Influence of matrix habitats on the occurrence of insectivorous bird species in Amazonian forest fragments

2005 ◽  
Vol 122 (3) ◽  
pp. 441-451 ◽  
Author(s):  
Marina Antongiovanni ◽  
Jean Paul Metzger
The Condor ◽  
2020 ◽  
Vol 122 (3) ◽  
Author(s):  
Montague H C Neate-Clegg ◽  
Çağan H Şekercioğlu

Abstract The Amazon has a long history of disturbance under subsistence agriculture, but slash-and-burn agriculture is small in scale and has relatively low impact on resident avifauna. More recently, the Amazon has suffered extensive deforestation in favor of cattle ranching and other modern systems of agriculture. Cattle pastures, mechanized agriculture, and even tree plantations have detrimental effects on bird communities, greatly lowering diversity, especially that of primary forest interior specialists. A rising threat to the Amazon is the spread of oil palm plantations that retain few bird species and are not viable alternatives to forest. Embedded within the expanding agropastoral mosaic are forest fragments that have experienced a well-documented loss of diversity. Yet, the matrix can mitigate the recovery of fragmented bird communities depending on the type of secondary regrowth. Connectivity via matrix habitats or forest corridors is critical for the maintenance of forest avifauna. With so many types of land use developing across the Amazon, the “tropical countryside” has potential value for bird diversity. However, evidence suggests that the agropastoral mosaic harbors a small, more homogenized avifauna with few forest species, especially when primary forest is absent from the landscape. For the Amazon Basin’s bird life to be conserved into the future, preservation of large tracts of well-connected primary forest is vital. Tropical countryside dominated by agriculture simply cannot sustain sufficient levels of biodiversity.


1989 ◽  
Vol 19 (0) ◽  
pp. 249-263 ◽  
Author(s):  
Lee H. Harper

SUMMARYMist-net captures of army ant-following bird were monitored during the isolation of central Amazonian forest fragments of 1 ha (n = 5), 10 ha (n = 4) and 100 ha (n = 1). Post-isolation captures of the three obligate ant-following birds Dendrocinela merula, Pithys albifrons, and Gymnopithys rufigula decreased significantly in all fragments. post-isolation captures of four facultative ant-following species were not significantly different in forest fragments of 1 ha and 10 ha, although two species decreased significantly in the 100 ha fragment. Experimental introductions of obligate species into small forest fragments in the absence and presence of introduced Eciton burchelli army ant colonies resulted in significantly greater recaptures of introduced birds when active army ant colonies were present. Of the 105 birds introduced, 58 ' 55%) crossed 100-320 m od dedorested area an were recaptured in continuous forest.


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.


2021 ◽  
Vol 2 (3) ◽  
pp. 1-4
Author(s):  
Maria Cecília Barbosa de Toledo

Green urban areas such as parks, squares, gardens, and forest fragments present a large diversity of uses and conservation objectives. These spaces provide resources for many species of birds that are confronted with the necessity of living in proximity to humans. It is assumed that bird species that acquire resources in urban environments live in a constant state of fear to guarantee survival and reproduction. In this context, the objective of this study was to evaluate the tolerance of birds with respect to human presence in two distinct conditions, rural areas (low level of human presence) and urban areas (high level of human presence). The fieldwork was conducted in a city in the Southeast region of Brazil, and the methodology used the alert distance and flight initiation measurements based on the approach of an observer to the individual bird being focused. Our results suggest that individuals observed in urban areas rely on shorter alert and escape distances, especially males, adults, and birds that forage in interspecific flocks. We discuss the challenges and strategies with respect to escape characteristics of urban birds, with special focus on the economic escape theory. In general, our results support those from studies conducted in other urban areas in different biogeographic regions, and they will aid in comprehending the impacts caused by the increase in urban areas around the world.


1998 ◽  
Vol 282 (5394) ◽  
pp. 1611a-1611 ◽  
Author(s):  
D. Cowles;

2019 ◽  
Vol 5 (6) ◽  
pp. eaav6699 ◽  
Author(s):  
Carine Emer ◽  
Mauro Galetti ◽  
Marco A. Pizo ◽  
Pedro Jordano ◽  
Miguel Verdú

Species on Earth are interconnected with each other through ecological interactions. Defaunation can erode those connections, yet we lack evolutionary predictions about the consequences of losing interactions in human-modified ecosystems. We quantified the fate of the evolutionary history of avian–seed dispersal interactions across tropical forest fragments by combining the evolutionary distinctness of the pairwise-partner species, a proxy to their unique functional features. Both large-seeded plant and large-bodied bird species showed the highest evolutionary distinctness. We estimate a loss of 3.5 to 4.7 × 104 million years of cumulative evolutionary history of interactions due to defaunation. Bird-driven local extinctions mainly erode the most evolutionarily distinct interactions. However, the persistence of less evolutionarily distinct bird species in defaunated areas exerts a phylogenetic rescue effect through seed dispersal of evolutionarily distinct plant species.


2002 ◽  
Vol 16 (3) ◽  
pp. 605-618 ◽  
Author(s):  
William F. Laurance ◽  
Thomas E. Lovejoy ◽  
Heraldo L. Vasconcelos ◽  
Emilio M. Bruna ◽  
Raphael K. Didham ◽  
...  

2011 ◽  
Vol 144 (2) ◽  
pp. 830-835 ◽  
Author(s):  
Paul R. Gagnon ◽  
Emilio M. Bruna ◽  
Paulo Rubim ◽  
Maria Rosa Darrigo ◽  
Ramon C. Littell ◽  
...  

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