Article

Non-uniform bird assemblages in urban environments: the influence of streetscape vegetation

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Abstract

The urban landscape encompasses a broad spectrum of variable environments ranging from remnant patches to highly modified streetscapes. Despite the expansion of urban environments, few studies have examined the influence of urbanization on faunal diversity, particularly in the Southern Hemisphere. In this study, four broad habitat types were recognized in the urban environment, representing a continuum of modification ranging from parks with remnant vegetation to streetscapes dominated by native vegetation and those dominated by exotic vegetation to recently developed streetscapes. Bird censuses were conducted at 36 sites throughout urban Melbourne, with nine sites surveyed in each habitat type. The four habitat types supported significantly different bird communities based on species richness, abundance and composition suggesting that bird assemblages of urban environments are non-uniform. Parks and native streetscapes generally supported fewer introduced species than exotic and recently developed streetscapes. Overall abundance and richness of species were lower in the exotic and recently developed streetscapes than in parks and native streetscapes. Significant differences were also observed in foraging guilds within the four habitat types, with parks having the most foraging guilds and recently developed streetscapes having the fewest. The transition from native to exotic streetscapes saw the progressive loss of insectivorous and nectarivorous species reflecting a reliance by these species on structurally diverse and/or native vegetation for both shelter and food resources. The implementation of effective strategies and incentives which encourage the planting of structurally diverse native vegetation in streetscapes and gardens should be paramount if avian biodiversity is to be retained and enhanced in urban environments. It is also critical to encourage the maintenance of the existing remnant vegetation in the urban environment.

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... La urbanización tiene un impacto en la diversidad de las comunidades de aves, así como en la distribución y abundancia de las especies (Robbins et al. 1989, Chace y Walsh 2006. En estudios de gradientes de urbanización se ha observado una mayor riqueza en sitios poco perturbados (Blair 1996, mientras que para hábitats urbanizados se reporta una menor diversidad con predominio de aves exóticas (White et al. 2005), que, en conjunto con las alteraciones ambientales propias de la urbanización, puede llevar a la extirpación de algunas especies nativas en estos hábitats (Virkkala et al. 1993, Blair 1996. Un área muy urbanizada puede conducir entonces a un cambio en la composición de especies, un incremento en la abundancia de aves exóticas o ligadas a medios urbanos, y una reducción notable en la riqueza de aves. ...
... La menor riqueza observada en el ambiente urbano indica que la mayor urbanización de Bernal, a pesar de ser un asentamiento pequeño, ha reducido la riqueza de especies de aves, como generalmente ocurre en estos ambientes (Chace y Walsh 2006), y como ha sido observado en asentamientos urbanizados mexicanos de tamaño reducido (MacGregor-Fors y Schondube 2012). Esta reducción de especies en el ambiente urbano fue acompañada por una marcada mayor abundancia de las especies exóticas Streptopelia decaocto (tórtola turca), Columba livia, Passer domesticus y Quiscalus mexicanus, como ha sido registrado para este tipo de especies en muchas otras ciudades (Robbins et al. 1989, White et al. 2005, Chace y Walsh 2006. ...
... En este sentido resalta el que las especies exóticas mostraron una alta preferencia por los ambientes alterados rural y urbano, las especies endémicas por los ambientes poco alterados matorral y ribereño, y otras especies residentes y migratorias tuvieron mayores abundancias en el medio rural. El cambio gradual encontrado en la composición de especies también sugiere que las comunidades responden a factores ambientales muy locales, como ha sido observado para la riqueza y la abundancia de aves en diferentes tipos Las especies que marcaron las principales diferencias entre los ambientes fueron especies exóticas ligadas a ambientes urbanizados, como ha sido reportado para P. do mesticus, C. livia y Q. mexicanus; mientras que M. ater, que en los muestreos urbanos lo registramos sólo en las pri meras horas de la mañana, es una especie nativa que muchas veces pernocta en las ciudades pero se alimenta en los campos (Howell y Webb 1995, Wehtje 2003, White et al. 2005. Por otra parte, cuatro especies no exóticas resaltaron para diferenciar la avifauna del ambiente rural: Haemorhous mexicanus, Zenaida asiatica, Columbina inca y Setophaga coronata, las tres primeras son residentes y la última es migratoria, lo cual explica en parte la mayor abundancia de especies residentes y migratorias encontrada en la zona rural. ...
