Summer and winter bird populations associated with five age-classes of aspen forest in Alberta

1993 ◽  
Vol 23 (9) ◽  
pp. 1830-1836 ◽  
Author(s):  
D. A. Westworth ◽  
E. S. Telfer
Keyword(s):  
Habitat Structure ◽  
Bird Species ◽  
Canopy Cover ◽  
Species Number ◽  
Age Classes ◽  
Bird Populations ◽  
Clear Cut ◽  
Number Of Species ◽  
Bird Density ◽  
Large Trees

Summer and winter bird use of aspen forests was studied in west central Alberta. Forest age-classes in the study included 1- and 2-year-old clear-cut areas and.14-, 30-, 60-, and 80-year-old stands. Habitat structure and composition were quantified by a combination of measurement and estimation of variables. Density of the breeding bird population was estimated by territorial mapping. Changes in habitat structure between different age-classes resulted in a successional replacement of bird species. Number of individuals was greatest in 14-year-old stands at 656 territories per 100 ha, probably owing to the presence of remnant snags and of large trees that had survived past fires. The 30-year-old stands supported 312 territories per 100 ha, 60-year-old stands 380 territories, and 80-year-old stands 231 territories, respectively. Recently clear-cut areas supported only 110 territories. Number of species followed the same pattern with 25 in 14-year-old stands, 22 in the 30-year-old stands, 21 in the 60-year-old stands, and 14 in the 80-year-old stands. Recent clearcuts supported 10 species. In winter 13 bird species were recorded in the combined clear-cut, 14-, 30-, and 60-year-old stands. The highest number of species (11) were recorded in the 60-year-old stand during winter but the greatest winter bird density (125 individuals/100 ha) occurred in the 30-year-old stand. Three principal components extracted from the habitat data explained 83.2% of the variance in bird use. The components corresponded to gradients in canopy cover, occurrence of conifers, and shrub density.

scholarly journals Impacts of deforestation on passerine avifauna in the Opunohu Valley of Mo'orea, French Polynesia

2016 ◽  
Author(s):  
Vanessa M. ZoBell ◽  
Brett J Furnas
Keyword(s):  
Detection Probability ◽  
Bird Species ◽  
Canopy Cover ◽  
French Polynesia ◽  
Passerine Bird ◽  
Oceanic Islands ◽  
Bird Populations ◽  
Green Fruit ◽  
Discrete Nature ◽  
Acoustic Recording

Human expansion has negatively impacted biodiversity. Oceanic islands have some of the most diverse, endemic biodiversity. Endemism leads to vulnerability due to the isolated and discrete nature of oceanic islands. Birds are indicator species that adapt to change very quickly. By analyzing birds, we can investigate how changes in behavior and abundance may occur for different species in the future. Nine passerine bird species were studied with automated acoustic recording devices. Recording devices were places in agricultural, forest, and mixed habitats. Three invasive species preferred agriculture areas and low canopy cover, based on call frequency and detection probability. Native bird detectability was significantly lower than invasive bird detectability. Occupancy was above 0.8 for all species, except for the gray-green fruit dove that was >0.6. Native bird populations are at risk, based on their calling number and detection probability.

scholarly journals Respon Komunitas Burung terhadap Pembangkit Listrik Tenaga Panas Bumi (PLTP) Kamojang, Bandung, Jawa Barat

2018 ◽  
Vol 12 (2) ◽  
pp. 156 ◽  
Author(s):  
Diyah Kartikasari ◽  
Satyawan Pudyatmoko ◽  
Novianto Bambang Wawandono ◽  
Pri Utami
Keyword(s):  
Power Plant ◽  
Bird Species ◽  
Bird Community ◽  
Bird Communities ◽  
Bird Diversity ◽  
Species Number ◽  
Point Count ◽  
Geothermal Power Plant ◽  
Number Of Species ◽  
Geothermal Power

