scholarly journals Distribution and population densities of selected uncommon bird species in Zambezi riparian forest, NE Namibia

2019 ◽  
Vol 5 (4) ◽  
pp. 5-11
Author(s):  
Grzegorz Kopij
Keyword(s):  
Population Density ◽  
Riparian Forest ◽  
Bird Species ◽  
Mapping Method ◽  
Population Densities ◽  
Zambezi River

A territory mapping method has been employed in 2015 to assess the population density of 8 non-passerine and 10 passerine uncommon bird species breeding in a peri-urban riparian forest (280 ha) along Zambezi River (7 km long) near Katima Mulilo NE Namibia. The population densities (pairs per 100 ha) are estimated as follows: Trumpeter Hornbill: 1.4, Schalow’s Turaco: 2.9, Green-backer Heron: 1.1, Little Bittern: 0.4, Lesser Jacana: 0.4, African Finfoot: 0.4, White-crowned Lapwing: 0.7, Long-billed Crombec: 3.9, Yellow White-eye: 4.3, Scarlet-chested Sunbird: 0.7, African Golden Oriole: 2.9, Black-headed Oriole: 0.7, Violet-backed Starling: 0.7, Pied Wagtail: 8.6, Ashy Flycatcher: 0.4, Black Flycatcher: 0.4, Hartlaub’s Babbler: 4.3.

scholarly journals Diversity and population densities of coraciiform birds in Zambezi riparian forest

2019 ◽  
pp. 179-186
Author(s):  
Kopij G.
Keyword(s):  
Population Density ◽  
Surface Area ◽  
Riparian Forest ◽  
Mapping Method ◽  
Human Settlement ◽  
Population Densities ◽  
Forest C ◽  
Zambezi River

A territory mapping method was used in 2015 to assess the population density of coraciiform species breeding in a riparian forest on the Zambezi River near Katima Mulilo, NE Namibia. The forest, c. 280 ha in surface area, was partly transformed by human settlement and arable grounds. A total of 13 species and 42 breeding pairs were recorded. Population densities were (pairs/100 ha) as follows: grey–headed kingfisher 4.3; giant, pied and woodland kingfisher, each one with 1.1; malachite kingfisher 0.7; striped kingfisher 0.4; white–fronted bee–eater 1.4; little bee–eater 1.1; lilac–breasted roller 0.7; broad–billed roller 1.1; African hoopoe 0.7; red–billed wood–hoopoe 1.1; and scimitar–billed wood–hoopoe 0.4. Data published through GBIF (Doi: 10.15470/s9rlud).

scholarly journals Structure of the breeding bird community along the urban gradient in a town on the Zambezi River, north-eastern Namibia

Biologija ◽  
2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Grzegorz Kopij
Keyword(s):  
Riparian Forest ◽  
Bird Species ◽  
Similarity Index ◽  
Columba Livia ◽  
Urban Gradient ◽  
Feeding Guild ◽  
Breeding Bird ◽  
Urbanization Gradient ◽  
The Town ◽  
Zambezi River

A simplified mapping method was employed to quantify avian assemblages in three study plots in a modified riparian forest on the Zambezi River in the town of Katima Mulilo, NE Namibia. The plots were arranged along the urbanization gradient: plot A (34 ha; 0–1 km from centre of the town), plot B (27 ha; 1–2 km from the centre), and plot C (24 ha; 2–3 km from the centre; periphery). In total, 51 breeding bird species were recorded in all three plots. Five of them, Columba livia domestica, Passer diffusus, Pycnonotus tricolor, Streptopelia senegalensis, and Uraeginthus angolensis were classified as dominant species. The cumulative dominance was 69.9%. The overall population density of all breeding species increased with the urban gradient. In general, granivorous birds were by far the most numerous feeding guild comprising 68.7% of all breeding birds. Two other guilds, frugivorous and insectivorous birds, together comprised 28.9%. While the proportion of granivores decreased along the urban gradient from the town centre to its periphery, the proportion of insectivores increased. The proportion of birds nesting in/on buildings decreased, and the share of tree/shrub- and hole-nesting birds increased along the urban gradient. The diversity indices were relatively high in all plots. They decreased only slightly along the urban gradient (from the centre to the periphery). However, the Pielou’s Evenness Index was comparatively low, but on a slight increase along the urbanization gradient. The Sorensen Similarity Index was low, but the values of the three studied plots were very similar.

scholarly journals Birds of the Bloemfontein area, Free State Province, South Africa, during the years 1977-2000: an overview

