scholarly journals Effects of forest fragmentation on amazonian understory bird communities

1989 ◽  
Vol 19 (0) ◽  
pp. 215-241 ◽  
Author(s):  
Richard O. Bierregaard Jr ◽  
Thomas Ε. Lovejoy

SUMMARYData form an intensive mist-netting mark-recapture program in the central Amazon demostrate significant changes in the undesrtory avian community in isolate patches of 1 and 10 ha of terra firme forest. Following isolation, capture rates increase significantly as birds fleeing the felled forest entered the. newly formed forest fragments. Movement to and from the reserve is restricted, as witnessed by an increase in recapture percentages following isolation. Species of birds that axe. obligate army ant followers disappeared at the time the surrounding habitat was removed from 1 - and 10 - ha areas. The complex mixed-species insectivorous flocks typical of Amazonian forests deteriorated within 2 years of isolation of 1 - and 10 - ha forest fragments. Several species of mid-story insectivores changed their foraging behavior after isolation of small forest reserves.

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.


2015 ◽  
Vol 75 (3 suppl 1) ◽  
pp. 238-249 ◽  
Author(s):  
ACC. Pantoja ◽  
AL. Ilkiu-Borges ◽  
ACC. Tavares-Martins ◽  
ET. Garcia

Abstract Microclimatic conditions of tropical forest favour the high richness of bryophytes, which by being sensitive to environmental changes, are important indicators of habitat conditions. The aim of this study was to determine the richness and species composition of the bryophyte flora in fragments of terra firme forest on the great curve of the Xingu River, Pará state, Brazil. The collections were made in August and September 2012 in 14 fragments, in which were installed two plots per fragment, one at the edge and one inside, measuring 10 × 10 m each. The results showed 77 species in 45 genera and 18 families. Lejeunea setiloba Spruce and Marchesinia brachiata (Sw.) Schiffn. are new records for Pará state. The richness families in this study were the ones typically found in tropical forest surveys. A high richness of rare species in comparison to common ones, a pattern usually observed for plants in tropical forests was not reported in this study, probably due to historical fragmentation and disturbance in the area. The richness and species composition were determined mainly by the physiognomic characteristics of the studied forest fragments.


2021 ◽  
Vol 51 (3) ◽  
pp. 214-223
Author(s):  
Maria Eliene Maia Braga CÂNDIDO ◽  
Patrícia Nakayama MIRANDA ◽  
Elder Ferreira MORATO

ABSTRACT Riparian forests are important ecosystems that support an enormous biodiversity in Brazil. Despite being protected under Brazilian legislation, these forests suffer great impact from the fragmentation of habitats. Orchid bees are a key group of pollinators in the Neotropical region, yet few data are available on the assamblage structure of these bees in riparian forests. We evaluated the role of fragments of riparian and terra-firme forest on the conservation and maintenance of orchid bees in an urban landscape in the southwestern Amazon basin. Specifically, we evaluated whether bee assemblages in riparian and terra-firme forests differed significantly in abundance, species richness and composition. We also evaluated whether species richness and abundance of bees vary with the size of the forest fragment. Male bees were attracted using odoriferous baits and collected with entomological nets in 10 forest fragments. There was no significant difference between riparian and terra-firme fragments in species abundance, richness and composition, but there was a positive correlation between fragment size and species richness and abundance. Our results suggest that, in an urban landscape, the remaining riparian and terra-firme forest fragments still could maintain 62.7% of the orchid bee species known to occur in the region, reinforcing the conservation value of these forest remnants. Our findings indicate that these fragments provide a potentially important habitat for the maintenance of local bee populations in the landscape.


Webbia ◽  
2020 ◽  
Vol 75 (2) ◽  
pp. 243-250
Author(s):  
Isau Huamantupa-Chuquimaco ◽  
Haroldo C. De Lima ◽  
Domingos B.O.S. Cardoso

The new species Tachigali inca is described and illustrated. It grows in lowland ‘terra firme’ forest of Amazonian Brazil, in the sub-Andean Amazon region of Peru, and in northeastern Bolivia. The species differs markedly from its most closely related species (T. amarumayu, T. prancei and T. setifera, all belonging to the “setifera group”), by the large cylindrical domatia on the leaf rachis, and by the brown-orange pulverulent indumentum on the abaxial surface of the leaflets and the young twigs; on older branches the indumentum becomes darker, degrades and then breaks off. It also differs by its linear petals with the upper half densely tomentose, the hairs forming small tufts.


