Avian species–area relationships indicate that towns are not different from natural areas

SUMMARYUrban areas host many bird species, and urban species richness can be compared with that in natural areas using species–area relationships (SARs). We used a multimodel selection approach to investigate the influence of area, human population, elevation and climatic variables on species richness of breeding birds from 34 towns and 54 nature reserves in Italy. Using the linearized power function, area was identified as the most important correlate of avian species richness in both urban and natural areas. The SARs did not differ significantly between towns and reserves, although human density had a negative effect on bird richness. These findings underline the possible importance of urban areas in biodiversity conservation, but also stress that human density is a factor reducing species richness. However, species richness alone cannot inform conservation priorities because it does not take into account the different conservation values of species.

Download Full-text

Winter bird abundance, species richness and functional guild composition at Delhi’s ponds: does time of day and wetland extent matter?

Journal of Urban Ecology ◽

10.1093/jue/juab001 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Prakhar Rawal ◽

Swati Kittur ◽

Murali Krishna Chatakonda ◽

K S Gopi Sundar

Keyword(s):

Species Richness ◽

Species Abundance ◽

Bird Species ◽

Time Of Day ◽

Conservation Priorities ◽

Bird Abundance ◽

Functional Guilds ◽

Β Diversity ◽

Functional Guild ◽

Guild Composition

Abstract Urbanisation can limit species persistence and bias composition of functional guilds with serious consequences for ecosystem functioning and conservation planning. Standardised biodiversity surveys are missing at most tropical urban cities where biodiversity levels are high alongside rapidly increasing rates of urbanisation. We explored the utility of time-bound surveys to document winter birds at ponds (wetlands ≤ 5 ha) in Delhi, India at two different times of the day (morning and evening) and in areas with varying extents of wetlands. Systematic surveys at 39 ponds during January–March 2020 yielded an estimated 173 ± 22 bird species (∼37% of Delhi’s birds). The total bird species assemblage at ponds did not vary significantly with time of day, but β-diversity increased marginally with increasing extent of wetlands. Total bird abundance and species richness varied substantially with time of day, with differences apparent across several species rich functional feeding and habitat guilds. Abundance and species richness of some guilds, including species-poor guilds, varied in ponds located in areas with differing extent of wetlands. Reliable and comparable measures of species abundance and species richness (both total and across functional guilds)— metrics commonly used to set research and conservation priorities—in urban habitats can be obtained after appropriately standardising field effort. Such standardised efforts can help underscore the importance of maintaining and improving erstwhile-ignored habitats such as unprotected ponds that are providing refugia to hundreds of bird species in mega-cities like Delhi.

Download Full-text

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

Bird Conservation International ◽

10.1017/s0959270911000207 ◽

2011 ◽

Vol 22 (2) ◽

pp. 155-169 ◽

Cited By ~ 13

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.

Download Full-text

Birds of the Parque Ecológico Lagoa da Fazenda, Sobral, Ceará state, northeastern Brazil

Check List ◽

10.15560/13.1.2037 ◽

2017 ◽

Vol 13 (1) ◽

pp. 2037

Author(s):

Ana Carolina Brasileiro ◽

Frede Lima-Araujo ◽

Jamile Aragão Alcântara ◽

Alano Sousa Martins Pontes ◽

José André Neto ◽

...

Keyword(s):

Species Richness ◽

Urban Expansion ◽

Bird Species ◽

Northeastern Brazil ◽

Urban Park ◽

Native Vegetation ◽

Natural Areas ◽

Local Species Richness ◽

Local Species ◽

Richness Estimators

Natural areas within cities are important as they contribute to maintain biodiversity and the functioning of ecosystems. In Ceará state, inventories of birds in human-impacted areas are still scarce. Here, we inventory bird species and estimate the species richness at Parque Ecológico Lagoa da Fazenda, an urban park in the municipality of Sobral, in northeastern Brazil. We found 82 bird species, of which 16 breed in the area, three are endemics, and three others are introduced. Despite the moderate species richness detected, richness estimators revealed that sampling was sufficient to detect most species. To maintain or even increase local species richness, we suggest the cessation of urban expansion within the park, sewage dumping, and filling of the wetland, as well as further planting of native vegetation.

Download Full-text

Suitability of open digital species records for assessing biodiversity patterns in cities: a case study using avian records

Journal of Urban Ecology ◽

10.1093/jue/juab014 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Marufa Sultana ◽

Ilse Storch

Keyword(s):