Penelitian ini bertujuan untuk mengetahui respon komunitas burung terhadap keberadaan Pembangkit Listrik Tenaga Panas Bumi Kamojang. Kami membandingkan keanekaragaman dan kekayaan jenis burung pada lokasi yang terdampak (DL) dan tidak terdampak (TL) di Wilayah Kerja Panas Bumi Kamojang, Cagar Alam Kamojang dan Taman Wisata Alam Kamojang di Kabupaten Bandung Provinsi Jawa Barat. Lokasi yang terdampak berada di sekitar sumur produksi atau pembangkit listrik tenaga panas bumi (30 sampel) sedangkan lokasi yang tidak terdampak adalah dengan jarak 3.000 m sampai 9.000 m dari fasilitas tersebut (42 sampel). Pengumpulan data dilakukan selama dua musim; musim kemarau dan penghujan (2015-2016). Kami mengumpulkan data komunitas burung dan data habitat dengan metode point count yang ditempatkan secara sistematis di setiap lokasi. Kami menemukan 124 spesies burung yang terdiri dari 35 famili dan 16 spesies di antaranya adalah burung endemik di Pulau Jawa. Dua puluh tiga spesies dilindungi oleh undang-undang di Indonesia, sembilan spesies termasuk dalam daftar lampiran CITES dan lima spesies masuk dalam Daftar Merah Spesies Terancam IUCN tahun 2017. Terdapat perbedaan respon antara komunitas burung di lokasi terdampak dan tidak terdampak yang ditunjukkan dengan perbedaan rata-rata jumlah spesies, jumlah individu masing-masing spesies, indeks keanekaragaman ShannonWiener. Lokasi tidak terdampak memiliki nilai lebih tinggi pada parameter ini dibanding lokasi yang terkena dampak. Demikian juga, jumlah spesies, jumlah individu vegetasi dan indeks keanekaragaman hayati ShannonWiener pada lokasi TL memiliki nilai rata-rata lebih tinggi daripada lokasi DL. Hal ini membuktikan bahwa meskipun panas bumi dianggap sebagai energi ramah lingkungan namun dalam penggunaannya masih berdampak pada keanekaragaman hayati di sekitarnya terutama untuk jenis burung. Response of Bird Community to Kamojang Geothermal Power Plant, Bandung, West JavaAbstractThis study aimed to investigate the response of bird communities on the presence of geothermal power plant of Kamojang. We compared the bird diversity and richness of affected (DL) and not affected (TL) in Kamojang Geothermal Working Area, Kamojang Nature Reserve and Kamojang Nature Park in Bandung regency of West Java Province. The affected sites were surrounding production wells or geothermal power plants (30 samples) whereas not affected sites were with distance of 3,000 m to 9,000 m from those facilities (42 samples). The data collection was carried out during two seasons; dry and rainy season in (2015-2016). In each site, we collected bird community data and habitat data with the point count method which was placed systematically on each sites. We found 124 birds species belongs to 35 families with 16 endemic species in Java Island. Twenty three species are protected by Indonesian law, with nine species are in the CITES appendix list and five species are listed in the IUCN Red List of Threatened Species of 2017. There was a difference of responses between bird communities in the affected and not affected sites which is indicated by differences in the mean number of species, number of individuals in each species, and Shannon-Wiener's diversity index. The not affected sites had higher value on these parameters than the affected sites. Similarly, number of species, number of individual vegetation, and Shannon-Wiener biodiversity index in TL sites had higher mean values than DL sites. This proves that although geothermal is considered as environmentally friendly energy but in its utilization it still has an impact on the surrounding biodiversity especially for bird species.

scholarly journals Impacts of deforestation on passerine avifauna in the Opunohu Valley of Mo'orea, French Polynesia

2016 ◽  
Author(s):  
Vanessa M. ZoBell ◽  
Brett J Furnas
Keyword(s):  
Detection Probability ◽  
Bird Species ◽  
Canopy Cover ◽  
French Polynesia ◽  
Passerine Bird ◽  
Oceanic Islands ◽  
Bird Populations ◽  
Green Fruit ◽  
Discrete Nature ◽  
Acoustic Recording

Human expansion has negatively impacted biodiversity. Oceanic islands have some of the most diverse, endemic biodiversity. Endemism leads to vulnerability due to the isolated and discrete nature of oceanic islands. Birds are indicator species that adapt to change very quickly. By analyzing birds, we can investigate how changes in behavior and abundance may occur for different species in the future. Nine passerine bird species were studied with automated acoustic recording devices. Recording devices were places in agricultural, forest, and mixed habitats. Three invasive species preferred agriculture areas and low canopy cover, based on call frequency and detection probability. Native bird detectability was significantly lower than invasive bird detectability. Occupancy was above 0.8 for all species, except for the gray-green fruit dove that was >0.6. Native bird populations are at risk, based on their calling number and detection probability.

