered elsewhere in the region (Cerulean Warbler Dendroica cerulea, Swainson's Warbler Limnothlypis swainsonii, American Redstart Setophaga ruticilla). The effects of patch size and edge on bird abundance were small in this forested landscape, but forest type had a large effect. We found half of the species analyzed to differ in abundance between the two primary habitat types, swamp forest and levee forest. In contrast, no species was consistently more abundant at patch interiors than near edges, and only two forest birds were more common in large compared with small patches. Species analyzed included permanent residents, short-distance migrants, Neotropical migrants, and those identified as forest-interior and area-sensitive species in other studies. Our results suggest that the Roanoke River bottomland forests may be functioning effectively as a reserve for a number of bird species.

Bird Communities Associated with Harvested Hardwood Stands Containing Residual Trees

Retention of residual trees in even-aged harvested stands is an alternative to traditional clearcutting, seed-tree, and shelterwood systems, but little is known about effects of new even-aged retention methods on bird communities. Clearcutting on Pennsylvania state forests recently has been replaced by a new forest-management practice termed even-aged reproduction stands with reservation guidelines (hereafter, EAR stands), in which high densities of trees in multiple crown and size classes (101 live trees/ ha ±28 SE on study sites) of both commercially and non-commercially important tree species are permanently reserved to maintain species and structural diversity. We compared habitat structure and breeding-bird communities between EAR stands (harvested) and reference stands (unharvested) in 2 state forests of Pennsylvania in 1997-98 and related bird abundance within harvested stands to differences in habitat characteristics among EAR stands and the surrounding landscapes. Total abundance of all bird species combined, abundances of early-successional and edge-habitat guilds, and abundances of many early-successional bird species were significantly higher in EAR stands than in reference stands, but abundances of the forest habitat guild and of 8 forest-associated species were lower in EAR stands. Although EAR stands provide suitable habitat for bird species associated with early-successional forests, abundances of species associated with mature forests were lower in EAR stands than in reference stands despite retention of residual trees. However, some species of forest birds (e.g., red-eyed vireos [Vireo olivaceus]), which usually are absent from recent clearcut stands until 12-20 years post-harvest, were often detected in EAR stands. Thus, residual trees in EAR stands provide to forest birds habitat components that are generally lacking in clearcut stands. Because abundances of both forest habitat and forest-canopy nesting guilds declined and abundance of brown-headed cowbirds (Molothrus ater) increased with size of EAR stands (especially when >20 ha), managers should consider limiting the size of EAR stands.

Effects of restoration techniques on breeding birds in a thermally-impacted bottomland hardwood forest

We evaluated the effects of revegetation techniques on breeding bird communities in a bottomland hardwood forest impacted by thermal effluent. In 1993, sections of the Pen Branch bottomland on the Savannah River Site, South Carolina, were herbicide-treated (glyphosate), burned, and planted; other sections were planted only while others were unaltered and served as controls. Few differences in the avian community occurred at 1 and 2 years post-treatment among treatments. Plots that were herbicide-treated, burned, and planted had greater species richness in 1994 and abundance in 1995 than sections that were planted only ( P<0.05). Bird species composition differed slightly among treatments and White-eyed Vireos ( Vireo griseus), Common Yellowthroats ( Geothlypis trichas), Indigo Buntings ( Passerina cyanea), and Red-winged Blackbirds ( Agelaius phoeniceus) were the most abundant species in the corridor. Revegetation techniques used to restore this thermally-impacted bottomland had little effect on the avian communities 1 and 2 years post-treatment.

