scholarly journals Ecological Gradients Influencing Waterbird Communities in Black Water Lakes in the Anavilhanas Archipelago, Central Amazonia

2012 ◽  
Vol 2012 ◽  
pp. 1-21 ◽  
Author(s):  
Renato Cintra

For the first time, and in a large spatial scale, the influence of ecological properties on the aquatic bird community of black water lakes in Brazilian Amazonia is evaluated. Bird surveys were conducted in 45 lakes. A total of 3626 individuals in 48 bird species were recorded; of these, 31 are aquatic, and 18 of these are primarily piscivorous. Bird richness and abundance were not significantly related to lake shape and productivity but were influenced by hydrological period (low versus high), water depth, transparency, lake isolation, and habitat richness. Matrices of bird species by lake were subjected to multivariate analyses (NMDS) to evaluate how these parameters influence bird community. The variation in bird species composition was positively correlated to lake depth and isolation and negatively correlated to water transparency and habitat richness. The results indicate that period, lake physical characteristics (depth, water transparency), isolation, and habitat richness are determinants of aquatic bird community composition in the black water lake systems of Amazonia.

2010 ◽  
Vol 70 (2) ◽  
pp. 243-254 ◽  
Author(s):  
LT Manica ◽  
M Telles ◽  
MM Dias

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.


2017 ◽  
Vol 9 (2) ◽  
Author(s):  
Roberto Vargas-Masis ◽  
Lilliana Piedra-Castro ◽  
Juan Bravo-Chacón

Wetlands maintain high biodiversity and provide important habitat for many bird species, but now have strong pressure from anthropogenic activities. Birds in wetlands are important indicators of environmental changes and our goal was to characterize the bird community in the wetlands Palustrine Corral de Piedra as a mechanism for conservation of tropical dry forest of Costa Rica. We used point counts to describe bird richness and abundance in open (lakes and flooded grasslands) and wooded areas. We described habitat use and microhabitats, trophic guilds, biogeographic distribution and status in Costa Rica. We recorded 83 species of resident birds belonging to 36 families, of which 65 are resident species and 18 have some migratory status in Costa Rica. Secondary consumer species of small vertebrates corresponded to 45,8% and primary consumers were 25,3%. The birds mainly used trees for perching but use emergent shrubs, floating vegetation and water. We found a large number of Egrets, Flycatchers and Hawks playing important roles as pollinators, seed dispersers and predator is adding significant value to the ecological dynamics of forests and lakes in the area. Corral de Piedra has special importance as a site for the establishment of migratory birds and large number of resident species of conservation concern. We consider that joint efforts between residents and researchers are an important tool for bird conservation in the region.


Diversity ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 308
Author(s):  
Megersa Tsegaye Debela ◽  
Qingming Wu ◽  
Lu Chen ◽  
Xueying Sun ◽  
Zhuo Xu ◽  
...  

The present study aimed to investigate the structure, composition and diversity of the over-wintering aquatic bird community of Poyang Lake, including Poyang Lake National Nature Reserve (PNNR), Nanji National Nature Reserve (NNNR) and Duchang Provincial Nature Reserve (DPNR), China. After the preliminary survey, birds surveyed from vantage points at each study site between the years 2016 and 2020 in the winter season. A total of 58 bird species belonging to nine orders and 13 families were observed. The study showed variation in effective species numbers (Species richness, Shannon’s diversity and Simpson’s diversity) among the three study sites and the survey years. Nanji National Nature Reserve had the highest avian diversity, whereas Duchang Provincial Nature Reserve had the lowest. Globally threatened bird species, Siberian Crane (critically endangered), Oriental Stork (endangered), found in our study sites. However, the current management practices of the nature reserve and conservation of this globally threatened bird species are inadequate, especially of Duchang Provincial Nature Reserve. Therefore, for long term conservation of birds in these areas, it needs continuing intentional improvement of the sites and awareness creation to the local community.


Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1004
Author(s):  
Anaís Rebeca Prestes Rowedder ◽  
Thiago Orsi Laranjeiras ◽  
Torbjørn Haugaasen ◽  
Benjamin Gilmore ◽  
Mario Cohn-Haft

The annual flooding in the Amazon basin transforms the understory of floodplain forests into an aquatic environment. However, a great number of non-aquatic bird species occupy the understory and midstory of these forests. In general, these birds are thought to be sedentary and territorial, but the way they adapt to this dramatic seasonal transformation has never been described in detail. In this study, we describe avifaunal strategies to cope with seasonal flooding in the lower Purus region, central Amazonia, Brazil. We conducted focal observations of five insectivorous species occupying the lowest forest strata in two types of floodplain forest (black- and whitewater) during the low- and high-water seasons. For each observation, the height of the bird above the substrate (ground or water), its vertical position in the forest, and vegetation density around the bird were noted. All species remained present in the floodplain forests during the two seasons and were not recorded in adjacent unflooded (terra firme) forest. In general, birds migrated vertically to higher forest strata and most species (three of the five) occupied similar vegetation densities independent of water level. Despite the tendency of all species to rise in relative vertical position at high water, there was a reduction in height above substrate for four of the five species, suggesting that their position relative to water was not an important microhabitat element for them. Responses were similar in the two floodplain forest types. It is likely that the decrease in available space during the flood, combined with similar vertical displacement in arthropods, leads to increased prey density for understory insectivorous birds and permits year-round territoriality without major habitat shifts.


1997 ◽  
Vol 75 (2) ◽  
pp. 317-323 ◽  
Author(s):  
Miguel Ângelo Marini

Differences in nesting characteristics among species of a bird community may increase the mean reproductive success of all species by decreasing mean predation levels on nests (the predation/diversity hypothesis). I tested this hypothesis by (i) manipulating nest-type richness using natural translocated nests, and (ii) correlating predation levels on artificial nests with understory bird richness. I translocated abandoned natural nests (158 nests in 1992 and 199 nests in 1993) of five species of passerines to four (in 1992) and five (in 1993) 1.5 km long transects (ravines) in two-species or five-species assemblages. Experiments conducted in hardwood forests of southern Illinois, U.S.A., during two breeding seasons (1992 and 1993) showed significantly higher predation levels in low than high nest richness sites in 1992 and 1993, and in overall predation during both years. Predation levels, however, varied considerably within richness treatments. If high site-to-site variability in nest predation is not due to stochastic noise, nesting traits may be selected in opposite directions and strengths in different parts of a species' habitat or range. The nest predation/diversity hypothesis was supported at the landscape level but not at the local (ravine) level, stressing the importance of predation as a process structuring bird communities at a large spatial scale. The consequences of this high variation in nest-predation levels on populations, communities, and ecological processes should be well understood before conclusions are drawn.


2021 ◽  
Vol 43 ◽  
pp. e56931
Author(s):  
Aloysio Souza de Moura ◽  
Felipe Santana Machado ◽  
Ravi Fernandes Mariano ◽  
Cléber Rodrigo de Souza ◽  
Urica Carolina Lemos Mengez ◽  
...  

Brazil has a high diversity of birds and presents the largest number of threatened bird species in the neotropical region. Even so, there are gaps in the bird knowledge, especially in ecotonal montane regions. Given this panorama, this study aimed to analyse the bird community distribution (richness, composition, and beta diversity between phytophysiognomies) of an ecotonal montane landscape of southeastern Brazil, with the purpose of detecting substitution patterns of bird species on a meso-scale. Using bird data performed during the years 1998 to 2015 in 46 sampling points, we found high bird richness in montane phytophysiognomies along an ecotone between Cerrado and Atlantic Forest hotspots. The composition present species of both domains, with high turnover component. We highlight the field environments and candeais are considered homogeneous and threathened, which would directly affect birds. The present study contributes to future conservation strategies, as it demonstrates ecotonal regions as transition zones and reinforces the need to consider as particular ecological units. These ecotonal regions are key locations for understanding ecological patterns in response to environmental changes or phytophysiognomies. Knowing how partitioning of the composition occurs within an environmental mosaic is essential to understand the limits and distributions of the species and conserve them.


2014 ◽  
Vol 281 (1795) ◽  
pp. 20141742 ◽  
Author(s):  
Sadia E. Ahmed ◽  
Alexander C. Lees ◽  
Nárgila G. Moura ◽  
Toby A. Gardner ◽  
Jos Barlow ◽  
...  

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.


