Dominant Bird Species Research Articles

ASSESSING THE HABITAT SUITABILITY OF TWO DIFFERENT ARTIFICIAL WETLAND HABITATS USING AVIAN COMMUNITY STRUCTURES

Artificial wetlands have become highly important habitat for a variety of bird species particularly waterbirds due to loss and degradation of natural wetlands. Avian community structures in two artificial wetland habitats i.e., man-made marsh and lake were investigated to identify the suitability of the habitats for avian species, habitat preference and food resources. Distance sampling point count method detected 35272 bird individuals of 98 species from July to November 2010. Ninty four bird species were recorded from man-made marsh and thirty one species from the lake area. Acridotheres tristis (6.34% of all detections) was the most dominant bird species of man-made marsh and Passer montanus (0.41%) was the most dominant bird species of lake habitat. On the contrarily, Microhierax fringillarius and Turdoides earlei (each 0.01%) were the rarest species of man-made marsh and Dinopium javanense (0.02%) was the rarest species of the lake habitat. The bird relative abundance of man-made marsh and lake habitats was significantly different (F1,194 = 50.3, p<0.05). Community analysis indicated that bird species of man-made marsh were more diverse i.e., Shannon’s index (N1 = 3.92) and rich i.e., Margalef’s index (R1 = 8.93) than the lake habitat. Insectivore (marsh; 21.13% and lake area; 1.21%) was the most dominant guild in man-made marsh and lake area. In contrast, Piscivore (0.14%) was the rarest guild comprised of only one species in marsh habitat. The results of this study revealed that the man-made marsh was more capable to attract a higher number of bird species and diversity than the lake habitat.

Water Quality Parameters and Bird Diversity in Jagdishpur Reservoir, Nepal

Water quality parameters were analyzed seasonally to examine relationships with bird numbers and species richness in Jagdishpur reservoir. This wetland is a Ramsar site and an important bird area (IBA) of Nepal. The trophic status of the reservoir was categorized as eutrophic as assessed by Secchi disk transparency (1.45 ± 0.53 m), total alkalinity (220.94 ± 85.52 mg/l) and total nitrogen (884.19 ± 291.61 ?g/l) concentrations. Direct count method detected a total of 77 bird species belonging to 8 orders and 31 families of which 40 species were resident and 37 migrants. Species richness ranged from 21(summer) to 74 species (winter). Secchi disk transparency showed a significant positive correlation with bird numbers ((r = 1.00, p &lt; 0.01) whereas significant negative correlation was found between water temperature and species richness (r = - 0.97, p &lt; 0.05). Absolute positive correlation between species richness and seasons was established (r = 0.74). The seasonal distribution pattern showed two peaks of species richness, Shannon diversity, equitability and evenness index, one in winter and the other in autumn. Fulica atra (30.53%), Dendrocygna javanica (15.88%) and Anas strepera (9.58%) were the three most dominant bird species. Fourteen CITES species, 8 globally and 14 nationally threatened species were recorded. Conservation action plan for threatened species that focuses on population monitoring, protecting key habitats and habitat enhancement is urgently needed. Nepal Journal of Science and Technology Vol. 13, No. 1 (2012) 143-155 DOI: http://dx.doi.org/10.3126/njst.v13i1.7453

Avifauna of Bangtaesan Mountain, Gangwon-do, Korea

An investigation on avifauna of the Bangtaesan Mountain was carried out from February until November, 2010 and it drew the results as follow. The number of birds observed in the whole Bangtaesan Mountain region was 989 individuals of 51 species (Maximum counts). Considering the results from literature research in addition, at least 90 species 1,000 individuals are thought to live in this region. In result, dominant species proved to be Yellow-throated Bunting (Emberiza elegans), Marsh Tit (Parus palustris), Azure-winged Magpie (Cyanopica cyana), Eastern Crowned Willow Warbler (Phylloscopus coronatus), Varied Tit (Parus varius), and more. Most of birds breeding in the forest of Korea were found to constitute these dominant bird species. Entire species diversity index appeared to be 3.35 relatively a high level; 3.34 in the south slopes while 3.22 in the north slopes showing relatively a high level in the south. Of them, 12 species including Mandarin Duck (Aixgalericulata) were the Protected Birds species nominated and protected by the Cultural Heritage Administration or the Ministry of Environment, while 10 and 6 species were the natural monument species and endangered species level, respectively. Should further consistent surveys be carried out, a broader range of species would be found to breed, and therefore the Bangtaesan Mountain region including the area where the protected species are observed is believed to need a conservation and management through protected area designation.

