scholarly journals Effects of proximity to urban areas on a riparian bird community in remnant Atlantic Forest in southeastern Brazil

Author(s):  
Ana Cecília de Paula Lourenço ◽  
Maria Cecília Barbosa de Toledo

   The goal of this study was to evaluate the effect of urban activities on the structure and composition of a bird community in riparian forests in the state of São Paulo, Brazil. The study was carried out in seven areas of remnant riparian forest where fixed points have been established to sample bird species. Richness, diversity, abundance, frequency and trophic groups were used as metrics of the bird community. At each point measurements were taken for: (1) habitat characteristics: average height of trees, number of trees above 2m, number of shrubs <2m and the percentage of canopy opening; (2) neighborhood characteristics: closest distance from open areas, highways, urban areas, river and floodplain to the point of observation. The observations resulted in 88 species of birds belonging to 34 families. The most representative families were Tyrannidae, Thraupidae and Picidae. The most predominant trophic groups were insectivorous (54%), omnivorous (11.5%) and frugivorous (10.3%). The results obtained showed that the number of trees explained the variation in abundance, while the mean height of the trees explained variations in richness and frequency. Overall, the bird community was negatively affected by proximity of urban areas and highways. In conclusion, the community of birds in the riparian forest may be affected by the loss of trees above 2m and by urbanization, leading mainly to the replacement of species belonging to specialist trophic groups by generalist species and those more adjusted to human presence.

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.


2017 ◽  
Vol 17 (1) ◽  
pp. 36-41
Author(s):  
Namkhaidorj Sainbileg ◽  
Wang Tong ◽  
Yang Fan ◽  
Yang Guisheng

Species diversity and composition of bird community at South Lake Wetland Park in Hohhot city were investigated from October 2013 to September 2014. In total,64 bird species belonging to 33 families and 14 orders were recorded. There are 36 summer migrant species, 15 resident species, 11 traveling species and 2 winter migrant species found. The habitats of birds were grouped into four types (wetland, woodland, grassland and residential area) according to topography and vegetation types in the survey area.Shannon-Weiner Diversity Index (H`) was 2.9450 in wetland area and 1.0768 in grassland area the highest and the lowest values, respectively. The evenness of bird species was 0.4058 lowest in woodland and 0.7581 highest in residential area. The dominance index of bird species was 0.0733 lowest in the wetland and 0.4319 highest in the woodland, respectively. This paper analyzed the relationship between the main dominant bird species and their habitat characteristics,explained the main reasons for the increased bird species number.


2018 ◽  
Vol 18 (2) ◽  
Author(s):  
Alex Augusto de Abreu Bovo ◽  
Marcelo Magioli ◽  
Alexandre Reis Percequillo ◽  
Cecilia Kruszynski ◽  
Vinicius Alberici ◽  
...  

Abstract: Human-modified landscapes (HMLs) are composed by small, isolated and defaunated forest fragments, which are surrounded by agricultural and urban areas. Information on species that thrives in these HMLs is essential to direct conservation strategies in local and regional scales. Since HMLs are dominant in the Atlantic Forest, we aimed to assess the mammalian diversity in a HML in southeastern Brazil and to propose conservation strategies. We collected data of terrestrial (small-, medium- and large-sized) and volant mammals in three small forest fragments (10, 14 and 26 ha) and adjacent areas, between 2003 and 2016, using complementary methods: active search, camera trapping, live-traps, mist nets and occasional records (i.e., roadkills). In addition, we used secondary data to complement our species list. We recorded 35 native mammal species (6 small-sized, 16 medium- and large-sized, and 13 bats) and seven exotic species in the HML. The recorded mammal assemblage (non-volant and volant), although mainly composed of common and generalist species, includes three medium- and large-sized species nationally threatened (Leopardus guttulus, Puma concolor and Puma yagouaroundi) and two data deficient species (Galictis cuja and Histiotus velatus), highlighting the importance of this HML for the maintenance and conservation of mammal populations. Despite highly impacted by anthropogenic disturbances, the study area harbors a significant richness of medium- and large-sized mammals, being an important biodiversity refuge in the region. However, this biodiversity is threatened by the low quality of the habitats, roadkills and abundant populations of domestic cats and dogs. Therefore, we stress the need of conservation strategies focusing on the medium- and large-sized mammals as an umbrella group, which could benefit all biodiversity in the landscape. We recommend actions that promotes biological restoration, aiming to increase structural composition and connectivity of the forest fragments, reducing roadkills and controlling the domestic cats and dogs' populations, in order to maintain and improve the diversity of mammals in long-term.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Bertille Mohring ◽  
François Brischoux ◽  
Frédéric Angelier

