scholarly journals Effect of habitat heterogeneity on bird assemblages in a grassland-forest ecotone in Brazil

2016 ◽  
Vol 13 (1) ◽  
pp. 8 ◽  
Author(s):  
André De Mendonça Lima ◽  
Solana Meneghel Boschilia ◽  
Jorge Bernardo Silva ◽  
Ronei Baldissera
Keyword(s):  
Bird Species ◽  
Guild Structure ◽  
Plant Structure ◽  
Forest Patches ◽  
Forest Expansion ◽  
Bird Assemblages ◽  
Alpha And Beta Diversity ◽  
Point Counts ◽  
Forest Interior ◽  
Bird Richness

The present study evaluates differences in alpha and beta diversity and guild structure of bird assemblages along the ecotone between grassland and Araucaria forest in Southern Brazil. Birds were sampled by point counts (radius of 25 m) disposed in the grassland, in the grasslandforest edge, and in the forest interior, grouped in three blocks. Grassland presented low bird richness and abundance, and the bird composition and guild structure in grasslands were different from the edge and the forest interior. Grassland showed more granivores, while forest interior presented more omnivores, insectivores and insectivores/ frugivores. Notwithstanding, there was an overlap on the occurrence of some forest bird species in the edge and grassland, evidencing that the grassland plant structure composed of small forest patches and shrubs could facilitate bird movements, which, in turn, could influence forest expansion dynamics over the grassland.

scholarly journals Distributions and Community Composition of Birds in Iraq’s Central Marsh

2017 ◽  
Vol 2017 ◽  
pp. 1-28 ◽  
Author(s):  
Nadheer A. Fazaa ◽  
Jonathon C. Dunn ◽  
Mark J. Whittingham
Keyword(s):  
Cluster Analysis ◽  
Community Composition ◽  
Bird Species ◽  
Bird Assemblages ◽  
Point Counts ◽  
Migrant Birds ◽  
The Government ◽  
Management Recommendations ◽  
First Time ◽  
Southern Iraq

The Central Marsh (CM) in southern Iraq is known to provide important habitats for both resident and migrant birds. The CM has been used extensively by humans, in part due to its high levels of productivity and biodiversity. It was drained in the 1990s by the government and reflooded and restored in 2003. Recent brief surveys of the CM from 2005 to 2010 recorded 94 bird species. Our study combined transects and point counts in detailed monthly surveys from October 2013 to June 2014 in the CM. We found a total of 125 bird species in the CM across all surveys, with 31 species recorded for the first time in the CM and 11 species categorised as red listed by the IUCN. Fourteen species were confirmed breeding in the CM. Cluster analysis using NMDS ordination showed that the study area can be divided into three main clusters of bird assemblages which are presented here. We provide management recommendations based on our findings.

scholarly journals Using birds to set conservation priorities for Pantanal wetland forests, Brazil

2011 ◽  
Vol 22 (2) ◽  
pp. 155-169 ◽  
Author(s):  
JOÃO BATISTA DE PINHO ◽  
MIGUEL ÂNGELO MARINI
Keyword(s):  
Bird Species ◽  
Dry Forest ◽  
Evergreen Forest ◽  
Conservation Priorities ◽  
Forest Types ◽  
Dry Forests ◽  
Point Counts ◽  
Evergreen Forests ◽  
Local Species Richness ◽  
Bird Richness

SummaryThe Pantanal of Brazil, one of the largest wetlands in the world, is suffering severe threats, such as forest and grassland clearance on the surrounding plateau, conversion of forests and savannas for cattle ranching and effects of large development projects. We used richness, abundance and composition of bird species in four forest types to propose conservation priorities for the northern Pantanal. Birds from 11 sites (a total of 41 points) were sampled through point counts and mist-netting. In total 215 species were recorded in the forests. Two evergreen forest types (cambarazal and landi) had higher estimates of bird richness and abundance than two dry forest types (carvoeiro and cordilheira). The evergreen forests also had more species exclusive to them and were more similar to each other than the dry forests. Selection of forests to be conserved in the northern Pantanal should give priority to evergreen forests and secondarily to dry forests. Cambarazal should be the first forests to be conserved. If the Pantanal inundation cycle is altered by the construction of hydroelectric dams or the Paraguay-Paraná waterway, cambarazal and landi may no longer become flooded, decreasing local species richness. Before our recommendations are considered for conservation and management decisions, more studies on other groups of organisms should also be taken into consideration, and similar studies should be conducted in other regions of the Pantanal. Conservation of Pantanal forest birds depends on a deeper understanding of their use of several habitats, stronger protection of the forests with higher diversity, and public policies that guarantee the long term maintenance of natural flooding cycles.