Restoring Savanna Using Fire: Impact on the Breeding Bird Community

AbstractRestoration of many terrestrial plant communities involves the reintroduction of fire. However, there have been few studies of the effects of fire on the avifauna during the restoration process. To study the effects of oak savanna restoration on avian communities, breeding birds were censused and the vegetation structure documented in seven experimental burn units (8–18 ha) that had experienced different frequencies of controlled burns during the past 31 years (0–26 burns). Data were analyzed with both direct and indirect gradient analyses using multivariate techniques. The results showed that, as savanna restoration proceeded, there was a general decline in predominantly insectivorous species, particularly those that feed in the upper canopy region (leaves and air space), and a general increase in omnivorous species, particularly those that feed on the ground and in the lower canopy. Insectivorous bark gleaners (woodpeckers) also increased during restoration and were correlated with the increase in standing dead trees resulting from the fires. Overall, savanna restoration resulted in increases in the abundance of many open country bird species, including many species that have been declining in central and eastern North America, including red‐headed woodpecker, Baltimore oriole, eastern kingbird, vesper sparrow, field sparrow, lark sparrow, brown thrasher, American goldfinch, and brown‐headed cowbird. The shifts in species and guilds were correlated with changes in burn frequency and the macro vegetation structure—tree and shrub density, leaf area index, and relative proportion of standing dead trees. The findings show that savanna restoration can increase bird diversity and provide important habitat for uncommon or declining bird species. These birds are most likely attracted to one or more of the distinctive habitat features of the restored savanna environments, including scattered mature trees, standing dead trees and snags, and presence of both shrubby and grassland vegetation. The findings also suggest that restoration ecologists and wildlife biologists will need to work together to achieve desired goals, since different types of savanna restoration efforts may produce different effects on the breeding bird community.

The Relationships between Habitat Structure and Breeding Bird Communities in Deciduous Forest in Mid-eastern Korea.

The aim of this study was to examine the changes in breeding bird communities resulting from change in habitat structure caused by forestry. Research was conducted in a natural deciduous forest within the Pyoungchang national forest, Kangwon Province (N 37°27′, E 128°29′), in the Northeastern part of South Korea, from April to June, 1996. Three 8-ha areas with differing degrees of deforestation were selected for territory mapping of breeding bird communities. Vegetation characteristics, vertical structure of habitat (foliage height profile), and diameters at breast height (DBH) distribution were measured in each study area. The characteristics of the breeding bird communities and their niche relationships were surveyed. The relationships between habitat structure and breeding bird communities were also examined. The dominant tree species in the study area were Quercus mongolica, Ulmus davidiana, Acer mono and Fraxinus rhynchophylla. The vertical structure of the forest differed among the study areas. The number of trees per hectare, tree species diversity, and range of DBH decreased with the degree of forest cutting among the areas studied. Bird species diversity, breeding density, species richness, and guild structures also differed among study areas. The hole-nesting and canopyforaging guild was dominant in intact natural forest, whereas the bush-nesting and bush-foraging guild was found to be more prevalent at areas where a few trees had been felled. We found that the structure of a forest seems to be an important determining factor for a breeding bird community. Therefore, the interaction between the structure of a forest and its bird community should be considered in forest management for conservation of bird communities and their habitat.

Breeding bird communities in the beech forests of Mt. Moriyoshi

Breeding bird communities in the beech forests of Mt. Moriyoshi

The Relationships between Habitat Structure and Breeding Bird Communities in Deciduous Forest in Mid-eastern Korea

The Relationships between Habitat Structure and Breeding Bird Communities in Deciduous Forest in Mid-eastern Korea

Breeding Bird Community and Vegetation Structure in a Forest with a High Density of Sika Deer

Breeding Bird Community and Vegetation Structure in a Forest with a High Density of Sika Deer

BREEDING BIRD ABUNDANCE IN BOTTOMLAND HARDWOOD FORESTS: HABITAT, EDGE, AND PATCH SIZE EFFECTS

Abstract We studied breeding bird communities in extensive bottomland hardwood forests along the lower Roanoke River in North Carolina during 1992 and 1993. We documented a rich avian community and recorded exceptionally high densities of two species (Prothonotary Warbler Protonotaria citrea, Acadian Flycatcher Empidonax virescens), as well as modest densities of three species rarely encountered elsewhere in the region (Cerulean Warbler Dendroica cerulea, Swainson's Warbler Limnothlypis swainsonii, American Redstart Setophaga ruticilla). The effects of patch size and edge on bird abundance were small in this forested landscape, but forest type had a large effect. We found half of the species analyzed to differ in abundance between the two primary habitat types, swamp forest and levee forest. In contrast, no species was consistently more abundant at patch interiors than near edges, and only two forest birds were more common in large compared with small patches. Species analyzed included permanent residents...

Scrub-Successional Bird Community Dynamics in Young and Mature Longleaf Pine-Wiregrass Savannahs

We investigated how management for habitat conditions to support the endangered red-cockaded woodpecker effects the biodiversity of the breeding bird community associated with those habitats. Habitat is created by thinning, burning and mid-story control of hardwoods in mature longleaf stands. In addition, similar habitat structurally can be found in recently harvested areas. We tested the hypothesis that diversity and abundance, as well as survival and reproduction would be greater in mature stands. However, mature stands used for recruitment always had fewer species (36/31) than recently harvested areas (54/55). All species that occurred in recruitment stands also occurred in mature stands. No differences in survival rates were found between mature and recent cuts for Bachman's sparrow and indigo bunting.

