scholarly journals Avian diversity in a fragmented landscape of central Indian forests (Bhopal Forest Circle)

2021 ◽  
Vol 13 (5) ◽  
pp. 18177-18188
Author(s):  
Amit Kumar ◽  
Yogesh Dubey ◽  
Advait Edgaonkar

With increasing fragmentation of natural areas and a dramatic reduction of forest cover in several parts of the world, quantifying the impact of such changes on species richness and community dynamics has been a subject of much concern.  Therefore, this study intends to assess avifaunal biodiversity in fragmented forests.  Forest patches between the sizes of 10ha and 700ha were identified in Bhopal Forest Circle (BFC), which covers the Vindhyan plateau.  Forest patches were classified based on their size and degree of isolation.  A sample of 21 forest fragments was selected using proportional sampling.  Bird surveys were conducted using the point count method at each site.  Three replicates were taken at each site.  Avian species richness of each patch was calculated.  The results suggest that species richness is positively associated with the size of the forest patches.  Larger forest patches such as Binapur (166ha, Chao 1= 73), Sayar (107ha, Chao 1= 78) and Kalyanpura (133ha, Chao 1= 80) had relatively high species richness, except for patches including Narsinghgarh (393ha, Chao 1= 28) and Singota (184ha, Chao 1= 45) with high levels of anthropogenic disturbance.  Smaller forest patches were found to have fewer bird species, although small forest patches with lesser degrees of anthropogenic disturbance such as Lalghati (99ha, Chao 1 = 62), Lasudli (16ha, Chao 1 = 65), Ghot (36ha, Chao 1 = 53), and Nasipur (23ha, Chao 1 =52) were more diverse than other patches.  These patches were more protected due to being sacred groves (Lalghati and Lasudli) or under private ownership (Ghot and Nasipur).  A total of 131 bird species were recorded from all the sampled forest patches.  These results suggest that forest patches embedded in an agrarian landscape play a vital role in conserving biodiversity, hence conservation efforts should also be focused on these forest fragments.

2021 ◽  
pp. 1-10
Author(s):  
Carlos M. Delgado-Martínez ◽  
Fredy Alvarado ◽  
Melanie Kolb ◽  
Eduardo Mendoza

Abstract Great attention has been drawn to the impacts of habitat deforestation and fragmentation on wildlife species richness. In contrast, much less attention has been paid to assessing the impacts of chronic anthropogenic disturbance on wildlife species composition and behaviour. We focused on natural small rock pools (sartenejas), which concentrate vertebrate activity due to habitat’s water limitation, to assess the impact of chronic anthropogenic disturbance on the species richness, diversity, composition, and behaviour of medium and large-sized birds and mammals in the highly biodiverse forests of Calakmul, southern Mexico. Camera trapping records of fauna using sartenejas within and outside the Calakmul Biosphere Reserve (CBR) showed that there were no effects on species richness, but contrasts emerged when comparing species diversity, composition, and behaviour. These effects differed between birds and mammals and between species: (1) bird diversity was greater outside the CBR, but mammal diversity was greater within and (2) the daily activity patterns of birds differed slightly within and outside the CBR but strongly contrasted in mammals. Our study highlights that even in areas supporting extensive forest cover, small-scale chronic anthropogenic disturbances can have pervasive negative effects on wildlife and that these effects contrast between animal groups.


2004 ◽  
Vol 76 (2) ◽  
pp. 429-434 ◽  
Author(s):  
Luiz dos Anjos

Bird communities were studied in two types of fragmented habitat of Atlantic forest in the State of Paraná, southern Brazil; one consisted of forest fragments that were created as a result of human activities (forest remnants), the other consisted of a set of naturally occurring forest fragments (forest patches). Using quantitative data obtained by the point counts method in 3 forest patches and 3 forest remnants during one year, species richness and relative abundance were compared in those habitats, considering species groups according to their general feeding habits. Insectivores, omnivores, and frugivores presented similar general tendencies in both habitats (decrease of species number with decreasing size and increasing isolation of forest fragment). However, these tendencies were different, when considering the relative abundance data: the trunk insectivores presented the highest value in the smallest patch while the lowest relative abundance was in the smallest remnant. In the naturally fragmented landscape, time permitted that the loss of some species of trunk insectivores be compensated for the increase in abundance of other species. In contrast, the remnants essentially represented newly formed islands that are not yet at equilibrium and where future species losses would make them similar to the patches.


2013 ◽  
Vol 103 (2) ◽  
pp. 85-96 ◽  
Author(s):  
Lahert W. Lobo-Araújo ◽  
Mário T. F. Toledo ◽  
Márcio A. Efe ◽  
Ana C. M. Malhado ◽  
Marcos V. C. Vital ◽  
...  

The Pernambuco Center of Endemism (PCE) in northeastern Brazil is highly fragmented and degraded. Despite its potential conservation importance the bird fauna in this area is still relatively unknown and there are many remnant fragments that have not been systematically surveyed. Here, we report the results of bird surveys in five forest fragments (one pioneer, two ombrophilous and two seasonal). In total, 162 taxa were recorded, 12 of which are endemic to the PCE. The frequency of endangered species was lower than what has been reported in studies from the same area and most of the taxa considered to be at risk of extinction were sub-species of uncertain taxonomic validity. The comparatively low number of endemic/threatened species may be due to the small size of the fragments in the present study - a consequence of the high levels of habitat loss in this region. Analysis of species richness patterns indicates that ombrophilous forest fragments are acting as refuges for those bird species that are most sensitive to environmental degradation.


