scholarly journals Weak Effects of Owned Outdoor Cat Density on Urban Bird Richness and Abundance

Land ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 507
Author(s):  
Genevieve C. Perkins ◽  
Amanda E. Martin ◽  
Adam C. Smith ◽  
Lenore Fahrig
Keyword(s):  
Urban Areas ◽  
Bird Species ◽  
Lethal Effect ◽  
Bird Communities ◽  
Domestic Cats ◽  
Urban Birds ◽  
Negative Effects ◽  
Bird Populations ◽  
Bird Richness ◽  
Urban Bird

Domestic cats (Felis catus) are ubiquitous predators of birds in urban areas. In addition to the lethal effect of predation, there can also be sublethal, negative effects of domestic cats on individual birds. These effects have led to the inference that reducing outdoor cat densities would benefit urban bird communities. Here we estimate the likely result of policies/programs designed to reduce densities of owned outdoor cats in urban areas, estimating relationships between bird richness/abundance and cat densities across 58 landscapes in Ottawa, Ontario, Canada. We estimate that we would most likely observe one additional bird species, and 0.003 additional individuals per species, if policies/programs reduced owned outdoor cat densities to zero in an average landscape in Ottawa (with 130.2 cats/km2). However, these effects of cat density on birds were uncertain, with 95% confidence intervals crossing zero. Our findings—in combination with those of previous studies—suggest a need for research to resolve the apparent disconnect between the strong, negative effects of cats on individual urban birds and the weak, uncertain effects of cats on bird populations. Although measures that reduce owned outdoor cat densities are justified based on the precautionary principle, evidence to date does not support prioritizing these measures over those addressing threats that have consistently strong effects on bird populations.

scholarly journals Tolerance to Human Presence, a Comparison between Rural and Urban Birds in Southeastern Brazil

2021 ◽  
Vol 2 (3) ◽  
pp. 1-4
Author(s):  
Maria Cecília Barbosa de Toledo
Keyword(s):  
Rural Areas ◽  
Urban Areas ◽  
Bird Species ◽  
Urban Environments ◽  
Southeastern Brazil ◽  
Special Focus ◽  
Forest Fragments ◽  
Urban Birds ◽  
Human Presence ◽  
Individual Bird

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.

Additive negative effects of Philornis nest parasitism on small and declining Neotropical bird populations

2018 ◽  
Vol 29 (03) ◽  
pp. 339-360 ◽  
Author(s):  
MARIANA BULGARELLA ◽  
MARTÍN A. QUIROGA ◽  
GEORGE E. HEIMPEL
Keyword(s):  
Bird Species ◽  
Field Studies ◽  
Habitat Destruction ◽  
Biological Information ◽  
Mortality Factor ◽  
Healthy Population ◽  
Small Populations ◽  
Negative Effects ◽  
Nest Parasitism ◽  
Bird Populations

SummaryThe declining-population paradigm holds that small populations are particularly vulnerable to anthropogenic influences such as habitat destruction, pollution and species introductions. While the effects of particular stressors, such as parasitism, may be unimportant in a large, healthy population, they can be serious and even devastating in situations characterised by a restricted geographic range, or by fragmented or reduced population sizes. We apply this idea to nest parasitism of threatened Neotropical bird species that exist in small populations, focusing on dipteran nest parasites in the genusPhilornis. We review the literature onPhilornisparasitism exerting negative pressure on bird populations that have become small and isolated due to human actions and present a new case ofPhilornisparasitism of a threatened hummingbird species. Our aim is to raise awareness about the exacerbating effect that nest parasites can have on small and declining bird populations; especially when biological information is scarce. The five reviewed cases involve two species of Darwin’s Finches in the Galápagos Islands attacked by the invasiveP. downsi, two species of hawks on islands in the Caribbean attacked by the nativeP. piciandP. obscura, and the Yellow CardinalGubernatrix cristatain southern South America attacked by an unknownPhilornisspecies. We also present new documentation of parasitism of a threatened hummingbird species in mainland Ecuador by an unidentifiedPhilornisspecies. We recommend more field studies to determine the presence of nest parasites in bird populations worldwide to improve understanding how nest parasites affect bird fitness and population viability and to allow time to act in advance if needed. Parasitism byPhilornismay represent a severe mortality factor in most already threatened bird species, putting them at greater risk of extinction. Therefore, parasitism management should be included in all threatened species recovery plans.

