scholarly journals Abundance and patterns of rarity of Polylepis birds in the Cordillera Vilcanota, southern Perú: implications for habitat management strategies

2008 ◽  
Vol 18 (2) ◽  
pp. 164-180 ◽  
Author(s):  
Huw Lloyd
Keyword(s):  
Species Richness ◽  
Habitat Loss ◽  
Habitat Management ◽  
Habitat Restoration ◽  
Management Strategies ◽  
Distance Sampling ◽  
Bird Species ◽  
Bird Community ◽  
Forest Patches ◽  
Lowland Forest

AbstractPoint count distance sampling surveys were conducted at three sites in the Cordillera Vilcanota to determine whether variation in high-Andean species richness, diversity and abundance was a reflection of Polylepis habitat quantity. Bird community and abundance measures revealed that there was considerably variation in bird species richness, diversity and mean encounter rates between large, medium, and small forest patches. Densities of Polylepis-dependent bird species (including five globally-threatened and eight restricted-range species) were greater in larger forest patches and differed significantly between different patch size categories. Density estimates for matrix-dependent species were higher in smaller Polylepis patches indicating that the matrix exerts an influence on bird species composition and abundance in remnant Polylepis forests, particularly smaller patches. Comparison of lowland forest habitat specialists using three categories of rarity revealed that between 19–22% of all Polylepis-dependent species were intrinsically rare within larger forest patches, and a greater number (34–74%) were rare in smaller forest patches. Population estimates for all species, in particular for all threatened species, were extremely low, numbering ⩽ 10 individuals at nine of the ten sites examined. The results suggest that declines in the densities of certain Polylepis birds may be predictable following habitat loss and that these patterns of rarity should govern population recovery goals through appropriate habitat restoration strategies. Such strategies are urgently required and must be designed to prevent further habitat loss, and to increase Polylepis habitat quantity to boost threatened bird populations in the Cordillera Vilcanota.Evaluaciones de distancias de puntos de conteo fueron conducidas en tres lugares en la Cordillera Vilcanota para determinar si la variación en la riqueza, diversidad y abundancia de las especies de los Andes altos, era un reflejo de la cantidad de hábitats de Polylepis. La comunidad de aves y su abundancia revelaron que hubo una considerable variación en la riqueza de especies, diversidad y la media encontrada en rangos parches de bosque comprendidos entre grandes, medios y pequeãos. La densidad de especies de aves dependientes de Polylepis (incluyendo cinco amenazados globalmente y ocho especies con rango restringido) fueron mayores en parches grandes de bosque y difirieron significativamente entre diferentes categorías de tamaãos de parche. La densidad estimada para especies matriz-dependientes fue mayor en pequeãos parches de Polylepis indicando que la matriz ejerce una influencia en la composición de especies de aves y abundancia en vestigios de bosques de Polylepis, particularmente parches pequeãos. En comparación con especialistas de hábitat de bosque bajo, empleando tres categorías de rareza revelaron que entre 19–22% de todos las especies dependientes de Polylepis fueron intrínsicamente raras dentro de parches grandes de bosque, y un número mayor (34–74%) fueron raras en los parches pequeãos de bosque. La población estimada para todas las especies, en particular para todas las especies amenazadas, fue extremadamente baja, contando ⩽ 10 individuos en nueve de los 10 sitios examinados. El resultado sugiere que la disminución en la densidad de ciertas aves de Polylepis se podría predecir después de la pérdida de hábitat y que esos patrones de rareza podrían servir como objetivos para la recuperación de la población a través de estrategias de restauración de hábitats apropiados. Este tipo de estrategias son requeridas con urgencia y deberían estar diseãadas para prevenir futuras pérdidas de hábitats, incrementar la cantidad de hábitat de Polylepis para aumentar la población de aves amenazadas en la Cordillera Vilcanota.

scholarly journals Road networks predict human influence on Amazonian bird communities

2014 ◽  
Vol 281 (1795) ◽  
pp. 20141742 ◽  
Author(s):  
Sadia E. Ahmed ◽  
Alexander C. Lees ◽  
Nárgila G. Moura ◽  
Toby A. Gardner ◽  
Jos Barlow ◽  
...  
Keyword(s):  
Species Richness ◽  
Habitat Loss ◽  
Edge Effects ◽  
Forest Cover ◽  
Road Networks ◽  
Bird Species ◽  
Bird Community ◽  
Selective Logging ◽  
Forest Bird ◽  
Bird Richness