Urban Areas ◽

Bird Species ◽

Grid Cell ◽

Digital Data ◽

Linear Regression Models ◽

Biodiversity Patterns ◽

Case Examples ◽

Online Platforms ◽

Bird Richness ◽

Resident Bird

Abstract Openly available species observation records on various online platforms achieve good coverage in urban areas. Thus, such digital data could provide a basis for biodiversity assessments in cities. Here, we investigated suitability of open digital species occurrence data, compared with systematically field surveyed data, in Freiburg, Germany (a Western city) and Dhaka, Bangladesh (a global-South city). We focused on resident bird species richness as an indicator of local biodiversity. We collected avian records for urban areas from ‘ornitho.de’ in Freiburg and ‘gbif.org’ in Dhaka. Additionally, we conducted point count surveys at several urban locations in both cities. Using these records, we prepared three grid (cell size 250 m × 250 m) based datasets—open digital dataset (i.e. records compiled from well-surveyed grid cells), field surveyed dataset (i.e. records of systematic bird surveys) and combined dataset (i.e. digital data and field data combined). We compared the relationship of resident bird richness with different habitat factors by applying linear regression models, separately using each of the three datasets. We assessed suitability of data from online platforms by comparing the variables retained after model selection based on digital data versus field surveyed data. We found that field surveyed data and combined data did not alter general understanding of the key driving factors of bird richness patterns we obtained from open digital data. This held for both case examples, Freiburg vs. Dhaka, respectively. This suggests that open digital data from well-surveyed urban locations can provide a suitable basis to assess drivers of biodiversity patterns within cities.

Download Full-text

Species richness and biodiversity conservation priorities in British Columbia, Canada

Canadian Journal of Zoology ◽

10.1139/z05-172 ◽

2006 ◽

Vol 84 (1) ◽

pp. 20-31 ◽

Cited By ~ 15

Author(s):

Kathryn E Freemark ◽

Mark Meyers ◽

Denis White ◽

Leanna D Warman ◽

A Ross Kiester ◽

...

Keyword(s):

At Risk ◽

British Columbia ◽

Species Richness ◽

Bird Species ◽

Species Group ◽

Programming Algorithm ◽

Conservation Priorities ◽

Species At Risk ◽

Distribution Ranges ◽

Species Groups

Patterns in the geographic distribution of seven species groups were used to identify important areas for conservation in British Columbia, Canada. Potential priority sites for conservation were determined using an integer programming algorithm that maximized the number of species represented in the minimum number of sites. Sweep analyses were used to determine how well the set of priority sites identified for each species group represented the other species groups. Although areas of highest species richness were different for each species group, they all included sites in the southern interior of British Columbia, where there is limited protection. Furthermore, less than 13% of the distribution ranges for 23 of 25 bird species of special conservation concern were located within existing protected areas. Species at risk of extinction were poorly represented (26%–42%) in priority sets of sites selected for amphibians, reptiles, birds, and mammals, since these sites were generally scattered throughout the province. However, priority sites for species at risk represented 72%–91% of the species in other groups. Therefore, conservation activities in sites identified for such species have the potential to benefit many other species. These sites could be investigated in more detail to augment existing conservation and protection efforts in British Columbia.

Download Full-text

Human population density and tenebrionid richness covary in Mediterranean islands

Web Ecology ◽

10.5194/we-16-63-2016 ◽

2016 ◽

Vol 16 (1) ◽

pp. 63-65

Author(s):

Simone Fattorini ◽

Giovanni Strona

Keyword(s):

Species Richness ◽

Population Density ◽

Human Population ◽

Intermediate Disturbance Hypothesis ◽

Mediterranean Islands ◽

Environmental Diversity ◽

Human Population Density ◽

Species Area ◽

The Individual ◽

Human Density

Abstract. Human population growth is expected to drive several species to local extinction. Yet, an unexpected high biodiversity can be found even in densely populated areas. Although a positive correlation between human density and biodiversity can be explained by the intermediate disturbance hypothesis, an alternative possible explanation may come from the tendency of human settlements to be located in sites whose environmental conditions are particularly favourable also for many other animal species. To investigate this hypothesis, we studied the relationships between human population density and species richness of native tenebrionid beetles in small Italian islands. We used partial regression analysis to assess the individual contribution of island area (to account for the species–area relationship), elevation (used as a proxy of environmental diversity), and human density to species richness. We found that tenebrionid diversity increased with human population density even after controlling for area and elevation. This may suggest that islands that were (and are) more hospitable to humans are also those which can be more favourable for tenebrionids.

Download Full-text

Consistency in bird community assembly over medium-term along rural-urban gradients in Argentina

Ecological Processes ◽

10.1186/s13717-021-00302-8 ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Lucas M. Leveau

Keyword(s):

Species Richness ◽

Community Assembly ◽

Rural Areas ◽

Urban Areas ◽

Environmental Filtering ◽

Bird Species ◽

Bird Community ◽

Bird Communities ◽

Assembly Rules ◽

Urban Habitats

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.

Download Full-text

Seasonal changes in avian communities living in an extensively used farmland of Western Poland

European Journal of Ecology ◽

10.1515/eje-2016-0012 ◽

2016 ◽

Vol 2 (2) ◽

pp. 9-18 ◽

Cited By ~ 3

Author(s):

Zbigniew Kwieciński ◽

Federico Morelli ◽

Marcin Antczak ◽

Martin Hromada ◽

Paweł Szymański ◽

...