Effects of exotic Spartina alterniflora on the habitat patch associations of breeding saltmarsh birds at Chongming Dongtan in the Yangtze River estuary, China

Smooth cordgrass (Spartina alterniflora) is one of the most invasive exotic plants of saltmarshes worldwide. To understand the effects of smooth cordgrass invasion on the habitat use and selection by breeding saltmarsh birds, we compared species number and abundance of breeding birds in native reed (Phragmites australis) and smooth cordgrass-invaded habitats (reed-cordgrass mixed habitats and cordgrass monocultures) at Chongming Dongtan in the Yangtze River estuary, China. We further examined the similarity of bird communities in different habitats and habitat selection by dominant bird species. For saltmarsh generalists, species number and abundance did not differ among the habitats. For saltmarsh specialists, species number and abundance did not differ in reed monocultures and reed-cordgrass mixed habitats but were significantly lower in cordgrass monocultures than in reed monocultures and reed-cordgrass mixed habitats. ANOSIM indicated that the difference in bird communities was larger between cordgrass monocultures and the habitats with reed than between the habitats with reed. The saltmarsh specialists preferred reed monocultures, while saltmarsh generalists avoided reed monocultures. Most species indicated no selection (neither preferred nor avoided) on reed-cordgrass mixed habitats, and no species preferred the cordgrass monocultures. The use of cordgrass monocultures by the common saltmarsh birds was negatively related to their body size. This study suggests that the spread of exotic smooth cordgrass has greatly affected the species composition and structure of local bird communities and has been especially disadvantageous to the saltmarsh specialists.

Composition and characteristics of understory bird communities in monsoon evergreen broadleaved forest of Mengyang, Xishuangbanna in the dry season

Understory birds in monsoon evergreen broadleaved forest of Mengyang, Xishuangbanna, Yunnan were sampled using mist nets from October 2008 to March 2009. A total of 1423 individuals of 90 species belonging to 28 families and 7 orders were captured, among which there are 8 dominant bird species, i.e., Sliver-breasted Broadbill (Serilophus lunatus), Brown-cheeked Fulvatta (Alcippe poioicephala), White-throated Bulbul (Alophoixus pallidus), Golden-spectacled Warbler (Seicercus burkii), White-tailed Robin (Cinclidium leucurum), Black-breasted Thrush (Turdus dissimilis), Streak-Breasted Jungle Babbler (Pellorneum ruficeps), and Buff-breasted Jungle Babbler (Trichastoma tickelli). Resident birds, the major composition of the understory birds, accounted for 89.3 percent of total captures. The mean capture rate was 9.0+-3.7 individuals/(100 net-hours) and it differed significantly between months, highest in December 2008 (12.5+-1.3)individuals/(100 net-hours), lowest in February 2009 (5.2+-0.6) individuals/(100 net-hours). The most significant characteristic of understory birds in Xishuangbanna is more species abundance and lower species density compared to understory bird composition of South China. Another characteristic is that no obvious dominance pattern was observed in Babbler species. We also noticed that silver-breasted Broadbill, National Key Protection Bird, is the most abundance species in our captures, thus their habitat require further protection.