scholarly journals Variation in hierarchical guild structure between two bird assemblages of a wetland in the Mexican Pacific

2017 ◽  
Vol 65 (4) ◽  
pp. 1540 ◽  
Author(s):  
Mateo Donald Ruiz Bruce Taylor ◽  
José Luis Rangel Salazar ◽  
Paula Enríquez ◽  
Jorge L. León-Cortés ◽  
Carlos García-Estrada
Keyword(s):  
Habitat Preferences ◽  
Species Abundance ◽  
Bird Species ◽  
Ecological Groups ◽  
Trophic Guilds ◽  
Guild Structure ◽  
Habitat Types ◽  
Species Identity ◽  
Mexican Pacific ◽  
Bird Assemblages

Neotropical wetlands comprise contrasting habitats with highly diverse avifauna, including herbivores, insectivores and carnivores, of both terrestrial and aquatic species. Therefore, comparisons between wetland bird assemblages based only on species identity may disregard turnover within ecological groups, and eclipse important variations between habitat types. We studied bird assemblages from mangrove and estuary habitat types from a coastal lagoon system in Oaxaca, Mexico. For this, we used 640 point counts to obtain data on bird species using those habitats between October 2009 and May 2012. We ascertained guild structure by classifying 139 species in a scalar hierarchy of two-levels: 17 key-resource guilds nested within seven trophic guilds. To evaluate variation in guild structure between habitat types, we contrasted richness and diversity across trophic guilds and tested for variation in abundance within key-resource guilds. We exposed a tendency of greater diversity within terrestrial guilds in mangrove and within aquatic guilds at the estuary. However, these differences were compensatory and neither richness nor diversity varied between habitat types in comparisons across the sets of trophic guilds. Parallel analyses at two hierarchical levels supported the theoretical prediction of greater change at lower levels. Herpetofauna, wood invertebrates, aquatic invertebrates and seeds emerged as dietary components that may explain the distribution of abundance in key-resource guilds. Although the guilds from mangrove and estuary produced comparable sets of richness and diversity values, the actual identity of guilds with high values varied between habitats. On the other hand, species abundance comparisons within guilds pinpointed specific associations with habitat types and this method represents a suitable strategy for identifying habitat preferences in complex wetland bird assemblages.

scholarly journals Acoustic indices applied to biodiversity monitoring in a Costa Rica dry tropical forest

2018 ◽  
Vol 2 (1) ◽  
pp. 1-1 ◽  
Author(s):  
Mónica I. Retamosa Izaguirre ◽  
Oscar Ramírez-Alán
Keyword(s):  
Tropical Forests ◽  
Diversity Index ◽  
Bird Species ◽  
Canopy Cover ◽  
Lower Percentage ◽  
Bird Diversity ◽  
Biodiversity Monitoring ◽  
Bird Abundance ◽  
Point Counts ◽  
Bird Richness