Keyword(s):

Species Richness ◽

Protected Areas ◽

Seasonal Changes ◽

Bird Species ◽

Bird Communities ◽

Negative Trend ◽

Avian Communities ◽

Farmland Birds ◽

Bird Species Richness ◽

Bird Richness

Abstract To study the seasonal changes in avian communities, we collected data in an extensively used farmland in Western Poland during 2006-2013. Generalized additive mixed models were used in order to study the effects of seasonality and protected areas on the overall bird species richness. A similarity percentage analysis was also conducted in order to identify the species that contribute most strongly to dissimilarity among each bird according to the phenological season. Furthermore, the differences in bird communities were investigated applying the decomposition of the species richness in season, trend, and remainder components. Each season showed significant differences in bird species richness (seasonality effect). The effect of the protected areas was slightly positive on the overall species richness for all seasons. However, an overall negative trend was detected for the entire period of eight years. The bird community composition was different among seasons, showing differences in terms of dominant species. Greater differences were found between breeding and wintering seasons, in particular, the spatial pattern of sites with higher bird richness (hotspots) were different between breeding and wintering seasons. Our findings showed a negative trend in bird species richness verified in the Polish farmlands from 2006. This result mirrors the same negative trend already highlighted for Western Europe. The role of protected areas, even if slightly positive, was not enough to mitigate this decline process. Therefore, to effectively protect farmland birds, it is necessary to also consider inter-seasons variation, and for this, we suggest the use of medium-term temporal studies on bird communities’ trends.

Download Full-text

USE OF RESTORATION PLANTINGS TO ENHANCE BIRD SEED DISPERSAL AT THE ROADSIDE: FAILURES AND PROSPECTS

Journal of Environmental Engineering and Landscape Management ◽

10.3846/16486897.2015.1079529 ◽

2015 ◽

Vol 23 (4) ◽

pp. 302-311 ◽

Cited By ~ 5

Author(s):

Rocío de TORRE ◽

María Dolores JIMÉNEZ ◽

Álvaro RAMÍREZ ◽

Ignacio MOLA ◽

Miguel A. CASADO ◽

...

Keyword(s):

Species Richness ◽

Seed Dispersal ◽

Agricultural Landscape ◽

Bird Species ◽

Ecological Processes ◽

Frugivorous Birds ◽

Bird Droppings ◽

Bird Richness ◽

Species Richness And Abundance

Plantings are commonly used in roadside reclamation for ornamental purposes and for increasing slope stability and road safety. However, the role of these plantings in restoring ecological processes, such as seed dispersal, has received little attention. We carried out a study to assess the potential role of plantings on roadside embankments to attract frugivorous birds and to enhance seed dispersal mediated by birds from the surrounding landscape. We examined: (1) bird species richness and abundance; (2) patterns of avian spatial distribution within embankments and (3) seed dispersal mediated by birds. Bird richness and abundance did not differ between embankments with and without plantings. However, birds were not distributed randomly within embankments, with levels of species richness and abundance for facultative frugivorous between 4.8–8 times higher in areas closer to plantings. An analysis of bird droppings showed that birds only dispersed seeds of the planted species since no seeds of woody plants from matrices were detected. These results suggest that plantings acted as selective bird attractors, providing food and perches for frugivorous species. Nevertheless, the scarcity of seed-dispersing birds in the surrounding agricultural landscape prevented plantings from enhancing seed dispersal and connectivity to adjacent habitat.

Download Full-text

Supplementary feeding restructures urban bird communities

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1501489112 ◽

2015 ◽

Vol 112 (20) ◽

pp. E2648-E2657 ◽

Cited By ~ 80

Author(s):

Josie A. Galbraith ◽

Jacqueline R. Beggs ◽

Darryl N. Jones ◽

Margaret C. Stanley

Keyword(s):

Urban Areas ◽

Bird Species ◽

Passer Domesticus ◽

Bird Communities ◽

Supplementary Feeding ◽

Avian Community ◽

Feeding Regime ◽

Negative Effect ◽

Primary Driver ◽

Experimental Feeding

Food availability is a primary driver of avian population regulation. However, few studies have considered the effects of what is essentially a massive supplementary feeding experiment: the practice of wild bird feeding. Bird feeding has been posited as an important factor influencing the structure of bird communities, especially in urban areas, although experimental evidence to support this is almost entirely lacking. We carried out an 18-mo experimental feeding study at 23 residential properties to investigate the effects of bird feeding on local urban avian assemblages. Our feeding regime was based on predominant urban feeding practices in our region. We used monthly bird surveys to compare avian community composition, species richness, and the densities of local species at feeding and nonfeeding properties. Avian community structure diverged at feeding properties and five of the commonest garden bird species were affected by the experimental feeding regime. Introduced birds particularly benefitted, with dramatic increases observed in the abundances of house sparrow (Passer domesticus) and spotted dove (Streptopelia chinensis) in particular. We also found evidence of a negative effect on the abundance of a native insectivore, the grey warbler (Gerygone igata). Almost all of the observed changes did not persist once feeding had ceased. Our study directly demonstrates that the human pastime of bird feeding substantially contributes to the structure of avian community in urban areas, potentially altering the balance between native and introduced species.

Download Full-text