Effect of alternative silvicultural systems on vegetation and bird communities in coastal montane forests of British Columbia, Canada

The montane alternative silvicultural systems (MASS) study was established to test the feasibility and ecological consequences of alternative silvicultural systems in montane old-growth forests of coastal British Columbia. The experiment includes replicated treatments representing a range of overstory removal (shelterwood, patch clearcut and green tree retention), adjacent old-growth and clearcut `control' areas and pre- and post-harvest measurement of a variety of ecological attributes. In this paper, we report results from vegetation and bird studies. Forest trees and understory vegetation were sampled on a series of permanent plots. Forest birds were monitored using transect methods during winter and point-counts during the breeding season. The cover, frequency and number of species of understory plants decreased after all harvesting treatments. Three years after harvest, cover increased in the harvested areas primarily due to herbaceous colonizers. The shelterwood, where understory vegetation was protected in undisturbed groups of leave trees, retained the greatest diversity of understory trees, shrubs and bryophytes compared to the other systems. Shelterwood species richness and abundance were greater 3 years after harvesting than before harvesting, but changes in species composition were quite variable. Presence of bryophytes and herbs that prefer moist, shaded habitats generally decreased after harvesting. Pre-harvest breeding bird communities were dominated by a few abundant species. Of 26 species detected, 4 species accounted for 64% of all bird detections, and 10 species accounted for 96%. Different levels of canopy retention produced dramatic effects on breeding birds. Species richness and bird abundance were reduced 3 years after harvesting. Most common species (9 species) showed evidence of population decline, 2 species showed significant increase, and 3 species showed unchanged abundance. Few species were completely lost or added to the avifauna. Only 17 species were recorded during winter surveys, of which 2 species accounted for the majority (68%) of detections. The vast majority (85%) of winter resident birds were concentrated in the old growth and the unlogged portions of patch-cut blocks.

Breeding bird communities in the beech forests of Mt. Hakamagoshi, peninsula Tsugaru

Breeding bird communities in the beech forests of Mt. Hakamagoshi, peninsula Tsugaru

Biodiversity in the floodplain of Saône: a global approach

Biodiversity of European floodplains is seriously threatened mainly due to (1) modifications of river courses such as channelisation or embankments, and (2) changes in traditional agricultural practices (i.e. usually pastures), into intensive production using drainage and fertilisation. A upstream-downstream survey of the Saone floodplain (France) has been done to identify the contribution of habitats to the floodplain biodiversity. Selected taxa were aquatic and terrestrial vegetation, Odonata, Coleoptera, Amphibians, and birds. The taxa were sampled in different habitat types that were: forests, grasslands and aquatic habitats. Tributary confluences with the river and cut-off channels contributed greatly to the floodplain diversity according to their invertebrates and aquatic vegetation communities. The abundance of rare species (benefitting of a national or regional protection status) was the highest in hygrophilous grasslands. Moreover, we demonstrated that diversity of breeding bird communities was correlated with the size of these habitats. We demonstrated also that alluvial forests contributed to maintain some particular species as Middle-spotted Woodpecker (Dendrocopus medius), while new plantations were colonized by openland bird communities sensible to the edge effect. Grassland fragmentation for agriculture appeared to be a major cause in biodiversity loss. Any alteration of the floodplain dynamics must be avoided to preserve the present diversity of riverine wetlands.