scholarly journals Habitat structure and diversity influence the nesting success of an endangered large cavity-nesting bird, the Southern Ground-hornbill

Koedoe ◽  
2017 ◽  
Vol 59 (1) ◽  
Author(s):  
Leigh Combrink ◽  
Hendrik J. Combrink ◽  
André J. Botha ◽  
Colleen T. Downs
Keyword(s):  
Habitat Structure ◽  
Bird Species ◽  
Nesting Success ◽  
Bush Encroachment ◽  
Data Set ◽  
Large Herbivores ◽  
Term Survival ◽  
Nest Sites ◽  
Large Trees

Habitat features can have a profound effect on the nesting success of birds. Savannas are often managed with predators and large herbivores as priority species, with little thought to the many bird species that management decisions could affect. Using a data set spanning seven breeding seasons, we examined how nesting success of Southern Ground-hornbills (SGHs) Bucorvus leadbeateri in the Kruger National Park varied as a result of various environmental and habitat factors within a radius of 3 km surrounding the nest site. Identifying which factors affect nesting success will allow for targeted management efforts to ensure the long-term survival of SGHs both within and outside of protected areas. Habitat structure and diversity of the vegetation surrounding the nest were the most influential factors on SGH nesting success. SGHs require open grassy areas for foraging and areas with large trees for nesting. Savanna habitat drivers such as elephants and fire should be managed to ensure that sufficient large trees are able to establish in the landscape and to control for bush encroachment. This is especially important in areas earmarked for SGH reintroductions. Nest sites of SGHs should be monitored to mitigate any structural changes in the habitat surrounding the nests. Nests should be modified or artificial nest sites provided, where nests have been damaged or lost, to ensure the continued presence of these birds in African savannas.Conservation implications: Habitat structure and diversity surrounding Southern Groundhornbill nests has a significant impact on their nesting success. This highlights the importance of monitoring vegetation change in savanna habitats where they occur. Management of savanna areas should take factors that influence bush encroachment, such as fire and elephants, into account to ensure the long-term persistence of these birds.

Variations in pest bird density in Argentinean agroecosystems in relation to land use and/or cover, vegetation productivity and climate

2018 ◽  
Vol 45 (8) ◽  
pp. 668 ◽  
Author(s):  
Noelia C. Calamari ◽  
Sonia B. Canavelli ◽  
Alexis Cerezo ◽  
Sebastián Dardanelli ◽  
Jaime N. Bernardos ◽  
...  
Keyword(s):  
Land Use ◽  
Population Distribution ◽  
Bird Species ◽  
Crop Damage ◽  
Vegetation Productivity ◽  
Monk Parakeet ◽  
Bird Populations ◽  
Myiopsitta Monachus ◽  
Bird Density

Context Changes in environmental conditions may influence bird populations, including pest bird species, and their distribution. In Argentina, particularly in the Pampas region, agricultural expansion has resulted in important changes in agroecosystems, with impacts on bird species. Aims This study analysed the relationship between pest bird densities and the environmental variables associated with land use and/or cover, vegetation productivity and climate. The study focused on the most important pest bird species to grain crops in Argentina and Uruguay: the eared dove (Zenaida auriculata) and the monk parakeet (Myiopsitta monachus). Methods An area in Central Argentina was divided into three agro-productive regions, one predominantly agricultural and two with mixed production activities: agricultural rangeland and agricultural forested rangeland. Bird populations were sampled on a yearly basis between 2003 and 2011 in point-transects located along secondary roads (47 routes in total). Linear mixed models and a multi-model inference approach were used to compare the effects of individual predictive variables on bird densities. Key results Mean estimated density for the eared dove was 0.39 individuals per ha (±0.02), almost three times the density of the monk parakeet (0.10 individuals per ha±0.02). The spatial distribution of changes in density of the eared dove and monk parakeet showed irregular patterns across the study area. Density of eared dove was directly related to cover of native and exotic woodlots and inversely related to cover of fallow and weedy fields, and to temperature and rainfall. Monk parakeet density, in turn, was directly related to cover of woodlots. Conclusions The density of eared doves and monk parakeets changed mostly in relation to land use and/or cover and, to a lesser extent, to climatic conditions. Information of pest bird populations in a long-term period allowed us to understand spatial patterns in bird population distribution and to identify the main environmental factors explaining them. Implications The consideration of land use and/or cover, vegetation productivity and climate variables at regional scale, measured during a long-term period, would be critical for anticipating population increases and, possibly, increases in crop damage.