2019 ◽  
Vol 62 (2) ◽  
pp. 41-76 ◽  
Author(s):  
Grzegorz Kopij
Keyword(s):  
South Africa ◽  
Bird Species ◽  
Common Species ◽  
Mapping Method ◽  
Breeding Birds ◽  
Free State ◽  
Line Transect ◽  
Bird Conservation ◽  
Population Densities ◽  
Distribution Maps

The aim of this paper is to summarize our knowledge of the birds of the Bloemfontein area, Free State, South Africa. It presents data on the status, distribution, population densities and habitat of the birds of this area, during the years 1977-2000 (with a special emphasis on the years 1993-1998). Both published and unpublished data are analysed. Population densities were estimated mainly using the line transect method and territory mapping method. For most fairly common, common and very common species, data on population densities are provided, while for 19 species (mainly rare or very rare), distribution maps of their occupied territories are presented. A total of 324 bird species were recorded. Breeding birds comprised 60.2% of the overall species (195), while non-breeding birds made up the remaining 39.8% (129). Among the breeding species, most (55.9%) were residents throughout the year, 3.1% were intra-African migrants and 1.2% were nomads. Non-breeding birds were represented by Palearctic migrants (35 species, 10.8%) classified as vagrants, irregular and regular visitors; and African non-breeding species (94; 29.0%), which were mainly vagrants. Among the breeding species, most were rare or very rare (100 species, 56.4%). Only 24 (12.3%) of them were very common, nine of which were non-passeres and 15 passeres. The main threat to birds in the Bloemfontein area is intensive agriculture. Some suggestions and recommendations are given for more effective and efficient bird conservation in this important area.

scholarly journals Population density and structure of birds breeding in an urban habitat dominated by large baobabs (Adansonia digitata), Northern Namibia

2019 ◽  
Vol 27 (4) ◽  
pp. 354-360
Author(s):  
G. Kopij
Keyword(s):  
Population Density ◽  
Nest Predation ◽  
Bird Species ◽  
Mapping Method ◽  
Urban Habitat ◽  
Adansonia Digitata ◽  
Feeding Guild ◽  
Avian Community ◽  
Breeding Bird ◽  
The Town

Large baobabs are regarded as key plant species in the savannah biome. In this study their role in shaping the avian community has been evaluated. The territory mapping method has been employed to quantify the avian breeding community in the town Outapi (ca. 130 ha), Northern Namibia, well-endowed with large baobabs. A total of 29 breeding bird species were recorded. The alien House Sparrow was by far the most numerous species comprising 48.4% of all breeding birds. The Blue Waxbill and African Palm Swift were also classified as dominant species, comprising together 17.4%. Granivores were by far the most numerous feeding guild, comprising 77.2% of all birds breeding, while the insectivores comprised only 11.8%. Birds nesting in/on buildings comprised 52.7%, those nesting on trees/shrubs – 42.0%. The population densities of many bird species (e.g. doves from the genus Stepropelia, bulbuls, weavers) were comparatively low. Such a situation could have been caused by the exceptionally high population density of the Pied Crow. In the study area, there were 15 breeding pairs and about 100–150 non-breeding individuals. The baobabs may provide them with a feeding resource in the form of the sweet fruits. The crows, as nest predators, feed also on the eggs and nestlings of other birds. Doves seem to be especially prone to such predation, as their nests are easily to detect and destroy. As a result, they have to breed in low density. This in turn, may release other dominant granivores in the study area, namely sparrows. They are not vulnerable to crow nest predation, as their nests are usually well-concealed under eaves and in holes of buildings.

scholarly journals Modelling the Impacts of Habitat Changes on the Population Density of Eurasian Skylark (Alauda arvensis) Based on Its Landscape Preferences

Land ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 306
Author(s):  
Nándor Csikós ◽  
Péter Szilassi
Keyword(s):  
Population Density ◽  
Land Cover ◽  
Arable Land ◽  
Bird Species ◽  
Landscape Patterns ◽  
Percentage Error ◽  
Alauda Arvensis ◽  
Rural Landscapes ◽  
Farmland Bird ◽  
Shape Complexity