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

2018 ◽  
Vol 45 (4) ◽  
pp. 419-424 ◽  
Author(s):  
SIMONE FATTORINI ◽  
GIULIA LIN ◽  
CRISTINA MANTONI
Keyword(s):  
Species Richness ◽  
Urban Areas ◽  
Bird Species ◽  
Avian Species ◽  
Conservation Priorities ◽  
Natural Areas ◽  
Bird Richness ◽  
Negative Effect ◽  
Species Area ◽  
Human Density

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.

scholarly journals Hobby and business on trading birds: Case study in bird market of Sukahaji, Bandung, West Java and Splendid, Malang, East Java (Indonesia)

2019 ◽  
Vol 20 (5) ◽  
Author(s):  
BUDIAWATI S ISKANDAR ◽  
JOHAN ISKANDAR ◽  
RUHYAT PARTASASMITA
Keyword(s):  
Urban Areas ◽  
Quantitative Methods ◽  
Environmental Changes ◽  
Bird Species ◽  
Development Program ◽  
Economic Benefits ◽  
West Java ◽  
Urban Bird ◽  
The City

Abstract. Iskandar BS, Iskandar J, Partasasmita R. 2019. Hobby and business on trading birds: Case study in bird market of Sukahaji, Bandung, West Java and Splendid, Malang, East Java (Indonesia). Biodiversitas 20: 1316-1332. Bird species have various ecological and socio-economic-cultural functions for the human being. Ecologically, birds have beneficial functions in the ecosystem, such as helping plant pollinators, spreading plant seeds, participating in controlling agricultural pests, and monitoring environmental changes. Meanwhile, bird functions for the social-economic and culture of the community among them are known as sources of protein food, mystical functions, sources of material stories, sources of inspiration to make songs, craft materials, the source of gene pool, and become pets and trade animals. With the rise of the urban population hobby of raising birds and also the development of various bird contest activities in the urban, causing of the bird trade is very widespread in urban areas, such as in bird markets. In some cities in Indonesia, various bird markets have been popularly known for a long time. This study aimed to elucidate species diversity, folk classification, bird populations, bird prices, constraints to bird trade, and the positive and negative effects of bird trade in the urban bird market. The research method used a mixture of qualitative and quantitative methods with the ethnoecological approach. The results of this study showed that from a survey of 60 bird traders in the bird market of Sukahaji, Bandung, and Splendid, Malang, a total of 160 bird species, representing 38 families were documented. Among them, 10 species representing 7 families recorded as protected bird by law in Indonesia, based on recent government regulation of the Minister of Environment and Forestry of Republic of Indonesian No.106/MENLHK/SETJEN/KUM.1/12/2018. A total of 2,950 individuals were recorded in Sukahaji; while in Splendid were recorded 3,558 individuals. Prices of birds that are traded varied greatly depending on the species and characteristics of birds. It has been revealed that bird trade in the bird market has been various economic benefits for many people. However, due to the bird trade in bird markets in the city which has not been properly managed, the sustainability system of the bird trade in the city is very alarming caused of many factors, including decreasing of bird population over time in rural ecosystem as main supply of urban bird trading in the bird markets. Therefore, bird trading in the bird markets must be properly managed based on the sustainable development program concept, namely pro-economic, pro-social, and pro-environment.

Do domestic cats impose an unsustainable harvest on urban bird populations?

2010 ◽  
Vol 143 (1) ◽  
pp. 121-130 ◽  
Author(s):  
Yolanda van Heezik ◽  
Amber Smyth ◽  
Amy Adams ◽  
Joanna Gordon
Keyword(s):  
Domestic Cats ◽  
Bird Populations ◽  
Urban Bird

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

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.