Road building can lead to significant deleterious impacts on biodiversity, varying from direct road-kill mortality and direct habitat loss associated with road construction, to more subtle indirect impacts from edge effects and fragmentation. However, little work has been done to evaluate the specific effects of road networks and biodiversity loss beyond the more generalized effects of habitat loss. Here, we compared forest bird species richness and composition in the municipalities of Santarém and Belterra in Pará state, eastern Brazilian Amazon, with a road network metric called ‘roadless volume (RV)’ at the scale of small hydrological catchments (averaging 3721 ha). We found a significant positive relationship between RV and both forest bird richness and the average number of unique species (species represented by a single record) recorded at each site. Forest bird community composition was also significantly affected by RV. Moreover, there was no significant correlation between RV and forest cover, suggesting that road networks may impact biodiversity independently of changes in forest cover. However, variance partitioning analysis indicated that RV has partially independent and therefore additive effects, suggesting that RV and forest cover are best used in a complementary manner to investigate changes in biodiversity. Road impacts on avian species richness and composition independent of habitat loss may result from road-dependent habitat disturbance and fragmentation effects that are not captured by total percentage habitat cover, such as selective logging, fire, hunting, traffic disturbance, edge effects and road-induced fragmentation.

scholarly journals Congruence between breeding and wintering biodiversity hotspots: A case study in farmlands of Western Poland

2019 ◽  
Vol 4 (2) ◽  
pp. 75-83
Author(s):  
Federico Morelli ◽  
Zbigniew Kwieciński ◽  
Piotr Indykiewicz ◽  
Łukasz Jankowiak ◽  
Paweł Szymański ◽  
...  
Keyword(s):  
Species Richness ◽  
Protected Areas ◽  
Functional Diversity ◽  
Conservation Status ◽  
Bird Species ◽  
Bird Community ◽  
Bird Diversity ◽  
Human Beings ◽  
Complete Representation ◽  
Evolutionary Distinctiveness

Abstract Farmland landscapes are recognized as important ecosystems, not only for their rich biodiversity but equally so for the human beings who live and work in these places. However, biodiversity varies among sites (spatial change) and among seasons (temporal change). In this work, we tested the hypothesis that bird diversity hotspots distribution for breeding is congruent with bird diversity hotspots for wintering season, focusing also the representation of protected areas for the conservation of local hotspots. We proposed a framework based on the use of species richness, functional diversity, and evolutionary distinctiveness to characterize avian communities. Although our findings show that the spatial distribution of local bird hotspots differed slightly between seasons, the protected areas’ representation was similar in both seasons. Protected areas covered 65% of the most important zones for breeding and 71% for the wintering season in the farmland studied. Functional diversity showed similar patterns as did bird species richness, but this measure can be most effective for highlighting differences on bird community composition. Evolutionary distinctiveness was less congruent with species richness and functional diversity, among seasons. Our findings suggest that inter-seasonal spatial congruence of local hotspots can be considered as suitable areas upon which to concentrate greater conservation efforts. However, even considering the relative congruence of avian diversity metrics at a local spatial scale, simultaneous analysis of protected areas while inter-seasonally considering hotspots, can provide a more complete representation of ecosystems for assessing the conservation status and designating priority areas.

scholarly journals Fire effects on the composition of a bird community in an amazonian Savanna (Brazil)

2005 ◽  
Vol 65 (4) ◽  
pp. 683-695 ◽  
Author(s):  
R. Cintra ◽  
T. M. Sanaiotti
Keyword(s):  
Species Richness ◽  
Community Composition ◽  
Spatial Scales ◽  
Bird Species ◽  
Bird Community ◽  
Fire Effects ◽  
Bird Abundance ◽  
Bird Species Richness ◽  
Byrsonima Crassifolia ◽  
Mist Net

The effects of fire on the composition of a bird community were investigated in an Amazonian savanna near Alter-do-Chão, Pará (Brazil). Mist-net captures and visual counts were used to assess species richness and bird abundance pre- and post-fire in an approximately 20 ha area. Visual counts along transects were used to survey birds in an approximately 2000 ha area in a nearby area. Results using the same method of ordination analysis (multidimensional scaling) showed significant effects of fire in the 20 ha and 2000 ha areas and strongly suggest direct effects on bird community composition. However, the effects were different at different spatial scales and/or in different years, indicating that the effects of fire vary spatially and/or temporally. Bird community composition pre-fire was significantly different from that found post-fire. Using multiple regression analysis it was found that the numbers of burned and unburned trees were not significantly related to either bird species richness or bird abundance. Two months after the fire, neither bird species richness nor bird abundance was significantly related to the number of flowering trees (Lafoensia pacari) or fruiting trees (Byrsonima crassifolia). Since fire is an annual event in Alter-do-Chão and is becoming frequent in the entire Amazon, bird community composition in affected areas could be constantly changing in time and space.

