Habitat Preferences Of Birds Research Articles

A statistical approach on distribution and seasonal habitat use of waterfowl and shorebirds in Çıldır Lake (Ardahan, Türkiye).

Wetlands are crucial habitats for both migrant and resident bird assemblages. The distribution and habitat preferences of birds in aquatic ecosystems are significantly influenced by environmental and ecological factors that critically impact the relevant habitats. In order to reveal the distribution and habitat preferences of the birds, many statistical models and methodologies are employed in ecology and conservation biology. Herein, we investigated the effects of year, season, habitat, and species variables on the distribution and population dynamics of waterfowls and shorebirds associated with the wetland. In this regard, field surveys were carried out in and around Çıldır Lake (Ardahan, Türkiye) between April 2017 and September 2018 to examine the distribution of waterfowls and shorebirds and variations in population sizes. As an experimental design, a stratified random sampling design was used to assess bird fauna in the four dominant habitat types (open water surface, reeds, grasslands, and agricultural areas) in the study area. Accordingly, a total of 51 waterfowl and shorebird species were identified during the study period. Of the identified families, Anatidae (n = 18), Scolopacidae (n = 8), and Ardeidae (n = 8) were the most common families. Considering bird species, common coot Fulica atra and mallard Anas platyrhynchos were the most abundant species. The dependent variable (bird populations) was compared with the independent variables (year, season, habitat, and species). The population in 2018 decreased by 13% in comparison to the population in 2017 (p < 0.05). Once the reed area was considered as the reference, the population density in the water surface habitat increased by 65% (p < 0.001). In relation to seasonal reference, a 65% increase in population growth in spring was recorded in comparison to the growth in fall (p < 0.001). On the other hand, no statistical differences were noted in population growth in winter and summer ((p > 0.05). With respect to the reference species (Anas crecca), critical differences in species fluctuation were observed among species (p < 0.001). Consequently, the findings of the present study suggest that seasonal factor might be of the substantial factors linked to the habitat composition. However, more descriptive and predictive analytical methods are needed beyond classical regression approaches in habitat use and selection studies at bird ecology.

Habitat Preferences of Birds in Relation to Exotic Trees in Canal Bank Forests Gujranwala, Pakistan

Habitat Preferences of Birds in Relation to Exotic Trees in Canal Bank Forests Gujranwala, Pakistan

Landscape heterogeneity and management practices drive habitat preferences of wintering and breeding birds in intensively-managed fruit-tree plantations

Intensively-managed fruit-tree plantations consisting of low-stem trees have progressively replaced traditional high- and mid-stem orchards in Europe during the intensification of agriculture in the second part of the 20th century. Such perennial agricultural systems often form dense, homogeneous landscapes interspersed with open fields, urban areas and semi-natural structures. This observational study investigated the patterns driving landscape- and field-scale habitat preferences of bird communities in landscape units with varying fractions of intensively-managed fruit-tree plantations. At landscape scale, habitat homogeneity, notably a large proportion of fruit-tree plantations, had negative effects on both overall bird species richness and on the abundance of insectivorous birds. A higher proportion of semi-natural features, such as natural woody structures (hedgerows, isolated trees and forest patches) and marshes, positively affected overall bird species richness and abundance as well as insectivorous bird abundance. At field scale, we detected general, trait- and species-specific preferences for older trees during both winter and spring. In winter, leftover fruit is a crucial resource driving field selection by the avifauna. In spring, bird preferences for low and sparse ground vegetation were best explained by increased food accessibility for terrestrially foraging birds. Overall landscape heterogeneity as well as in situ management practices both matter to enhance bird habitat in fruit-tree plantations. Increasing the proportion of diverse semi-natural structures would promote wintering and breeding bird diversity and abundance. At field scale, conditions for birds can be improved by preserving older fruit-tree plantations and by maintaining patches of bare ground and short vegetation in the plantation inter-tree rows. However, given the current high-intensity management in most fruit-tree plantations in our study area, promoting natural features within the wider landscape matrix might represent a more cost-effective solution to enhance bird biodiversity in this agro-ecosystem.

Altitudinal shifts in forest birds in a Mediterranean mountain range: causes and conservation prospects

SummaryMediterranean mountains are biodiversity hotspots where northern species occur surrounded by drier and warmer lowlands. In this context, global warming is pushing these species to higher elevations. This paper assesses whether forest birds have experienced a shift upwards over the elevation gradient in the last 35 years in the Guadarrama Mountains (600–2,400 m asl; central Spain). Alternatively, the paper tests whether the reported shifts are related to changes in forest structure resulting from rural abandonment and/or forest management. To do this, sampling carried out from 1976 to 1980 along the elevation gradient was repeated in 2014–2015. In addition, the habitat preferences of birds were used to test if the elevation shifts were related to changes in forest structure. Results show that the mean range position of birds associated with tree cover shifted downwards, a trend supported by an increase in tree-dependent birds at mid-elevations. These trends suggest that an increase in tree cover has buffered the altitudinal shifts of forest birds predicted by climate warming. Results also suggest that proper forest management may improve the resilience of forest bird communities to the pervasive effects of climate warming.