Bird communities and the structure of urban habitats

1979 ◽  
Vol 57 (12) ◽  
pp. 2358-2368 ◽  
Author(s):  
Richard K. Lancaster ◽  
William E. Rees
Keyword(s):  
Species Diversity ◽  
Urban Areas ◽  
Bird Species ◽  
Major Effect ◽  
Bird Communities ◽  
Ecological Niches ◽  
Urban Habitats ◽  
Natural Habitats ◽  
Bird Density ◽  
Bird Species Diversity

We examine relationships between bird communities and habitat structure along a gradient of urban habitats in Vancouver, B.C. Bird species diversity, evenness of species abundances, and numbers of species increase with foliage height diversity and total vegetation as they do in "natural" habitats. Few ecological niches for birds are enhanced by man-made features of the urban environment. Bird species diversity is actually inversely related to the apparent increase in habitat diversity contributed by elements of the built environment. While limited to a few niches, food provided by man has a major effect on density and distribution of birds in urban areas. Therefore, despite declining natural productivity and species diversity, total bird density does not decline across the Vancouver urban gradient. Overall, available habitat and food in highly urbanized environments strongly favour the few cavity-nesting, ground-feeding graminivorous or omnivorous bird species that have already come to dominate.

scholarly journals Breeding Bird Communities in a Naturally Fragemented Forest Ecosystem in Grand Teton National Park

1998 ◽  
Vol 22 ◽  
pp. 37-37
Author(s):  
Gregory Schrott
Keyword(s):  
Habitat Fragmentation ◽  
National Park ◽  
Bird Species ◽  
Bird Communities ◽  
Western North America ◽  
Breeding Bird ◽  
Grand Teton National Park ◽  
Bird Populations ◽  
Natural Processes

This project examined the bird species breeding in the morainal forests on the valley floor in Grand Teton National Park. These forests are very patchily distributed and range in size from less than 1 hectare to over 700 hectares, allowing for a unique opportunity to study the responses of the local bird species to a forest system that has been fragmented for centuries through natural processes. This information can be useful for predicting the potential long-term impacts of human-caused forest fragmentation on bird populations in western North America. Until quite recently very little was known of the tolerances of western forest bird species to habitat fragmentation and this project could represent an important step towards understanding their needs in this regard.

scholarly journals The Potential Role of Drove Roads as Connecting Corridors for Birds between Natura 2000 Sites

Birds ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 314-328
Author(s):  
Juan E. Malo ◽  
Cristina Mata
Keyword(s):  
Green Infrastructure ◽  
Urban Areas ◽  
Forest Cover ◽  
Natura 2000 ◽  
Bird Communities ◽  
Tree Cover ◽  
Stepping Stones ◽  
Natural Habitats ◽  
Bird Abundance ◽  
Bird Richness

Ecological connectivity among protected Natura 2000 sites is a priority for conservation in Europe due to the increasing pressure on biodiversity from human activities and climate change. Drove roads, the traditional paths used to move livestock through the territory, have been proposed as potential ecological corridors due to their large extent, continuous nature and centennial protection from ploughing and urbanization, which allows the persistence of some tree cover and natural habitats in them. Bird communities were sampled during the reproductive season along 19 drove road transects in agrarian landscapes between Natura 2000 sites, all of them around the conurbation of Madrid (Madrid Region, Spain). Bird community nestedness was assessed by NODF computation followed by significance estimation by aleatorization, and factors explaining species richness and bird abundance were analyzed through General Linear Models fitted with environmental variables measured on official vegetation maps and orthophotos. Bird communities in drove roads were significantly nested, showing high predictability in the order of species loss from better preserved sites to those under stronger environmental pressures. Accordingly, Poisson regression showed bird richness to decrease strongly with distance from the closest Natura 2000 site and to increase with forest cover at the landscape and at the drove road scales. Bird abundance increased strongly with distance from urban areas and motorways, and it was slightly higher in areas with more forest cover and in transects with less bare ground. These results, and the higher relevance detected for landscape scale variables (500 m around transects) than for those at the drove road (50 m) scale, show that (i) they can only play a secondary role as habitat for nesting birds but (ii) they may add to the Green Infrastructure strategy as facilitators or stepping stones for bird communities if the surrounding landscape is favorable for them.

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