Article
El humano ha alterado la mayoría de los ecosistemas a nivel global. La urbanización es actualmente una de las mayores causas de deterioro de los ecosistemas. En este estudio analizamos la diversidad de aves y su posible asociación con atributos ambientales en cuatro ambientes antrópicos: urbano, rural, ribereño y matorral xerófilo, en una zona semiárida del centro de México. En cada ambiente ubicamos 11 puntos de conteo, que visitamos cuatro veces de diciembre de 2014 a abril de 2015. Aplicamos un análisis multivariado para comparar localidades y factores ambientales. La zona urbana presentó una menor diversidad de aves y el resto de los ambientes no tuvo diferencias en su riqueza de especies. La composición de especies presentó cambios de acuerdo con un gradiente de alteración. La alta diversidad beta muestra la necesidad de realizar acciones de conservación en el conjunto de ambientes, especialmente mantener parches de vegetación en zonas urbanas y rurales, así como conservar los ambientes con menos impacto antrópico. Resalta la importancia del ambiente rural por su riqueza de especies, la mayor abundancia en especies nativas residentes, y la mayor riqueza y abundancia de especies migratorias. Estos resultados apoyan la necesidad de realizar acciones de manejo para integrar ambientes alterados en la conservación de la biodiversidad.
... Street trees (i.e., trees growing along streets) in suburban environments can influence local populations of wildlife, including both exotic and native species (Fernandez-Juricic 2000, Murgui 2007, White et al. 2005. Streetscapes that include trees and other woody vegetation can serve as a functional, intermediary habitat between urban parks and streetscapes with no vegetation (Fernandez-Juricic 2000, Murgui 2007) and can mitigate the negative effects of anthropogenic noise (e.g., vehicle traffic) on avian communities (Pena et al. 2017). ...
... Streetscapes that include trees and other woody vegetation can serve as a functional, intermediary habitat between urban parks and streetscapes with no vegetation (Fernandez-Juricic 2000, Murgui 2007) and can mitigate the negative effects of anthropogenic noise (e.g., vehicle traffic) on avian communities (Pena et al. 2017). In addition, wooded streetscapes might constitute a functional habitat corridor for some bird species, facilitating their movement through the urban matrix and providing small parcels of habitat (Fischer and Lindenmeyer 2002, Sodhi et al. 1999, White et al. 2005. ...
... Several bird species appeared to exhibit clear preferences for one or more of these streetscapes, whereas other species used all of the streetscapes relatively equally. These findings are consistent with studies of streetscapes in cities located on other continents, including Europe (Fernandez-Juricic 2000, Murgui 2007) and Australia (Ikin et al. 2013, White et al. 2005, Young et al. 2007. ...
Article
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Urban areas are highly modified environments that are strongly influenced by a variety of anthropogenic factors. Consequently, these areas contain unique wildlife communities typically dominated by species that are generalist in nature or highly adaptable. We examined the use of five species of exotic treescapes by exotic and native birds in metropolitan areas of Phoenix, Arizona. House Sparrows [Passer domesticus (37%)], European Starlings [Sturnus vulagris (27%)], Mourning Doves [Zenaida macroura (11%)], and Great-tailed Grackles [Quiscalus mexicanus (7%)] were the most frequently observed species during the study. Approximately two-thirds (67%) of the birds observed during the study were exotic species. Avian community composition and diversity associated with these streetscapes varied among the tree species. Growth habits and other characteristics of the trees themselves, in addition to the landscaping components beneath and adjacent to the street trees, influenced bird use of these habitats in this highly urbanized desert environment. Our findings demonstrate that exotic street treescapes might provide some ecological value to urban birds.