Author(s):  
Moses Mulwa ◽  
Mike Teucher ◽  
Werner Ulrich ◽  
Jan Christian Habel

AbstractTropical forests suffer severe habitat destruction. Thus, tropical forests frequently consist today of only a few small remnants that are often embedded within a matrix of agricultural fields and tree plantations. Forest specialist species have experienced severe population declines under these circumstances. We studied bird communities based on census plots set up in a near-natural forest block, as well as degraded forest patches, tree plantations, and agricultural fields, across the Taita Hills in southern Kenya. We classified each bird species according its ecology and behavior. We quantified the land cover and landscape configuration around each census plot. Typical forest species were mainly observed in the near-natural forest block, and to a lower extent in degraded forest patches. Plantations were almost devoid of birds. Bird communities of small forest fragments were more similar to that of agricultural land than the near-natural forest block. Most frugivorous, insectivorous and nectarivorous birds occurred in forest habitats, while granivorous bird species dominated the bird communities of agricultural land. The surrounding landscape had a marginal impact on bird species composition at local sites. Our study showed that the preservation of near-natural cloud forest, including small forest patches, is essential for the conservation of forest-dependent species, and that plantations do not serve as surrogate habitats.


Mycorrhiza ◽  
2013 ◽  
Vol 24 (1) ◽  
pp. 21-32 ◽  
Author(s):  
Rejane de Oliveira Freitas ◽  
Erika Buscardo ◽  
Laszlo Nagy ◽  
Alex Bruno dos Santos Maciel ◽  
Rosilaine Carrenho ◽  
...  

Zootaxa ◽  
2021 ◽  
Vol 5047 (5) ◽  
pp. 531-546
Author(s):  
GIOVANNI A. CHAVES-PORTILLA ◽  
ERIKA NATHALIA SALAZAR ◽  
JOSÉ GIL-ACERO ◽  
ADRIANA DORADO-CORREA ◽  
ROBERTO MÁRQUEZ ◽  
...  

A new species of Andinobates (Dendrobatidae) is described from the East Andes of Colombia, just 37 km away from the Colombian capital, Bogotá. Andinobates supata sp. nov., represents the second known species of yellow Andinobates, and can be distinguished from the other, Andinobates tolimensis, by an unique combination of ventral and dorsal color patterns. Our phylogenetic analyses, based on ≈ 1120 bp from two mitochondrial markers (16S rRNA and cytochrome b) showed that this new taxon is sister to a clade formed by A. cassidyhornae, A. bombetes, A. opisthomelas, A. tolimensis and A. virolinensis. The new species appears to be restricted to a handful of small forest fragments (<10 ha) distributed in no more than 5 km2, between 1800–2000 m elevation, where the human activity is high. In addition, more than 90% of the original forest has been logged at the type locality, and its watersheds receive considerable agrochemical discharges. Altogether, the evidence suggests that this new species should be listed as Critically Endangered and should receive immediate attention regarding basic research and urgent conservation measures.  


2014 ◽  
Vol 86 (3) ◽  
pp. 1207-1220 ◽  
Author(s):  
GUILHERME S. TOLEDO-LIMA ◽  
PHOEVE MACARIO ◽  
RACHEL M. DE LYRA-NEVES ◽  
BRUNO P. TEIXEIRA ◽  
LUIZ A.F. DE LIMA ◽  
...  

In northeastern Brazil, the reduction of the natural forest cover to a series of small, isolated fragments has had negative consequences for the local avian fauna, in particular, a loss of the more specialized species, while the populations of some generalists have tended to increase. The present study focuses on the composition and trophic groups of a bird community on a farm in the northeastern Brazilian state of Alagoas. Monthly surveys were conducted between November 2008 and October 2009, based on mist-netting and systematic observations. Overall, 112 species were recorded, of which 76 were associated with the two forest fragments surveyed, while all the others were observed exclusively in the surrounding matrix of pasture and orchards. The bird community presented a predominance of insectivorous species, followed by omnivores. However, specialized trunk-creeping and understory insectivores accounted for only around 15% of the species in this feeding category. The reduced diversity of other guilds and species with more specialized diets, and the complete absence of sensitive species such as large parrots and raptors, reflects the severe fragmentation and degradation of the local forests, which has greatly reduced the availability of dietary resources and breeding sites.


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.


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