Temporal changes to spatially stratified waterbird communities of the Coorong, South Australia: implications for the management of heterogenous wetlands

AbstractThe Coorong, South Australia, is a globally significant wetland system, listed in the Ramsar Convention under a number of different criteria, including its importance to waterbird populations. Based on annual waterbird censuses conducted between 2000 and 2007, spatiotemporal analyses revealed that significant differences in waterbird community structure exist along the length of the Coorong. This spatial diversity in community structure was also found to be temporally consistent over this 8‐year period. The abundance of the most numerically dominant bird species, such as red‐necked stint Calidris ruficollis and grey teal Anas gracilis, explained much of this spatial variation. However, comparisons between data collected for the Coorong south lagoon in 1985 and 2000–2007 show that dramatic changes in these waterbird communities have occurred over longer periods of time, with 23 of the 27 most common species having declined in this period by at least 30%. The Coorong still regularly supports globally important populations (&gt;1% of global population) of nine waterbird taxa, including three Palearctic shorebirds, confirming its Ramsar status. The functional links between the overutilized Murray‐Darling basin river system and the Coorong are discussed.

Spectral Overlap in Songs and Temporal Avoidance in a Peruvian Bird Assemblage

AbstractAcoustic signals are very important in communication among conspecifics for many animals, especially in relatively dark, densely foliated habitat such as tropical rainforest. However, as many species all have to use the same acoustic space, this may lead to interference and masking. Songs will function efficiently in attracting mates or defending territories depending on the level of spectral and temporal overlap with songs of other species in the local community. As signal efficiency has direct fitness consequences, organisms may have evolved a strategy to avoid competition for acoustic space. We hypothesize that, as a consequence, species in a complex rainforest community may show spectral segregation or temporal avoidance: singing at a different frequency or at a different time. As doing both is superfluous and acoustic space is limited, we expect a negative correlation between spectral and temporal overlap. We tested this hypothesis in recordings of 20 vocally dominant bird species from 14 families in a Peruvian rainforest. Using pair‐wise comparisons between bird species, we found one significant correlation between spectral overlap and temporal overlap. All others were non‐significant. However, we did find that, at frequencies more often used by multiple bird species, there was significantly less overlap than expected if all species were just singing randomly ignorant of each other’s songs. Our analyses indicate that short‐term auditory feedback mechanisms may also operate in the biodiverse environments of the tropics and may explain part of the community dynamics of acoustic signalling in the rainforest.

Relationships between vegetation and bird community composition in grasslands of the Serengeti

AbstractThe Serengeti–Mara ecosystem holds one of the largest natural grasslands of the world, which is well known for its large herds of mammals. However, the bird community structure of these grasslands has hardly ever been studied. For the first time, a large‐scale study on grassland bird communities has been conducted in all typical open grasslands of the Serengeti National Park. We used ten grassland plots representing a gradient of increasing vegetation height and also including shrubs and trees to analyse the influence of vegetation structure on the composition of grassland bird communities. Three communities of breeding birds were identified in relation to (a) short grass, (b) intermediate and long grass and (c) wooded grasslands. The bird communities of intermediate, long and wooded grassland were very similar, because of identical dominant bird species. Our results suggest that breeding birds of East African grasslands exhibit two contrasting habitat relationships: (1) birds that are restricted to short grass, and (2) species that are tolerant to vegetational shifts from intermediate grass via long grass to early stages of woody vegetation. Because the vegetation is often driven beyond this range in managed tropical grasslands through high grazing pressure or through shrub encroachment, we expect that the long‐grass bird communities will not generally resist anthropogenic disturbance.

Avifauna in grassland communities at some inland airports in South Africa.

Over a period of eleven years (January 1985 – December 1995) approximately 5 000 individuals representing 51 bird species which, potentially, posed a threat to aviation were collected at the Bloemfontein airport. More than half of the species concerned can be considered as medium sized terrestrial birds of which the crowned plover (Vanellus coronatus) is by far the most important. A similar species composition occurred at the Kimberley airport, in contrast to the greater percentage of water associated birds at the Johannesburg airport. Indirectly, food availability appears to be one of the main environmental factors involved in the presence of the five dominant bird species at the Bloemfontein airport.