Large-scale versus small-scale agriculture: Disentangling the relative effects of the farming system and semi-natural habitats on birds’ habitat preferences in the Ethiopian highlands

While the Western World is facing an inexorable decline of its farmland biodiversity following continuous intensification of production modes, agricultural landscapes in Africa are still largely dominated by small-scale subsistence farming operated by smallholders, mostly harbouring high biodiversity. However, as most African countries are confronted to an unprecedented population growth and a rapid economic development, efforts to intensify food production are widespread, with concomitant potentially negative effects on biodiversity. We conducted a study in a highly contrasted agricultural landscape of the Ethiopian highlands comprising two distinct farming systems: large-scale farming relying on modern, combine machinery and technology (e.g. enhanced crop varieties, application of herbicides, pesticides and synthetic fertilizers) vs small-scale traditional farming. Our objective was to disentangle the effects upon avian biodiversity of the operating farming system and the extent of semi-natural habitat features in the wider landscape. We performed a model selection approach to assess habitat selection by the overall bird community as well as the wintering, endemic and open habitat species, respectively. Our results show that habitat preferences of birds in the Ethiopian highlands were mainly driven by the amount of semi-natural habitats within the landscape, with varying effects depending on the farming system itself. While large-scale farming had overall more negative effects on birds, some typical open habitat species were mostly restricted to these wide-open landscapes. Our findings thereby suggest that both farming systems could coexist as long as semi-natural habitats are preserved and agricultural management maintained in its current practices. We emphasize the urgent need to conduct further studies integrating the socio-economic aspects in order to better predict future impacts of agricultural intensification processes on African farmland biodiversity.

Anthropogenic impact on the distribution of the birds in the tropical thorn forest, Punjab, Pakistan

The present research was conducted to assess the anthropogenic impacts on avian diversity around the river Chenab, Pakistan. The avian diversity was recorded on different landscapes along the river Chenab, that is, forest, agricultural, rural, and urban habitats. The data on diversity and distribution of various avian species were collected through linear count along with direct count methods viz. personal observations and sound records and indirect count methods viz. presences of carcasses and meeting with local communities. The habitat preferences of birds varied significantly. A decline in avian diversity was observed from forest habitat to urban landscapes. One year of bird surveys compiled a total of 150 species from all habitats along the river Chenab. Computed statistical data show that Shannon's index provides a quantitative report of diversity which was highest at forest habitat (4.261) followed by rural forest habitat (3.746), agri–rural habitat (3.746), agriculture habitat (3.623), WLH (2.723), urban vegetative habitat (3.215), and very least at urban nonvegetative habitat (2.247). It can be concluded from the present study that many of the avian species have specific habitats and also noted that corridors and connections among different landscapes are important for the conservation of avian diversity.

Species, Functional Groups, and Habitat Preferences of Birds in Five Agroforestry Classes in Tabasco, Mexico

We studied species, functional groups, and habitat preferences of birds in five classes of agroforestry systems: agroforests, animal agroforestry, linear agroforestry, sequential agroforestry, and crops under tree cover in Tabasco, Mexico. Sampling sites were >2 km from natural forest fragments. Observations were made at 38 sites using 30-min point and transect counts in the morning and afternoon in the rainy season, season of northern winds, and dry season from June 2008 to May 2009. We observed 3,551 birds, which were assigned to 102 species: 72 were resident and 30 were migratory species. Overall efficiency of sampling was 82.4% and varied from 68.7% in linear agroforestry to 81.5% in animal agroforestry. Total species richness varied from 43 in sequential agroforestry to 64 in animal agroforestry. Species richness and Shannon diversity indices revealed no differences among agroforestry classes. Bird communities in animal agroforestry, linear agroforestry, and sequential agroforestry had similar species compositions, as did agroforests and crops under tree cover. Birds in all agroforestry classes were mainly forest generalists, although specialists of open areas were common, particularly in animal and sequential agroforestry. Only one individual of a forest specialist species was observed during sampling. Migrant species were mostly forest generalists, but some open area specialists occurred in animal agroforestry. Resident birds were distributed over all foraging guilds in all agroforestry classes, whereas migrants were mainly foliage-gleaning insectivores. Foraging guilds had different relative abundances among agroforestry classes. Structural diversity of agroforestry classes did not seem to influence bird species richness. Forest specialist species were virtually absent in agroforestry classes, but the avifauna in agroforestry is diverse and valuable in itself.

The status and habitat preferences of birds associated with coastal forest and grassland in southern Tanzania

The status and habitat preferences of birds associated with coastal forest and grassland in southern Tanzania

Habitat preferences of birds in a montane forest mosaic in the Bamenda Highlands, Cameroon

Although the high species richness and endemism of birds in the Bamenda Highlands has attracted ornithological research for decades, most studies have been restricted to bird communities of continuous montane forests. Instead, we focused on a mosaic landscape with montane forest remnants, where the habitat preferences of birds remain unknown. We performed an assessment of habitat associations of birds in the Bamenda Highlands in the Cameroon Mountains. Using a point count census method, we detected 71 species within the study area. The most abundant species were the Northern Double-collared Sunbird Cynniris reichenowi, the Oriole Finch Linurgus olivaceus, the Common Stonechat Saxicola torquata, the Thick-billed Seed-eater Serinus burtoni, the Black-crowned Waxbill Estrilda nonnula, the Brown-backed Cisticola Cisticola chubbi and the Yellow-breasted Boubou Laniarius atroflavus. Canonical correspondence analysis revealed that the most important environmental gradient structuring the bird community follows the forest coverage. We found that both endemic and non-endemic montane species are more closely associated with montane forest remnants, compared to widespread species. Endemic species are most closely dependent on continuous forest cover. However, some montane species did not show any clear habitat associations and thus can be viewed as local habitat generalists. This study shows that many restricted-range species (including endangered endemics) are able to live in fragmented landscapes, which cover a substantial part of the Bamenda Highlands. Therefore, conservation programmes should focus their action plans on these landscapes.