2019 ◽  
Author(s):  
Federico Morelli ◽  
Yanina

ContextThe negative association between elevation and species richness is a well-recognized pattern in macro-ecology. ObjectivesThe aim of this study was to investigate changes in functional evenness of breeding bird communities along an elevation gradient in Europe. MethodsUsing the bird data from the EBCC Atlas of European Breeding Birds we estimated an index of functional evenness which can be assumed as a measure of the potential resilience of communities.ResultsOur findings confirm the existence of a negative association between elevation and bird species richness in all European eco regions. However, we also explored a novel aspect of this relationship, important for conservation: Our findings provide evidence at large spatial scale of a negative association between the functional evenness (potential community resilience) and elevation, independent of the eco region. We also found that the Natura2000 protected areas covers the territory most in need of protection, those characterized by bird communities with low potential resilience, in hilly and mountainous areas.ConclusionsThese results draw attention to European areas occupied by bird communities characterized by a potential lower capacity to respond to strong ecological changes, and, therefore, potentially more exposed to risks for conservation.


Land ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 487
Author(s):  
Lillian Collins ◽  
Grant D. Paton ◽  
Sara A. Gagné

The urbanization of landscapes filters bird communities to favor particular species traits, driven in part by the changes that homeowners make to the amount and quality of habitat in yards. We suggest that an ultimate driver of these proximate mechanisms underlying bird community change with respect to urbanization is the likeability of species traits by urban residents. We hypothesize that bird species likeability, modulated by species traits, influences the degree to which homeowners alter the availability and quality of habitat on their properties and thereby affects species population sizes in urbanized landscapes. We refer to this new hypothesis as the Likeable, therefore Abundant Hypothesis. The Likeable, therefore Abundant Hypothesis predicts that (1) bird species likeability varies with species morphological and behavioral traits, (2) homeowners use trait-based likeability as a motivator to modify habitat availability and quality on their properties, and (3) residential habitat availability and quality influences species populations at landscape scales. We tested the first prediction of the Likeable, therefore Abundant Hypothesis using a survey of 298 undergraduate students at the University of North Carolina at Charlotte who were asked to rank their preferences for 85 forest generalist and edge/open country songbird species grouped according to 10 morphological and behavioral traits. Survey respondents preferred very small, primarily blue or black species that are insectivorous, aerial or bark foragers, residents, and culturally unimportant. On the other hand, respondents disliked large or very large, primarily yellow or orange species that forage on the ground and/or forage by flycatching, are migratory, and are culturally important. If the Likeable, therefore Abundant Hypothesis is true, natural resource managers and planners could capitalize on the high likeability of species that are nevertheless negatively affected by urbanization to convince homeowners and residents to actively manage their properties for species conservation.


Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 150
Author(s):  
Lance Jay Roberts ◽  
Ryan Burnett ◽  
Alissa Fogg

Silvicultural treatments, fire, and insect outbreaks are the primary disturbance events currently affecting forests in the Sierra Nevada Mountains of California, a region where plants and wildlife are highly adapted to a frequent-fire disturbance regime that has been suppressed for decades. Although the effects of both fire and silviculture on wildlife have been studied by many, there are few studies that directly compare their long-term effects on wildlife communities. We conducted avian point counts from 2010 to 2019 at 1987 in situ field survey locations across eight national forests and collected fire and silvicultural treatment data from 1987 to 2016, resulting in a 20-year post-disturbance chronosequence. We evaluated two categories of fire severity in comparison to silvicultural management (largely pre-commercial and commercial thinning treatments) as well as undisturbed locations to model their influences on abundances of 71 breeding bird species. More species (48% of the community) reached peak abundance at moderate-high-severity-fire locations than at low-severity fire (8%), silvicultural management (16%), or undisturbed (13%) locations. Total community abundance was highest in undisturbed dense forests as well as in the first few years after silvicultural management and lowest in the first few years after moderate-high-severity fire, then abundance in all types of disturbed habitats was similar by 10 years after disturbance. Even though the total community abundance was relatively low in moderate-high-severity-fire habitats, species diversity was the highest. Moderate-high-severity fire supported a unique portion of the avian community, while low-severity fire and silvicultural management were relatively similar. We conclude that a significant portion of the bird community in the Sierra Nevada region is dependent on moderate-high-severity fire and thus recommend that a prescribed and managed wildfire program that incorporates a variety of fire effects will best maintain biodiversity in this region.


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