scholarly journals The Mid-Winter Assemblage And Diversity Of Bird Populations At Patlakhawa Protected Forest, Coochbehar, West Bengal, India

Ring ◽  
2014 ◽  
Vol 35 (1) ◽  
pp. 31-53 ◽  
Author(s):  
Asitava Chatterjee ◽  
Shuvadip Adhikari ◽  
Anandamay Barik ◽  
Subhra Kumar Mukhopadhyay
Keyword(s):  
West Bengal ◽  
Bird Species ◽  
Diversity Indices ◽  
Point Of View ◽  
Species Number ◽  
Habitat Types ◽  
Swamp Forest ◽  
Bird Populations ◽  
Niche Diversity ◽  
Habitat Fidelity

ABSTRACT We compared avian community structure of six contrasting habitat types at Patlakhawa Protected Forest of Dooars of West Bengal. During three weeks of the mid-winter studies 154 bird species representing 41 families were recorded. Of the 154 recorded species, 22 were observed in grasslands, 22 in swamp forest, 46 in riverine forest, 52 at miscellaneous plantation areas, 43 at forest edges and 51 at wetlands. The Shannon-Wiener general diversity indices varied among the habitats and ranged from 2.323 to 3.458. Richness (5.813-11.410), evenness (0.406-0.641) and dominance (0.042-0.128) indices also varied considerably among the study locations. The highest diversity, the lowest dominance and a very high evenness were characteristics of miscellaneous plantations. Grasslands showed highest evenness and considerably high species diversity. The lowest avian evenness and diversity were recorded in wetlands and swamp forests. Insectivorous birds were most numerous (53), followed by carnivorous (40), omnivorous (29) and frugivorous (15) birds. Winter appeared to be the best time for niche occupancy at the Himalayan foothills for assemblages of either winter migrants and visitors or altitudinal and passage migrants, as about 30% of all encountered species were migrants. 96 bird species were observed to occur at any one of these habitat types showing high habitat fidelity. Mixed avian foraging assemblages that varied in species number and compositions were observed and they contain 11 to 17 species. Avifaunal niche diversity and richness in different habitats of Patlakhawa Protected Forest during mid-winter envisaged its importance from conservation point of view.

scholarly journals Changes in surface water drive the movements of Shoebills

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marta Acácio ◽  
Ralf H. E. Mullers ◽  
Aldina M. A. Franco ◽  
Frank J. Willems ◽  
Arjun Amar
Keyword(s):  
Surface Water ◽  
Optimal Foraging ◽  
Animal Movement ◽  
Bird Species ◽  
Individual Variability ◽  
Home Ranges ◽  
Age Classes ◽  
Water Index ◽  
Normalized Difference Water Index ◽  
Conservation Actions

AbstractAnimal movement is mainly determined by spatial and temporal changes in resource availability. For wetland specialists, the seasonal availability of surface water may be a major determinant of their movement patterns. This study is the first to examine the movements of Shoebills (Balaeniceps rex), an iconic and vulnerable bird species. Using GPS transmitters deployed on six immature and one adult Shoebills over a 5-year period, during which four immatures matured into adults, we analyse their home ranges and distances moved in the Bangweulu Wetlands, Zambia. We relate their movements at the start of the rainy season (October to December) to changes in Normalized Difference Water Index (NDWI), a proxy for surface water. We show that Shoebills stay in the Bangweulu Wetlands all year round, moving less than 3 km per day on 81% of days. However, average annual home ranges were large, with high individual variability, but were similar between age classes. Immature and adult Shoebills responded differently to changes in surface water; sites that adults abandoned became drier, while sites abandoned by immatures became wetter. However, there were no differences in NDWI of areas used by Shoebills before abandonment and newly selected sites, suggesting that Shoebills select areas with similar surface water. We hypothesise that the different responses to changes in surface water by immature and adult Shoebills are related to age-specific optimal foraging conditions and fishing techniques. Our study highlights the need to understand the movements of Shoebills throughout their life cycle to design successful conservation actions for this emblematic, yet poorly known, species.