Bird assemblages in wildlife habitat strips in a Tasmanian plantation matrix

2002 ◽  
Vol 8 (2) ◽  
pp. 82 ◽  
Author(s):  
Michael A. MacDonald ◽  
Robert J. Taylor ◽  
Steven G. Candy
Keyword(s):  
Species Richness ◽  
Bird Species ◽  
Wildlife Habitat ◽  
Native Forest ◽  
Total Abundance ◽  
Forest Patches ◽  
Bird Species Richness ◽  
Linear Forest ◽  
Significant Difference ◽  
Production Forests

In Tasmania, a system of 100 m wide strips of native forest, referred to as wildlife habitat strips, is retained within production forest, including plantations. Thirty-nine points in 18 wildlife habitat strips within both eucalypt and pine plantations (which were not differentiated for the purposes of the present study) were paired with points in nearby extensive native forest and surveyed for birds. At non-riparian sites (upper slopes and ridges), bird species richness and total abundance were both significantly lower in habitat strips than in controls. This difference is quantitative rather than qualitative, as ordination did not distinguish strip sites and controls, and no species were obviously absent from habitat strips. Riparian zones showed no significant difference in species richness and total abundance between habitat strips and controls. Species richness and total abundance relative to controls increased as wildlife habitat strip length increased over the measured range (0.4-2.1 km). It is thought that this may be because birds perceive strips as linear forest patches rather than corridors, so that there may be a habitat area effect. Other strip characteristics such as width and plantation age were not significant in riparian areas, but may be important on upper slopes and ridges, and the former will affect strip area. Wildlife habitat strips appear to be a valuable component of a conservation programme for birds in production forests in Tasmania.

scholarly journals Spatial and Temporal Dependency of NDVI Satellite Imagery in Predicting Bird Diversity over France

2018 ◽  
Vol 10 (7) ◽  
pp. 1136 ◽  
Author(s):  
Sébastien Bonthoux ◽  
Solenne Lefèvre ◽  
Pierre-Alexis Herrault ◽  
David Sheeren
Keyword(s):  
Species Richness ◽  
Satellite Imagery ◽  
Bird Species ◽  
Bird Community ◽  
Additive Models ◽  
Landscape Patterns ◽  
Community Patterns ◽  
Bird Species Richness ◽  
Acquisition Period ◽  
Time Period

Continuous-based predictors of habitat characteristics derived from satellite imagery are increasingly used in species distribution models (SDM). This is especially the case of Normalized Difference Vegetation Index (NDVI) which provides estimates of vegetation productivity and heterogeneity. However, when NDVI predictors are incorporated into SDM, synchrony between biological observations and image acquisition must be questionned. Due to seasonal variations of NDVI during the year, landscape patterns of habitats are revealed differently from one date to another leading to variations in models’ performance. In this paper, we investigated the influence of acquisition time period of NDVI to explain and predict bird community patterns over France. We examined if the NDVI acquisition period that best fit the bird data depends on the dominant land cover context. We also compared models based on single time period of NDVI with one model built from the Dynamic Habitat Index (DHI) components which summarize variations in vegetation phenology throughout the year from the fraction of radiation absorbed by the canopy (fPAR). Bird species richness was calculated as response variable for 759 plots of 4 km2 from the French Breeding Bird Survey. Bird specialists and generalists to habitat were considered. NDVI and DHI predictors were both derived from MODIS products. For NDVI, five time periods in 2010 were compared, from late winter to begin of autumn. A climate predictor was also used and Generalized Additive Models were fitted to explain and predict bird species richness. Results showed that NDVI-based proxies of dominant habitat identity and spatial heterogeneity explain more bird community patterns than DHI-based proxies of annual productivity and seasonnality. We also found that models’ performance was both time and context-dependent, varying according to the bird groups. In general, best time period of NDVI did not match with the acquisition period of bird data because in case of synchrony, differences in habitats are less pronounced. These findings suggest that the most powerful approach to estimate bird community patterns is the simplest one. It only requires NDVI predictors from a single appropriate time period, in addition to climate, which makes the approach very operational.

scholarly journals A rapid assessment of logging effects on bird species in Kelantan forests areas, Malaysia

2015 ◽  
Author(s):  
Saber Ghasemi
Keyword(s):  
Rain Forest ◽  
Rapid Assessment ◽  
Distance Sampling ◽  
Bird Species ◽  
Secondary Data ◽  
Critically Endangered ◽  
Survey Method ◽  
Lowland Forest ◽  
Forest Reserve ◽  
Logging Effects