... Although street tree plantings sometimes increase road mortality of wildlife species (Orłowski, 2008), they reduced the negative effects of road noise exposure on animals (De Castro Pena et al., 2017). More importantly, they behave as food sources and breeding sites for urban animal species (White et al., 2005;Suhonen et al., 2017), act as movement corridors for species between urban areas and natural forests (Fernández-Juricic, 2000), and finally have increased urban animal diversity (Ikin et al., 2013;De Castro Pena et al., 2017;Wood & Esaian, 2020). However, we found that on average, over one third of the street trees in most cities of China come from just a single species, and nearly 40% of the total individual trees are nonnative species, indicating that most cities underperform with respect to biodiversity conservation. ...
... Similarly, the proportion of non-native trees in two districts of Fortaleza in Brazil is 95.5% (Moro & Westerkamp, 2011). The proportion of nonnative trees is increasing rapidly due to globalization and fast urban development (White et al., 2005;van Kleunen et al., 2018). Native eucalypts in Australian streets have been replaced by oak trees and elms that provide more sun in the winter (Ikin et al., 2013). ...
... In addition, newly established cities with high population density tend to establish more new streetscapes and replace the ancient trees with non-native species. Consequently, old streetscapes support fewer introduced tree species than recently developed streetscapes (White et al., 2005). Considering that many cities in developing countries are under rapid urbanization, non-native species that are more affordable and available in nurseries and will be more likely to be used as street trees, increasing the pressure on biodiversity conservation. ...
Article
Urban areas are home to more than half the world’s population, but also habitats for a wide range of plant and animal species. While street trees in urban areas have been recognized as important for human well-being, however, how they can contribute to wildlife conservation is less explored. Here we compiled a database of street tree inventories in China, that included species diversity, abundance and origin information of street trees from 59 cities to explore how different cities rank with regards to the use of native and diversity of street trees, which are both considered beneficial to urban biodiversity. We found the most abundant species contributed an average of 35.8% of all street trees in the studied cities, and non-native species contributed an average of 40.6% of the street trees. Most cities are dominated by only a few species of trees, and a large proportion of these trees are non-native tree species, indicating that streetscapes are likely not friendly to biodiversity. Our proposed ranking schedule provides an easy tool for classifying cities according to their street tree wildlife friendliness, while also providing clear management directions on how to improve city tree composition for biodiversity conservation. To build a sustainable society in which nature and humans can coexist, we recommend that city planners should consider biodiversity conservation as a core value of urban planning. Specifically, we encourage the planting of more native trees and use of a more diverse set of species capable of attracting wildlife, thus promoting biodiversity in cities. Furthermore, awareness of biodiversity friendly tree planting systems needs special attention in developing regions and densely populated areas. We emphasize that more regional research needs to go into identifying local species that can be used as street trees while simultaneously functioning as wildlife attractants.
... However, the argument that parks act as refuges for bird species is well-supported (Ferná ndez-Juricic and Jokimä ki 2001). Remnant vegetation within urban areas, especially native cover, facilitates persistence of native species and higher diversity, even at small scales such as along streetscapes (White et al. 2005). Parks can also increase habitat connectivity, acting as stepping-stones between habitats (Ferná ndez-Juricic and Jokimä ki 2001). ...
... Each survey consisted of a 50 m line-transect (e.g. White et al. 2005) that was walked for 5 min. All birds seen or heard within 50 m of the transect line, and any birds seen or heard beyond the 50 m truncation (Ralph, Sauer, and Droege 1995) were identified to species using binoculars (Monarch 5 8 Â 42). ...
... Species richness and abundance Analyses were carried out on bird species richness (cumulative number of species seen during five surveys) and on avian abundance (the average number of individuals of each species seen in each park during five surveys, summed across all species observed in the park) (e.g. Crooks, Suarez, and Bolger 2004;White et al. 2005;Biadun and Zmihorski 2011). All avian species were assigned resident or migrant status based on their winter ranges. ...