Standardized methods for biodiversity monitoring are needed to evaluate conservation efforts. Acoustic indices are used in biodiversity assessments, but need to be compared to traditional wildlife methods. This work was conducted in the Santa Rosa National Park between June and November, 2015. We installed recorders and conducted bird point counts in twelve sampling sites. We compared acoustic indices (Acoustic Evenness Index [AEI], Acoustic Diversity Index [ADI], Acoustic Complexity Index [ACI], Bioacoustic Index [BIO], Normalized Difference Soundscape Index [NDSI], Total Entropy [TE], Median Amplitude Envelope [MAE], Number of peaks [NP]) with indices from bird point counts (Bird Abundance, Bird Richness, Bird Diversity and Bird Evenness), and discuss the utility of acoustic indices as indicators for biodiversity monitoring in tropical forests. ADI, ACI, BIO and TE presented a similar temporal pattern peaking between 5 am and 6 am; and an additional peak at 5 pm, except for ACI. These patterns were consistent with the daily biological rhythms. AEI, ACI, BIO and Bird Abundance were related to characteristics of younger forests (lower percentage of canopy cover) but NP, ADI, TE, Bird Diversity and Bird Evenness were related to characteristics of older forests (higher percentage of canopy cover and a lower number of patches). ACI was positively correlated to Bird Abundance and NP was positively correlated to Bird Diversity. ACI reflects biological activity, but not necessarily a more diverse bird community in this study area. This might be an indication of a strong acoustic competition, or several highly dominant bird species in younger forests. Furthermore, acoustic communities in tropical forests commonly include insects (cicadas) and frogs, which might affect resulting acoustic indices. A variety of methods are probably needed to thoroughly assess biodiversity. However, a combination of indices such as ACI and NP might be considered to monitor trends in abundance and diversity of birds in dry forests.

scholarly journals Spatial distribution patterns of terrestrial bird assemblages on islands of the Sabana–Camagüey Archipelago, Cuba: evaluating nestedness and co–occurrence patterns

2013 ◽  
Vol 36 (2) ◽  
pp. 195-207
Author(s):  
C. A. Mancina ◽  
◽  
D. Rodriguez Batista ◽  
E. Ruiz Rojas ◽  
◽  
...  
Keyword(s):  
Bird Species ◽  
Distribution Patterns ◽  
Trophic Levels ◽  
Distribution Data ◽  
Random Structure ◽  
Bird Assemblages ◽  
Weighting Factors ◽  
Bird Richness ◽  
Occurrence Pattern ◽  
Occurrence Patterns

Using distribution data of 131 terrestrial bird species on 17 islands of the Archipelago Sabana–Camagüey, Cuba, we tested for non–randomness in presence–absence matrices with respect to co–occurrence and nestedness. We conducted separate analyses for the whole assemblage and sub–matrices according to trophic levels and residence status (breeding and migratory). We also explored the influence of weighting factors such as island area and isolation. The C–occurrence analyses were susceptible to the species subsets and the weighting factors. Unweighted analyses revealed a significant negative co–occurrence pattern for the entire assemblage and for most sub–matrices. The area weighted analyses always indicated strong non–random structure. However, an analysis with intra–guild species pairs showed that most pairs were randomly assembled; very few pairs had a significant segregated pattern. Bird assemblages followed a nested subset structure across islands. Nestedness was strongly correlated with area and unrelated with island isolation. Overall, this study suggests that terrestrial bird assemblages were shaped by extinction processes mediated through area effects rather than interspecific trophic guild competition. Data suggest that conservation of largest islands will guarantee high terrestrial bird richness on the archipelago.

Die Brutvogelfauna eines Nadelwaldes der nördlichen Voralpen nach dem Sturm Lothar

2017 ◽  
Vol 168 (2) ◽  
pp. 59-66
Author(s):  
Pierre Mollet ◽  
René Hardegger ◽  
Res Altwegg ◽  
Pius Korner ◽  
Simon Birrer
Keyword(s):  
Forest Succession ◽  
Coniferous Forest ◽  
Bird Species ◽  
Individual Species ◽  
Mountain Forest ◽  
Breeding Bird ◽  
Point Counts ◽  
Federal Institute ◽  
Central Switzerland ◽  
Bird Fauna

Breeding bird fauna in a coniferous forest in the northern Prealps after storm Lothar In a 70-hectare large coniferous forest located on the northern edge of the Alps in central Switzerland, Canton of Obwalden, at an altitude of 1260 to 1550 metres above sea level, we surveyed the local breeding bird fauna in 2002 and 2013 by means of point counts as well as additional area searches for rare species. In December 1999, hurricane Lothar caused two large windthrow areas and several smaller areas with scattered throws in the survey range. We found a total of 48 breeding bird species, which is a very diverse species composition for a mountain forest. In the eleven years between surveys, a decline in distribution or abundance was recorded for four species, while seven species showed an increase; a further four species showed no change. For the remaining species, the data sets were too small to reliably estimate changes. A comparison with forest structure data provided by the Swiss Federal Institute of Forest, Snow and Landscape Research WSL revealed that for five bird species, the changes in distribution or abundance could be explained at least partially by forest succession. In order to obtain realistic distribution and abundance values in this kind of breeding bird survey, it is essential to collect large enough samples and to consider the detection probability of each individual species using appropriate statistical methods.