The dramatic decline of the abundance of farmland bird species can be related to the level of land-use intensity or the land-cover heterogeneity of rural landscapes. Our study area in central Europe (Hungary) included 3049 skylark observation points and their 600 m buffer zones. We used a very detailed map (20 × 20 m minimum mapping unit), the Hungarian Ecosystem Basemap, as a land-cover dataset for the calculation of three landscape indices: mean patch size (MPS), mean fractal dimension (MFRACT), and Shannon diversity index (SDI) to describe the landscape structure of the study areas. Generalized linear models were used to analyze the effect of land-cover types and landscape patterns on the abundance of the Eurasian skylark (Alauda arvensis). According to our findings, the proportions of arable land, open sand steppes, closed grassland patches, and shape complexity and size characteristics of these land cover patches have a positive effect on skylark abundance, while the SDI was negatively associated with the skylark population. On the basis of the used statistical model, the abundance density (individuals/km*) of skylarks could be estimated with 37.77% absolute percentage error and 2.12 mean absolute error. We predicted the skylark population density inside the Natura 2000 Special Protected Area of Hungary which is 0–6 individuals/km* and 23746 ± 8968 skylarks. The results can be implemented for the landscape management of rural landscapes, and the method used are adaptable for the density estimation of other farmland bird species in rural landscapes. According to our findings, inside the protected areas should increase the proportion, the average size and shape complexity of arable land, salt steppes and meadows, and closed grassland land cover patches.

Effects of crop sequence and rainfall on population dynamics of Fusarium solani f.sp. phaseoli in soil

1992 ◽  
Vol 70 (10) ◽  
pp. 2005-2008 ◽  
Author(s):  
Robert Hall ◽  
Lana Gay Phillips
Keyword(s):  
Population Dynamics ◽  
Phaseolus Vulgaris ◽  
Population Density ◽  
Fusarium Solani ◽  
Population Densities ◽  
Total Rainfall ◽  
Colony Forming Units ◽  
Bean Crop ◽  
Previous Summer ◽  
Crop Sequence

Evidence is presented that population dynamics of Fusarium solani f.sp. phaseoli in soil depend on the effects of crop sequence and rainfall on parasitic activities of the pathogen. In a rotation trial started in 1978 and conducted over 14 years, population densities (colony-forming units/g) of the fungus in soil remained below 50 in treatments (fallow, repeated corn, repeated soybean) where the preferred host plant (common bean, Phaseolus vulgaris) was not grown. Where bean was grown every 3rd year or every year, population densities reached 475 and 660, respectively, by 1984. Thereafter, population densities of the fungus fluctuated widely from year to year in both rotation and repeated bean treatments. In the rotation treatment, peaks in population density of the pathogen coincided with the years of bean production. In repeated bean plots between 1985 and 1991, population density of the fungus in June was significantly correlated (r = 0.77, p = 0.04) with total rainfall received during the previous summer (June–August). It is postulated that higher rainfall during the growing season of the bean crop stimulated root growth and root infection, leading to the accumulation of higher levels of potential inoculum in infected tissue and the release of higher levels of inoculum into the soil by the following June. Key words: Fusarium solani f.sp. phaseoli, bean, Phaseolus vulgaris, rainfall, crop rotation.

scholarly journals Using Bioacoustics to Examine Vocal Phenology of Neotropical Migratory Birds on a Wild and Scenic River in Arizona

Birds ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 261-274
Author(s):  
Heather L. Bateman ◽  
Sidney B. Riddle ◽  
Erin S. Cubley
Keyword(s):  
Sonoran Desert ◽  
Migratory Birds ◽  
Riparian Forest ◽  
Bird Species ◽  
Migratory Bird ◽  
Bird Diversity ◽  
Yellow Warbler ◽  
Habitat Features ◽  
The Usa ◽  
Vocal Activity

Passive acoustic recorders have been used successfully as automated survey tools to detect terrestrial wildlife. However, few studies have monitored Neotropical migratory bird use of riparian forest habitat using this technology. Within dryland ecosystems, the forests along rivers support high bird diversity. Many bird species of conservation concern require these floodplain forest habitats for foraging, migration stop-overs, and breeding. Few studies have explored the use of acoustic records in riverine systems designated for conservation for their natural resource value via the Wild and Scenic Rivers Act in the USA. Using acoustic recorders, we document vocal activity of four riparian-obligate species (Bell’s Vireo, Vireo bellii; Summer Tanager, Piranga rubra; Yellow Warbler, Setophaga petechial; and Yellow-billed Cuckoo, Coccyzus americanus) to determine species occurrence along a Wild and Scenic River. We established three study reaches along the perennial Lower Verde River, in the Sonoran Desert of central Arizona, USA. Nine acoustic recorders were used over the period of 80–120 days during the summer of 2018. We measured vegetation composition and structure in 100 m2 plots paired with acoustic recorders. Visualizing vocal activity showed that three species were calling and singing at each reach; whereas, one species, the cuckoo, had fewer recordings and occurred later in the summer. We demonstrate the utility of acoustic monitoring even when applied to rare birds in complex riparian habitats. This information is important for land management and conservation efforts concerning these species of interest and identifying important habitat features in Southwestern US riparian woodlands.