Article
Full-text available
Urban development alters landscape structure and available resources, potentially threatening avian diversity worldwide. However, it is unclear how bird communities respond in areas currently undergoing urban development, particularly in the non-breeding season. We examined avian communities at 8 parks in urban (within established urban matrix; >50% built cover) and 9 parks in exurban (within adjacent grassland; 5–20% built cover) areas in Sacramento County, CA. We measured bird species and abundance, conducting five line-transect surveys per park (85 total). We investigated factors influencing avian assemblage, including local habitat features (land cover, number of trees, fruiting trees and tree species, tree height and diameter at breast height, park size, park age), and landscape features (land cover within 500 m and distance to riparian habitat). Fifty bird species, including 15 migrants, were observed. Total species richness and abundance at urban and exurban parks was not significantly different, but community assemblages differed significantly. Park area positively predicted species richness. Abundance was negatively associated with in-park percent built cover, average number of fruiting trees and landscape-scale percent water cover. Species composition changes were associated with distance to riparian habitat and landscape percent grass cover for all but one exurban park; and with tree height, DBH and park and landscape percent tree cover for urban parks. The expansion of exurban areas in many parts of the world poses a significant risk for natural habitat loss. Parks in such areas should be planned to harbor some of the displaced biodiversity.
... Nevertheless, the linear stretches of green spaces formed by roadside plantations are an integral habitat feature of urban areas (Gonzalez Sosa et al. 2017), which increase the functional connectivity to the local fauna (Ikin et al. 2015). Urban streetscapes are also known to support diverse avian communities (White et al. 2005). However, there is a clear paucity of studies on avian diversity in urban streetscapes from highly populated countries with intense population explosion and rapid urbanization, like India. ...
... Our observed avian species were divided into seven guilds, i.e. carnivore (Car), omnivore (Omn), frugivore (Frug), herbivore (Herb), nectarivore (Nect), granivore (Gran) and insectivore (Ins), following Ali and Ripley (1987). In urban areas, trees (White et al. 2005), canopy cover ( (Johnson et al. 2012) and building density (Germaine et al. 1998) and other urban structures (Ortega-Álvarez & MacGregor-Fors 2009) are known to potentially influence the diversity and abundance of avian communities present there. Hence, the habitat features like numbers of trees, bushes, waterbodies (any permanent water sources like inland waterbodies, pond, artificial, natural lake, canal which potentially influence bird abundance), buildings and markets (permanent commercial places demarcated by municipal corporation) present within each of the belt transects were assessed from the cloud free high-resolution satellite image of Kolkata (Image acquisition: 24.11.16) ...
... Moreover, amongst various land use features, the increasing number of trees also increased the species richness and abundance of birds during the present study. Several authors found that trees in urban areas usually attract the moderately abundant species (Jokimäki 1999, MacGregor-Fors et al. 2010 Urban bird communities highly depend on the structure and type of vegetation (White et al. 2005). Abundance of bird species are positively influenced by the richness of native tree species (Chace & Walsh 2006, Paker et al. 2014. ...
Article
Full-text available
In human-dominated landscapes, roads are known to negatively influence birds causing decline in species richness, as well as reduction in the number of avian species. However, linear stretches of green spaces formed by roadside plantations in urban streetscapes can support diverse avian communities. In spite of being an integral habitat feature of urban areas, there is a clear paucity of studies on avian diversity in urban streetscapes. The present study was carried out in Kolkata, where data on avian species richness and abundance was collected from 16 randomly placed belt transects (replicates), each of 500 m length and 20 m width, on different major roads throughout the study area keeping a minimum gap of 200 m between adjacent transects to avoid data overlapping. Each of these transects were traversed on foot twice in a month from January to March 2017 during days with calm weather conditions. We recorded 31 species of birds belonging to 8 orders and 19 families, of which maximum species belonged to the order Passeriformes (13 species). We found that both abundance and species richness of birds in transects with higher number of trees (78±4.1 individuals and 19.55±1.703 species of birds) were significantly higher than transects with fewer trees (53.74±2.5 individuals and 9.5±0.789 species of birds). Amongst various habitat features along these streetscapes, the total number of trees positively influenced both species richness (GLMM: F 1, 90 =14.485, P<0.05) and abundance of birds (GLMM: F 1, 90 =8.081, P<0.05). However, the other land use variables (i.e. number of bushes, waterbodies, markets and buildings) neither influenced the abundance of birds nor the species richness. Our findings can be useful for urban development to perceive the importance of various habitat features in urban streetscapes in sustaining avian diversity. Available online: http://www.ornis.hu/articles/OrnisHungarica_vol29(1)_p20-32.pdf
... Birds are one of the most studied taxa in urban areas (Faeth et al., 2011) due to they respond to environmental changes and are easy to sample (Browder et al., 2002;White et al., 2005). Birds also provide ecosystem services such as pollination, seed dispersal, and pest control, and bird species richness has a positive impact on human well-being (Fuller et al., 2007;Luck et al., 2011;Sekercioglu, 2006;Whelan et al., 2008). ...