Biogeographical comparison of winter bird assemblages in urban environments in Finland

We studied biogeographical variation of urban bird assemblages in Finland. Winter birds were censused by single‐visit study plot method from thirty‐one centres of villages or towns along 950 km latitudinal extent. A total twenty‐eight bird species was observed and the average density was 61.2 ind./10 ha. The number of dominant species in study areas varied between two and seven and their proportion of the whole assemblage was over 70%. Species richness, but not the density of birds, decreased northwards in pooled data. Higher species richness in south than in north was mainly due to the higher amount of delayed migratory birds (e.g. waterbirds, finches) and southerly distributed bird species. However, in heavily urbanized areas species richness did not decrease northwards. This observation disagreed with the hypothesis that species richness decreased northwards. Bird density, but not species richness, increased with urbanization. In particular, feral pigeon, hooded crow and house sparrow had highest densities in most urbanized areas. As only few bird species are adapted to live in urban areas, species composition and dominant bird species were almost the same in the south and in the north. These urban birds may effectively use energy rich food in feeding tables and overcome the problems of severe climate in the north. This may be the reason why bird species richness does not decrease northwards in urban areas.

Fronts and Seabird Aggregations in the Southeastern Bering Sea

Fronts and Seabird Aggregations in the Southeastern Bering Sea

Pattern and Process in Grassland Bird Communities

Variations in abundance and distribution of bird species and avifaunal and community organization at regional, local, and within—plot levels were studied during 1969 and 1970 at a shortgrass prairie in Colorado and during 1970 at six additional International Biological Program (IBP) grassland sites. Patterns were generally not distinct at the regional level, although low rainfall sites tended to support fewer individuals and less biomass than more mesic sites. The dominant bird species were widely distributed, but 70% of all species recorded were present at only one of the seven sites. Local plot—to—plot differences, associated with grazing intensity, were considerably more important than the regional differences. Vegetational and avifaunal relationships of plots were determined by similarity—cluster analysis and by examination of vegetation structure. Variations in the number of breeding bird species, bird—species diversity, or equitability, were unrelated to the gradient of plots from tallgrass through shortgrass to desert, but standing crop biomass generally decreased along this gradient. The plots differed in the proportions of small, medium, and large—sized species. Shortgrass sites were generally dominated by omnivorous species; plots with a greater vegetation structure supported more carnivorous forms. Only carnivorous species occurred at the desert site. The effect of grazing on bird populations varied among the treatment plots at the various sites. In the Colorado shortgrass prairie, grazing season had a greater effect on community organization than grazing intensity. Patterns of variation were much more pronounced when single species rather than breeding faunas were considered. Grasshoppers, Lepidoptera larvae, beetles (especially curculionids, carabids, cerambycids, and scarabaeids), ants, and various seeds were the most important prey of the dominant bird species. Small sparrows and larks had generally similar diets. The diets of the larger meadowlarks and shorebirds differed from those of the former group and also differed from each other. The proportion of seeds and arthropods in the diets of Lark Buntings and Horned Larks varied considerably with time. Diurnal raptors, studied at only one site, were widely dispersed, occurring at densities and standing crops substantially less than those of small passerine populations. Owls preyed chiefly upon small mammals and insects, but the proportions of these food items in the diet differed significantly among the four species studied. The estimated energy intake of the breeding bird populations from April through August ranged from 1.01 to 2.33 kcal/m2; thus the energy flux through avian consumers in grasslands is apparently very small. In general, seeds decreased in importance as energy sources and arthropods increased in importance along a gradient from shortgrass through mixed grass to tallgrass plots. Secondary production estimated for six grazing—treatment plots ranged from 3.9 to 6.9 x 10—3 g/m2. The role of birds as consumers in the dynamics of grassland ecosystems is considered. It is suggested that birds may act as controllers of other elements of system function or may not be closely evolved into the functional framework of the ecosystem at all, existing on "excesses" in production.