SURG Journal ◽  
2017 ◽  
Vol 9 (1) ◽  
pp. 5-13
Author(s):  
Adrian Helmers ◽  
Alexis Platek ◽  
Melissa Ponte ◽  
Natalie Secen ◽  
Karl Cottenie

This study quantified the impact of human activity on aquatic and shoreline plant species richness. We hypothesized that human activity at the shoreline would negatively impact plant species richness and that the extent of the impact would depend on the intensity of human activity. To test this, we sampled 11 lakes in Algonquin Provincial Park, of which five permitted motorboat access, and five permitted canoe access and prohibited motorboat access. The remaining lake, which had no designated access point for boats and was only accessible to researchers, acted as a control. To assess the impact of anthropogenic disturbance at each lake, we measured plant species richness in three 10 m by 2 m plots: a first plot at the access point, assumed to be the site of highest disturbance; a second at the site of intermediate disturbance, 30 m down shore from the access point; and a third at the site of lowest disturbance, 60 m down shore from the access point. We found a significant negative relationship between the level of disturbance and plant species richness, both in the motorboat-accessible and canoe access-only lakes. The control lake exhibited no correlation between disturbance level and plant species richness. However, there was no significant difference between motorboat-accessible and canoe access-only lakes in the relationship between disturbance level and plant species richness. Overall, this study highlights the consequences of anthropogenic disturbance on freshwater aquatic and shoreline plant communities, and provides a framework for future management and rehabilitation strategies.


2002 ◽  
Vol 8 (2) ◽  
pp. 82 ◽  
Author(s):  
Michael A. MacDonald ◽  
Robert J. Taylor ◽  
Steven G. Candy

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.


2012 ◽  
Vol 26 (6) ◽  
pp. 1100-1111 ◽  
Author(s):  
Alexandre Camargo Martensen ◽  
Milton Cezar Ribeiro ◽  
Cristina Banks-Leite ◽  
Paulo Inácio Prado ◽  
Jean Paul Metzger

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Ravi Jambhekar ◽  
Kulbhushansingh Suryawanshi ◽  
Harini Nagendra

Abstract Urbanization is one of the major causes of biodiversity loss worldwide. Some species are able to adapt to urbanization, whereas others perish. Studies on long-term effects of the impact of urbanization on species diversity and abundance patterns are especially lacking from tropical cities. We seek to assess the relationship between urbanization and species richness of lake-dependent birds in Bangalore, a tropical mega-city in Southern India. We specifically ask: (i) How is bird species richness related to the size of the lake? (ii) How is bird species richness in Bangalore’s lakes related to the degree of urbanization? We used data from 2014 to 2019, collected from eBird—an online database that collates information on bird observations globally. Both lake area and distance from the city centre are correlated to species richness, with larger lakes supporting more bird species. As distance from the city centre increased (i.e. urbanization decreases), bird richness increased. Overall, in the city of Bangalore, migratory birds have declined while many lake-dependent resident birds seem to be increasing over the past 5 years. We hypothesize that birds that roost and nest in trees appear to be increasing. To confirm this, further research taking a trait-based approach is required. Urbanization appears to have species-specific impacts on lake-dependent birds in this tropical city, with certain groups of birds faring better than others. This research adds to the significant paucity of studies of the impact of urbanization on biodiversity in the urban tropics.


2021 ◽  
Vol 14 ◽  
pp. 194008292110499
Author(s):  
Marisela Martínez-Ruiz ◽  
Miguel A. De Labra-Hernández ◽  
Fernando César Gonçalves Bonfim ◽  
Eliana Cazetta

Background and Research Aims: Habitat amount plays an important role in determining the presence and abundance of bird species in modified landscapes, whereas habitat fragmentation has shown little effects. Toucans (Ramphastidae) and parrots (Psittacidae) are large-bodied primary consumers and among the most representative birds in Neotropical forests. They are highly sensitive to habitat loss; nevertheless, their response to fragmentation has been poorly assessed leading to contradictory results. Here, we evaluate the influence of landscape structure on toucans and parrots in the tropical forest of Los Tuxtlas, Mexico. Methods: We censused birds in 12 landscapes of Los Tuxtlas and used a multi-scale landscape approach to assess the influence of landscape composition and configuration on the number of individuals of toucans and parrots. Results: We found that the most important and positive predictor of toucans and parrots was the amount of primary forest cover in the landscape. Forest fragmentation had positive effects on the number of toucan individuals, whereas parrots had negative responses to patch density but positive responses to edge density in the landscape. Conclusion: Our results suggest that primary forest loss is the main threat for toucans and parrots in Los Tuxtlas. Implications for conservation: Future conservation and land management must consider the protection of large and small remnants of primary forest and avoid additional forest loss in order to preserve toucan and parrots and their functional roles in human-modified Neotropical landscapes.


2008 ◽  
Vol 18 (2) ◽  
pp. 164-180 ◽  
Author(s):  
Huw Lloyd

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.


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