Abstract Background Land-use change is one of the main drivers of the global erosion of biodiversity. In that context, it is crucial to understand how landscape characteristics drive the presence of rare endangered species. Nevertheless, it is also important to study common species in multiple habitats, because they represent a large proportion of biodiversity and are essential to maintain ecological functions. Interestingly, some habitats, as farmlands with permanent crops (e.g. vineyards), have been overlooked in the literature. Methods In this study, we investigated the distribution of a widespread and common bird species, the Common Blackbird (Turdus merula), within and between the three main habitats of our study area (rural Western France). We specifically focused on (1) woodlands, (2) farmlands with a high vineyard coverage, and (3) moderately urbanized areas. Specifically, we aimed to assess the beneficial and detrimental effects of these habitats and their fine-scale composition on the presence of a common bird species, relying on a survey by point counts (nearly 100 locations). We studied the effects of habitats and gradients of fine-scale habitat composition on blackbird presence using logistic regression analyses. Results Blackbirds were present in all studied habitats. However, their presence varied between habitats, being lower in vineyards than in woodlands and cities. In woodlands and cities, fine-scale analyses did not reveal any component driving the species’ presence. However, we found that shrub and tree vegetation cover had a significant positive effect on blackbird presence in vineyards. Conclusions Our results are in agreement with the definition of a generalist species. Interestingly, species distribution varied between habitats. The high presence of blackbirds in urban areas suggests that medium-sized cities, despite their artificialization, do not constrain the settlement of this former forest specialist and that green spaces may allow blackbirds to thrive in medium-sized cities. On the contrary, we found an impoverished presence of blackbirds in vineyards and a positive effect of vegetation on their presence in these landscapes. This suggests that permanent crops, and more generally farmlands, may impose important constraints to common species. Future studies should examine how to enhance biodiversity through agricultural management policies, especially in vineyards.


Land ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 153
Author(s):  
Lauren Hepburn ◽  
Adam C. Smith ◽  
John Zelenski ◽  
Lenore Fahrig

There is growing evidence that exposure to nature increases human well-being, including in urban areas. However, relatively few studies have linked subjective satisfaction to objective features of the environment. In this study we explore the links among objective environmental features (tree cover, water, and bird diversity) and subjective judgements of satisfaction. We surveyed residents of Ottawa, Canada (n = 1035) about their satisfaction with their local neighbourhoods. We then compared the survey responses to measures of nature near their homes, including bird diversity (number of bird species), tree canopy cover, and distance to water. After controlling for effects of income and subjective happiness, residents’ neighbourhood satisfaction was positively related to the number of bird species nearby, even before participants were prompted to consider nature. Residents’ appreciation of their local neigbourhood relative to others also increased with tree canopy cover and nearness to water. Unsolicited comments from participants following the survey indicated that while residents consciously appreciate trees and water, the relationship between bird diversity and neighbourhood satisfaction appears to be unconscious; very few of the participants mentioned birds. Based on these results, we speculate that a diverse local bird community may provoke feelings of satisfaction through their presence, activity, and songs. Our results create a compelling argument for city planners and individual residents to maintain bird-friendly spaces in urban areas.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Lucas M. Leveau

Abstract Background The analysis of bird community assembly rules is fundamental to understand which mechanisms determine the composition of bird species in urban areas. However, the long-term variation of community assembly rules has not been analyzed yet. The objectives of this study are (1) to analyze the variation of community assembly rules along rural-urban gradients of three cities in central Argentina and (2) to compare the patterns of community assembly between two periods separated by 6 years. Bird surveys were performed along transects in urban, suburban, and rural habitats during 2011 and 2017. Departures from null models that took into account differences in species richness (standardized effect size, SES) were calculated for functional and phylogenetic diversities. Results A total of 57 species were recorded. Bird species richness was higher in suburban than in urban and rural habitats. SES of functional diversity increased over the years and was significantly lower in urban habitats than in rural habitats, showing a pattern of functional clustering in the most urbanized areas and functional randomness in rural ones. Phylogenetic diversity was higher in both suburban and urban habitats than rural ones, and the phylogenetic clustering in rural bird assemblages changed to randomness in suburban and urban habitats. Conclusions Bird communities in urban habitats were phylogenetically random and functionally clustered, evidencing environmental filtering by urbanization. In contrast, bird communities in rural areas tended to be phylogenetically clustered, evidencing that certain clades are adapted to rural areas. The processes structuring bird communities along rural-urban gradients were consistent between the 2 years compared.


2002 ◽  
Vol 32 (10) ◽  
pp. 1784-1800 ◽  
Author(s):  
Susan J Hannon ◽  
Cynthia A Paszkowski ◽  
Stan Boutin ◽  
Jordan DeGroot ◽  
S Ellen Macdonald ◽  
...  

Forested buffer strips are left along water bodies after forest harvesting to protect water quality and fish stocks, but little is known about their utility as reserves for forest species in managed landscapes. We report on changes in terrestrial vertebrate communities from pre- to post-harvest in experimentally created buffer strips (20, 100, 200, and 800 m wide) in a boreal mixedwood forest in Alberta, Canada. We trapped anuran amphibians and small mammals and spot-mapped bird territories around 12 lakes (4 treatment levels, 3 replicates) before and after harvesting. Changes in small mammal or amphibian abundance were not detected for any treatment relative to controls; however, these species are habitat generalists that used and even bred in clearcuts. Total bird abundance did not change after harvesting, with the exception of crowding in 20-m buffers 1 year post-harvest. Species composition did not change for amphibians and small mammals after harvest, but forest-dependent bird species declined as buffer width narrowed from 200 to 100 m and narrower. We concluded that 20–100 m buffers would not serve as reserves for forest songbirds in managed landscapes, but that 200 m wide strips conserved the pre-harvest passerine bird community, at least up to 3 years post-harvest.