Kelantan Forest Areas (KFA) are known to be the major portion of Taman Negara National Park, and it has been identified as an Environmentally Sensitive Area (ESA) rank 1 under Malaysia’s National Physical Plan (NPP). Since access to the forest areas is often lacking and vital forest information are often inadequate, this study aims to find a baseline data for macro EIA of KFA. This study consists of rapid assessment of logging effects on bird species. Based on the study, Kelantan forests are divided into (1) lowland evergreen rain forest, (2) lower mountain rain forest and (3) upper mountain rain forest, using general vegetation forms. A total of 321 species of birds were recorded in KFA using data collection from related agencies, Mist-netting Method, Transect survey Method (Distance Sampling Method; Point Count Method) and Secondary data. Out of this number, 220, 49, 7 and 1 species were falls under totally protected, nearly threatened, vulnerable and critically endangered categories, respectively. Out of the total recorded species, a total of 155, 292 and 128 species were recorded in lowland evergreen rain forest reserves, lower mountain rain forest reserve and upper Kelantan mountain rain forest respectively. The blue-banded kingfisher Alcedo euryzonia in the list of Kelantan birds was fall under critically endangered status. A total of 83 species were observed commonly in 3 kinds of habitat, 20 species were recorded only in Kelantan lowland forest reserve, which species Jambu fruit-dove was fall under nearly threatened. Furthermore, a total of 5 species were recorded just in upper mountain Kelantan rain forest. This study considered that Kelantan forests could be one of the `megadiversity’ places in Malaysia, and effects of logging on wildlife species as well as birds were cleared.

scholarly journals A rapid assessment of logging effects on bird species in Kelantan forests areas, Malaysia

2015 ◽  
Author(s):  
Saber Ghasemi
Keyword(s):  
Rain Forest ◽  
Rapid Assessment ◽  
Distance Sampling ◽  
Bird Species ◽  
Secondary Data ◽  
Critically Endangered ◽  
Survey Method ◽  
Lowland Forest ◽  
Forest Reserve ◽  
Logging Effects

Kelantan Forest Areas (KFA) are known to be the major portion of Taman Negara National Park, and it has been identified as an Environmentally Sensitive Area (ESA) rank 1 under Malaysia’s National Physical Plan (NPP). Since access to the forest areas is often lacking and vital forest information are often inadequate, this study aims to find a baseline data for macro EIA of KFA. This study consists of rapid assessment of logging effects on bird species. Based on the study, Kelantan forests are divided into (1) lowland evergreen rain forest, (2) lower mountain rain forest and (3) upper mountain rain forest, using general vegetation forms. A total of 321 species of birds were recorded in KFA using data collection from related agencies, Mist-netting Method, Transect survey Method (Distance Sampling Method; Point Count Method) and Secondary data. Out of this number, 220, 49, 7 and 1 species were falls under totally protected, nearly threatened, vulnerable and critically endangered categories, respectively. Out of the total recorded species, a total of 155, 292 and 128 species were recorded in lowland evergreen rain forest reserves, lower mountain rain forest reserve and upper Kelantan mountain rain forest respectively. The blue-banded kingfisher Alcedo euryzonia in the list of Kelantan birds was fall under critically endangered status. A total of 83 species were observed commonly in 3 kinds of habitat, 20 species were recorded only in Kelantan lowland forest reserve, which species Jambu fruit-dove was fall under nearly threatened. Furthermore, a total of 5 species were recorded just in upper mountain Kelantan rain forest. This study considered that Kelantan forests could be one of the `megadiversity’ places in Malaysia, and effects of logging on wildlife species as well as birds were cleared.

Bird occupancy and richness in ponderosa pine forests with contrasting forest structure and fire historyThis article is one of a selection of papers from the Special Forum on Ecological Studies in Interior Ponderosa Pine — First Findings from Blacks Mountain Interdisciplinary Research.