Temporal patterns in the macrobenthic communities of the Hawkesbury estuary, New South Wales

1987 ◽  
Vol 38 (5) ◽  
pp. 607
Author(s):  
AR Jones
Keyword(s):  
Community Composition ◽  
Temporal Patterns ◽  
Single Species ◽  
Species Number ◽  
Community Patterns ◽  
Low Salinity ◽  
Number Of Species ◽  
South Wales ◽  
Physicochemical Factors ◽  
Number Of Individuals

Temporal patterns in number of species, number of individual animals and community composition of the soft-sediment zoobenthos of the Hawkesbury estuary are described and related to physicochemical factors. Replicate grabs were taken at 3-month intervals over 3 years (1977-1979) from sites located in three zones: the lower, middle and upper reaches. The number of species and number of individuals showed significant seasonal and annual differences in all zones. However, the pattern of these differences varied among sites and seasonal differences were not repeatable over years. Similarly, differences in community composition as revealed by classification were not seasonal. In the middle and lower reaches, these differences were apparently caused by the over- riding influence of non-seasonal climatic events, i.e. a major flood in 1978 and a drought throughout 1979. In the first two sampling following the flood, sample values for the numbers of both species and individuals were usually lowest and community composition was distinct from pre-flood and drought times. During the drought, the number of species was usually high and community composition relatively distinct. Whereas the number of species and community composition groupings were both significantly related to river discharge, the number of individuals was significantly correlated with temperature. All community variables were sometimes significantly related to salinity. The identity of numerically dominant species, as determined by Fager rankings, varied among times in both the lower and middle reaches. However, the polychaete Nephtys australiensis and the bivalve mollusc Notospisula trigonella were highest ranked overall in both zones. Community patterns in the low-salinity upper reaches differed from those further downstream by showing little change in numbers of species and community composition following the flood. Only the number of species was significantly correlated with any of the measured physicochemical variables, this being partly due to an influx of species during the drought. Furthermore, the upstream community was always dominated by the polychaete Ceratonereis limnetica and was thus the only community that could be characterised by a single species.

scholarly journals The Occurence of Ecological Traps in Bird Populations: Is our Knowledge Sufficient? A Review

2012 ◽  
Vol 5 (3) ◽  
pp. 36-56 ◽  
Author(s):  
Petr Suvorov ◽  
Jana Svobodová
Keyword(s):  
Exotic Species ◽  
Species Conservation ◽  
Habitat Type ◽  
Bird Species ◽  
Ecological Trap ◽  
Native Communities ◽  
Bird Populations ◽  
Suburban Areas ◽  
Arable Fields ◽  
Insufficient Time

ABSTRACT Anthropogenic changes in a landscape create new cues for birds, which must permanently adapt to these. If landscape changes occur too quickly, individuals have insufficient time to develop adequate reactions. They may, therefore, preferentially nest in low-quality habitats, which can lead to diminished nesting success and to reduction of their population size. This is usually termed the ecological trap hypothesis. We reviewed 38 studies investigating this phenomenon and analysed whether relationships exist between ecological trap occurrence and geographical region, habitat type, and/or life strategies of bird species. Ecological traps were most often associated with the presence of exotic species. Exotic species can modify environmental conditions in ways to which native communities are not adapted. They have been mainly detected in open habitats. Such open habitats as arable fields and meadows are under greater human pressure, and rapid changes probably occur there more frequently. Although more studies from North America were investigated, the hypothesis was supported more frequently in European studies. This is possibly due to higher human population density and, hence, more frequent habitat changes. Our results show that an ecological trap is not likely associated with migration. Ground nests suffered fewer consequences of such traps than did other nest types. Although the implications of the ecological trap hypothesis in species conservation are undisputable, a more detailed approach is still needed. For instance, some habitat types, such as suburban areas, have been neglected in the context of ecological traps, as has been the phenomenon’s appearance in pristine habitats.

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