THE EFFECT OF VEGETATION MANAGEMENT ON BREEDING BIRD COMMUNITIES IN BRITISH COLUMBIA

Removal of deciduous vegetation in managed conifer forests is a major component of most silviculture programs in North America. We examined the effect of removing 90-96% of the volume of deciduous trees on breeding bird communities in young conifer plantations during four years. Trees were removed by two treatments: manual thin- ning (manual treatment), and manual thinning plus application of a herbicide, glyphosate (herbicide treatment). The control and two treatments were each replicated three times. During the three post-treatment years, the herbicide-treated sites remained depauperate of deciduous vegetation while the manually thinned sites experienced regrowth of deciduous trees. Number of species declined, total number of individuals increased, and common species dominated after herbicide treatment. Number of species, total number of individuals, and evenness increased after manual treatment. Turnover of bird species was highest in the herbicide-treated areas and lowest in control areas. Residents, short-distance migrants, ground gleaners, and conifer nesters increased significantly after herbicide treatment. De- ciduous nesters and foliage gleaners increased in abundance (nonsignificantly) in control and manually thinned areas. Warbling Vireos (Vireo gilvus), which are deciduous specialists, declined in areas treated with herbicide and may be particularly susceptible to glyphosate application. Although treated areas exhibited similar increases in the total number of birds, nesting success of open-cup nesting species was significantly lower in the herbicide-treated than in manually thinned areas. We suggest that habitat variability may be a mechanism for producing nested subset structure of bird community composition. Overall, the com- position of bird communities became more homogeneous after herbicide treatment, and it showed little change after manual thinning.

The Effect of Vegetation Management on Breeding Bird Communities in British Columbia

The Effect of Vegetation Management on Breeding Bird Communities in British Columbia

Breeding bird communities in pine plantations of the Spanish plateaux: biogeography, landscape and vegetation effects

Summary Afforestation with pines (Pinus pinaster and, to a lesser extent, P. pinea and P. halepensis) seems to be the most probable land‐use change over large areas of dry cereal croplands in central Spain in the next 10–20 years. This will be encouraged by changes in the subsidy policies of the Common Agricultural Policy that aim to decrease food production and restore the environmental diversity previously lost through agricultural intensification. This study addresses the factors influencing the richness and composition of breeding bird communities in these pine plantations and evaluates the potential environmental benefits of the afforestation programmes. The complement of bird species breeding in 88 plantations ranging in size from 0.1 to 6775 ha was determined. Plantations were characterized according to size, distance to the nearest large plantation, vegetation structure and geographical location (northern moist vs. southern xeric Iberian plateaux). Plantation size alone accounted for 67–75% of the variation in species richness, and was also the maintrait explaining the patterns of presence/absence of most individual bird species. Plantations smaller than 25 ha only maintained 50% of the regional pool of forest birds during breeding, whereas this proportion increased to 69–86% for plantations of 25–100 ha. Geographic location, degree of isolation and vegetation structure were also important. Bird species richness decreased with distance to a large plantation, and increased with prevalence of undergrowth shrubs and with plant species richness. Both species richness and the incidence of individual species in plantations were affected by geographical location. They were greater in plantations of the northern plateau, reflecting a trend of increasing densities of most forest bird species in Spain in more northerly locations. The results of this study suggest that re‐afforestation of former arable land in the Spanish plateaux is unlikely to increase species richness in forest bird communities. Given the regional scarcity of many forest birds and the small scale of new plantations, re‐afforestation schemes are unlikely to promote rich forest bird communities. Since plantations are unsuitable habitats for the bird species breeding in Spanish dry cereal croplands, and such birds have a high conservation value because of their small and declining populations the overall environmental benefits of large‐scale afforestation programmes will not include increased diversity of birds.

Influence of Gambel Oak on Breeding Birds in Ponderosa Pine Forests of Northern Arizona

Gambel oak (Quercus gambelii) is widely distributed in the Southwestern United States, where it frequently occurs in association with ponderosa pine (Pinus ponderosa). Fire suppression and fuelwood harvest likely have reduced oak abundance within the pine-oak type. Gambel oak occurs in multiple age-related growth forms, from small shrubs to large, old trees, and may provide important foraging and nesting habitat for breeding birds. I compared attributes of breeding bird communities in 16 northern Arizona ponderosa pine stands from 1993-1995, that were structurally similar except for the presence or absence of Gambel oak. Overlap in bird species composition was high; pine and pineoak stands had a mean Jaccard similarity value of 0.67. Five species were unique to pine stands, whereas 10 species were largely restricted to or only found in pine-oak stands. Overall bird diversity was significantly higher in pine-oak stands, which also had more species of Neotropical migrants, ground nesters, primary cavity excavators, and secondary cavity users than did pine stands. Pine and pine-oak stands had similar species evenness and similar rates of annual species turnover. Total bird abundance did not differ between cover types; however, primary cavity excavators were more abundant in pine-oak stands. Because of the apparent positive influence of oak on breeding birds, forest managers are encouraged to use treatments that retain and enhance the various growth forms of Gambel oak found in pine-oak stands.