2008 ◽  
Vol 38 (5) ◽  
pp. 936-942 ◽  
Author(s):  
T. Luke George ◽  
Steve Zack
Keyword(s):  
Species Richness ◽  
Ponderosa Pine ◽  
Prescribed Burning ◽  
Bird Species ◽  
Bird Community ◽  
American Robin ◽  
Point Counts ◽  
Ponderosa Pine Forests ◽  
Silvicultural Treatments ◽  
Silvicultural Treatment

We compared the effects of two contrasting silvicultural treatments and prescribed fire on bird occupancy at Blacks Mountain Experimental Forest. Each silvicultural treatment was applied to two approximately 100 ha units within each of three blocks. Prescribed burning was applied to one-half of each silvicultural treatment in a split-plot design. Occupancy was estimated at eight points in each plot for 11 bird species and three foraging guilds (bark gleaners, woodpeckers, and foliage gleaners). The frequencies of species detections on the point counts were used to estimate species richness on each plot. Occupancy did not differ among treatments for any of the guilds. Four of the 11 bird species, the American robin ( Turdus migratorius L., 1766), the chipping sparrow ( Spizella passerina (Bechstein, 1798)), the white-breasted nuthatch ( Sitta carolinensis Latham, 1790), and the western tanager ( Piranga ludoviciana (A. Wilson, 1811)), showed responses to the treatments. Species richness did not differ between the silvicultural or the burn treatments. The general lack of response of the bird community to the silvicultural and burn treatments is likely a result of the relatively large size of the trees and snags retained on both silvicultural treatments, the low intensity of the prescribed burns, and the lack of a strong contrast in tree density between the silvicultural treatments.

scholarly journals Variation within the Bird Community of a Rehabilitated Urban Environment, Case of the Félix Houphouët-Boigny University Campus (Côte d'Ivoire)

2021 ◽  
Vol 9 (4) ◽  
Author(s):  
Ekoun Michael KONAN ◽  
Valérie Florence GUETONDE ◽  
Coffi Jean Magloire NIAMIEN ◽  
Kouassi Hilaire YAOKOKORE-BEIBRO
Keyword(s):  
Species Richness ◽  
Ecological Impact ◽  
Bird Species ◽  
Bird Community ◽  
University Campus ◽  
Significant Drop ◽  
Bubulcus Ibis ◽  
Total Species Richness ◽  
Ploceus Cucullatus ◽  
Total Species

In order to understand the ecological impact of the rehabilitation of the Félix Houphouët-Boigny University Campus on the bird community, a study was carried out over two months (October-November 2016). The ornithological inventory carried out by the IPA method in five different habitats identified on the campus gave a total species richness of 51 bird species of 41 genera, 27 families and 13 orders for 1374 birds, with H' = 2.93 and J = 0.74. Five species dominate the population (819 individuals, Fr = 59, 61%). These are Bubulcus ibis (9.32 %), Apus affinis (8.95 %), Corvus albus (19.94 %), Ploceus cucullatus (10.48 %), Lonchura cucullata (10.92 %). The most diversified habitat is the Habitations (26 bird species), while the most abundant is the Brush (416 individuals). Only seven species are common to all sampled habitats. Thus, 12 species observed on campus formerly could not be observed during the present study. Similarly, 18 species observed in this study were not observed in the previous study. The profound transformation of the environment following the rehabilitation has led to a slight increase in diversity but a significant drop in numbers. It is therefore important to better understand the different interactions between the components of the habitat and the various species involved. Such data would be crucial in urban planning policies.

scholarly journals Consistency in bird community assembly over medium-term along rural-urban gradients in Argentina

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Lucas M. Leveau
Keyword(s):  
Species Richness ◽  
Community Assembly ◽  
Rural Areas ◽  
Urban Areas ◽  
Environmental Filtering ◽  
Bird Species ◽  
Bird Community ◽  
Bird Communities ◽  
Assembly Rules ◽  
Urban Habitats

Abstract Background The analysis of bird community assembly rules is fundamental to understand which mechanisms determine the composition of bird species in urban areas. However, the long-term variation of community assembly rules has not been analyzed yet. The objectives of this study are (1) to analyze the variation of community assembly rules along rural-urban gradients of three cities in central Argentina and (2) to compare the patterns of community assembly between two periods separated by 6 years. Bird surveys were performed along transects in urban, suburban, and rural habitats during 2011 and 2017. Departures from null models that took into account differences in species richness (standardized effect size, SES) were calculated for functional and phylogenetic diversities. Results A total of 57 species were recorded. Bird species richness was higher in suburban than in urban and rural habitats. SES of functional diversity increased over the years and was significantly lower in urban habitats than in rural habitats, showing a pattern of functional clustering in the most urbanized areas and functional randomness in rural ones. Phylogenetic diversity was higher in both suburban and urban habitats than rural ones, and the phylogenetic clustering in rural bird assemblages changed to randomness in suburban and urban habitats. Conclusions Bird communities in urban habitats were phylogenetically random and functionally clustered, evidencing environmental filtering by urbanization. In contrast, bird communities in rural areas tended to be phylogenetically clustered, evidencing that certain clades are adapted to rural areas. The processes structuring bird communities along rural-urban gradients were consistent between the 2 years compared.

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