2017 ◽  
Vol 17 (4) ◽  
Author(s):  
Vagner Cavarzere ◽  
Luis Fabio Silveira ◽  
Vinicius Rodrigues Tonetti ◽  
Pedro Develey ◽  
Flávio Kulaif Ubaid ◽  
...  

Abstract Ipanema National Forest, southeastern Brazil, once contained 340 bird species. Forest cover suffered for centuries from log exploitation and, as a result, most of the remaining forests are now an impoverished subset of the original vegetation. We show how the bird community changed over time by comparing historical and recent records. Currently, 228 species can be recorded, for a compilation of 410 species, of which 359 are documented. Some 89 forest species with historical records failed to be detected in recent surveys. Of the 72 Atlantic Forest or Cerrado endemic species, no more than 29 (40%) are still found. The bird community changed from one which used to be related to coastline rain forests to another, which relates more to drier semideciduous forests of the interior.


2020 ◽  
Vol 144 (11-12) ◽  
pp. 558-558
Author(s):  
Mario Slatki ◽  
Jelena Kralj

The correlation between secondary hole-nesters community characteristics and floristic and structural characteristics of their habitat was studied in riverine forest stands near river Drava in Croatia. Standard point count method was used for bird community sampling and circular plot method for habitat sampling. Sampling was carried out on 66 points. PCA analysis that included 28 independent habitat variables was used, followed by Spearman rank correlation between principal component scores and bird community variables (number of species and number of pairs). Tree basal area was used as an indication of stand maturity and to classify studied points into four forest types (ash, poplar, alder and mixed). Eight secondary hole-nesting species and 14 tree species were recorded. The average forest age was 59.8 ± 20.5 years, with ash and mixed stands being on average older than alder and poplar stands. Shannon-Wiener index of secondary hole-nesters diversity was highest in stands with dominant ash and was increasing with stand maturity. A significant positive correlation was found between number of bird species as well as number of pairs and older stands with lower number of tree species and lower relative number of poplar and alder. It can be concluded that diversity of secondary hole-nesting bird species as well as their abundance is correlated with structural habitat characteristics and that older stands show greater bird biodiversity and abundance.


2017 ◽  
Vol 65 (4) ◽  
pp. 1358 ◽  
Author(s):  
Reginaldo José Donatelli ◽  
Donald P. Eaton ◽  
Guilherme Sementili-Cardoso ◽  
Renata Marques Vianna ◽  
Raphael Whitacker Gerotti ◽  
...  

The Pantanal wetlands represent one of the largest flood plains in the World, with extreme climatic variations between dry and wet seasons. The area shelters a high diversity of habitats, representing the main formations found in this sub-region: grasslands, savannah, forested savannah, riparian forests, bays and salines, and Negro river itself. This habitat variability determines the structure and dynamics of the bird community, because most species are closely related to specific habitats. For this, we studied the abundance of bird species from 2001 to 2004 in a Pantanal area of Fazenda Rio Negro, Aquidauana, Brazil. The abundance was compared among those four consecutive years, seasons (dry and wet), time of the day (morning and afternoon), and also between seven different habitats, in order to determine the variation in distribution patterns and habitats used by birds. For this, we used the linear transect method in each of the seven habitats, and recorded bird abundances to obtain richness. The richness registered in the mosaic of habitats was of 201 species for the savannah, 87 in forested savannah, 116 in the riparian forest, 75 in grasslands, 120 in bays, 92 in the salines and 64 in the Negro river, accounting for 348 species in the Pantanal of Rio Negro. Overall, 98 species of migratory birds were registered. The results highlighted some important issues regarding the total abundance of birds in Nhecolândia: Psittacidae was the most abundant family in the region, with prominence in all environments. Recurvirostridae, a monospecific family, showed expressive abundance due to the dominance of Himantopus mexicanus in the salinas, followed by Ardeidae, Anatidae and Cracidae. Other families with high abundance were Tyrannidae, Columbidae, Thraupidae and Emberizidae, all in predominantly terrestrial environments. Moreover: a) The highest number of specimens was recorded in the morning period and in the dry season, regardless of the habitat; b) there were no differences in abundance in the same habitat along the years, but the abundance was different among habitats. In general, the results indicated that there is a relatively stable bird population in each habitat along the annual cycle, but there were differences in abundance among habitats. Thus, additional studies on food availability in dry and wet seasons should be better explored in the future, either in this region or in other Pantanal regions. This fact could better explain the seasonal dynamics of the richness and abundance of birds in the Pantanal area in general.


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