scholarly journals Bird communities in a degraded forest biodiversity hotspot of East Africa

2021 ◽  
Author(s):  
Moses Mulwa ◽  
Mike Teucher ◽  
Werner Ulrich ◽  
Jan Christian Habel
Keyword(s):  
Tropical Forests ◽  
Agricultural Land ◽  
Bird Species ◽  
Bird Communities ◽  
Natural Forest ◽  
Tree Plantations ◽  
Agricultural Fields ◽  
Degraded Forest ◽  
Forest Patches ◽  
Small Forest

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.

scholarly journals Can clearcuts increase bird species richness in managed forests?

2008 ◽  
Vol 54 (No. 4) ◽  
pp. 189-193
Author(s):  
M. Żmihorski
Keyword(s):  
Species Richness ◽  
Bird Species ◽  
Bird Communities ◽  
Cumulative Number ◽  
Managed Forests ◽  
Managed Forest ◽  
Bird Species Richness ◽  
Forest Interior ◽  
Transect Counts ◽  
The Difference

Clearcuts are one of the results of forest management. The aim of this study was to assess the effect of clearcuts on bird communities in a managed forest in Western Poland. I applied the method of point transect counts. 20 points were located near clearcuts (less than 100 m from the nearest clearcut) and 25 points in the forest interior. In total, 36 bird species were recorded. On average, I found 9.20 bird species at points located near clearcuts and 6.72 species at points situated in the forest interior, and the difference was significant. The cumulative number of bird species for a given number of sampling points in the vicinity of clearcuts was higher than in the forest interior. The obtained results indicate that in managed, even-aged forests the generation of clearcuts can lead to an increase in local bird species richness.

Modelling bird richness and bird species presence in a boreal forest reserve using airborne laser-scanning and aerial images

Bird Study ◽  
2014 ◽  
Vol 61 (2) ◽  
pp. 204-219 ◽  
Author(s):  
Katrine Eldegard ◽  
John Wirkola Dirksen ◽  
Hans Ole Ørka ◽  
Rune Halvorsen ◽  
Erik Næsset ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Laser Scanning ◽  
Bird Species ◽  
Airborne Laser Scanning ◽  
Aerial Images ◽  
Forest Reserve ◽  
Airborne Laser ◽  
Bird Richness

scholarly journals Bird richness and composition in a Cerrado fragment in the State of São Paulo

2010 ◽  
Vol 70 (2) ◽  
pp. 243-254 ◽  
Author(s):  
LT Manica ◽  
M Telles ◽  
MM Dias
Keyword(s):  
Conservation Status ◽  
Bird Species ◽  
Low Frequency ◽  
Bird Community ◽  
Sao Paulo ◽  
The State ◽  
São Paulo ◽  
Conservation Area ◽  
Tropical Regions ◽  
Bird Richness

Bird species richness is an important measure for monitoring biodiversity changes. We analysed avifauna richness and composition in a 472 ha protected cerrado fragment and surroundings at Fazenda Canchim (RL-CPPSE), São Carlos, in the State of São Paulo (SP). We carried out 95.1 hours of observation (22 visits) at irregular intervals from May 2004 to December 2006. Qualitative surveys were done walking through tracks inside the fragment and on the roads at its edge. We recorded 160 species, six of which were endemic to Cerrado domain, 22 migratory, seven threatened within the State of São Paulo, and two globally threatened. We found 28 species in the cerradão, 110 in the cerrado sensu stricto, 13 in the gallery forest, 26 in the reservoir border, 26 in pasturelands and sugar cane monoculture and 55 in an anthropic area. Most of the species had low frequency of occurrence in all vegetation forms. Insectivores were the major trophic category (46.9%), which is typical in tropical regions, and it is also related to resource availability. Omnivores followed with 19.4%, granivores with 8.8% and frugivores with 7.5%. We conclude that, despite its size and conservation status, our study area has a remarkable bird community and must be considered as a priority conservation area to preserve bird species in Sao Paulo State.

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