Population Densities Allowed Around Dutch SEVESO Establishments

2000 ◽  
Author(s):  
G. M. H. Laheij ◽  
B. J. M. Ale ◽  
J. G. Post
Keyword(s):  
Population Density ◽  
The Netherlands ◽  
Individual Risk ◽  
Population Densities ◽  
Planning Policy ◽  
Relative Contribution ◽  
Societal Risk ◽  
Dangerous Substances ◽  
The Individual ◽  
Uniform Population

Abstract In the Netherlands, the individual risk and societal risk are used in efforts to reduce the number of people exposed to the effect of an accident at an establishment with dangerous substances. To facilitate the societal risk planning policy an investigation was carried out for the Dutch SEVESO establishments to investigate the possibility of determining a generic uniform population density for the zone between the individual risk contours of 10−5 and 10−6 per year. The indicative limit for the societal risk at this density was not to be exceeded. Also there was to be enough space left for a significantly higher population density outside the individual risk contour of 10−6 per year. The RORISC methodology and the actual data for the 124 Dutch SEVESO establishments were used to determine the generic uniform population density. Based on the data available it can be concluded that the maximum allowed uniform population density in the zone between the individual risk contours of 10−5 and 10−6 per year is lower than one person per hectare. At this density there is no space left for a higher population density outside the individual risk contour of 10−6 per year. For uniform population densities the relative contribution to the societal risk has been found significant up to the individual risk contour of 10−7 per year.

scholarly journals Effects of population density on cauliflower crop (Brassica oleracea L. var. botrytis)

1981 ◽  
Vol 38 (1) ◽  
pp. 1-10
Author(s):  
Keigo Minami ◽  
Ricardo Victoria Fº
Keyword(s):  
Population Density ◽  
Brassica Oleracea ◽  
Plant Population ◽  
Population Densities ◽  
Plant Population Density ◽  
Brassica Oleracea L ◽  
Quality Weight

An experiment was carried out to study the effects of the following population densities cauliflowers (plants per ha): 20,833 (0.60 m x 0.80 m), 25,641 (0.60 m x 0.65 m), ....37.037 (0.60 m x 0.45 m) , 55.555 (.0.60 m x 0.30 m), and 111,111 (0,60 m x 0,15 m) ; variety Snow ball. It was concluded that the effects of plant population density are greater on curd quality (weight and size) than on production per ha. The best plant population density to produce cauliflowers curd for Brazil market is from 20,000 to 25,000 plants/ha while for mini-curd is above 55,000 plants/ha.

Relationship between Morphology and Trophic Ecology in an Assemblage of Passerine Birds in Riparian Forests of the Paraná River (Argentina)

2018 ◽  
Vol 11 (1) ◽  
pp. 44-53 ◽  
Author(s):  
Virginia Quiroga ◽  
Rodrigo E. Lorenzón ◽  
Gisela Maglier ◽  
Ana L. Ronchi-Virgolini
Keyword(s):  
Trophic Ecology ◽  
Riparian Forest ◽  
A Priori ◽  
Bird Species ◽  
Morphological Characteristics ◽  
Paraná River ◽  
Riparian Forests ◽  
Phylogenetic Constraint ◽  
Parana River ◽  
Coexisting Species

We describe the ecomorphology of an assemblage of bird species found in riparian forests of the Middle Paraná River, Argentina. We sought to determine (1) the more important morphological characteristics that separate coexisting species, (2) whether such separation was related to the trophic ecology of each species and (3) whether a priori guilds showed morphological similarity. We tested the hypotheses that (a) a species’ morphology is related to the trophic ecology of that species and (b) that species of a priori guilds are morphometrically more similar to each other than to species of different a priori guilds. For this, we considered an assemblage of 29 species of birds from riparian forest that were sampled with mist nets during the 2011 and 2014 breeding seasons. We obtained morphometric measurements of captured individuals and supplemented those data with measurements from museum specimens. Trophic characterisation (diet and trophic microhabitat) was based on a literature review. Results showed a separation of bird species as a function of variables related to trophic ecology (diets and trophic microhabitats) and morphology. After controlling for phylogenetic constraint, species’ morphology partially reflected the trophic ecology of the species, supporting the central hypothesis of the ecomorphological discipline and showing that the use of trophic and morphometric data provides complementary data to improve the guild organisation of riparian bird assemblages.

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