... Birds also provide ecosystem services such as pollination, seed dispersal, and pest control, and bird species richness has a positive impact on human well-being (Fuller et al., 2007;Luck et al., 2011;Sekercioglu, 2006;Whelan et al., 2008). Bird use of wooded streets has been little studied, in most cases focusing on species richness and abundance in developed countries (Tzilkowski et al., 1986;Fernández-Juricic, 2000a;White et al., 2005;Murgui, 2007;Ikin et al., 2013;Barth et al., 2015;Shackleton, 2016;Wood and Esaian, 2020). Hence, the analysis of bird communities in wooded streets of Neotropical cities is imperative. ...
... Some studies performed on wooded streets have found that bird species richness and abundance are positively related to the number, richness, and height of trees (de Castro Pena et al., 2017;Murgui, 2007;Tzilkowski et al., 1986). Another important aspect is the origin and age of trees; wooded streets with native and mature trees have a higher functional richness and bird abundance (Barth et al., 2015;de Castro Pena et al., 2017;Ikin et al., 2013;Shackleton, 2016;White et al., 2005). Larger trees and dense canopy cover would provide more food resources and refuge for nesting birds (de Castro Pena et al., 2017;Murgui, 2007;Tzilkowski et al., 1986), providing habitat for birds associated with tree canopy cover, like the Picazuro Pigeon (Patagioenas picazuro) and the Rufous-bellied Thrush (Turdus rufiventris) (Leveau and Leveau, 2005). ...
Article
Wooded streets diminish the negative consequences of urban growth on biodiversity. However, bird use of wooded streets has been little studied, in most cases analyzing bird species richness and abundance in developed countries. In this study, we analyzed the relationship between environmental variables of wooded streets of Buenos Aires City (Argentina) and bird taxonomic and functional diversity as well as species and functional trait composition. We placed 26 100 m x 50 m transects within the wooded streets of the urban center. Bird surveys were performed during the austral spring and summer. Species richness, Pielou’s evenness, Shannon index, Functional dispersion (FDis), and species and functional trait composition were analyzed. Taxonomic and functional diversity were negatively related to pedestrian and motorized vehicle traffic. On the other hand, taxonomic diversity was related positively to streets with varied tree heights. Native taxonomic diversity and functional diversity increased near green areas. High building coverage negatively influenced the native taxonomic diversity. Bird species associated with humans, such as the Rock Dove (Columba livia) and the Eared Dove (Zenaida auriculata) increased their abundances in sites with high pedestrian and motorized traffic. The House Wren (Troglodytes aedon), the Baywinged Cowbird (Agelaioides badius), and the Red-bellied Thrush (Turdus rufiventris) were positively related with varied tree heights. Birds that feed on the ground and the undergrowth were negatively influenced by high building coverage. It is imperative to preserve green areas and to control motorized vehicle traffic in order to improve the environmental quality of wooded streets for supporting bird diversity.
... Because urban areas may be defined at multiple scales, there is neither global consensus on what constitutes "urban habitat, " nor on how best to describe habitats modified by humans yet still retaining important natural elements (Croci et al., 2008;MacGregor-Fors, 2010;Evans et al., 2011;Beninde et al., 2015; but see White et al., 2005;Li et al., 2019). As a measurement of the degree of urbanization in our study area, we calculated urban cover using the "Urban/Built-Up" category in the statewide vegetation mapping dataset "CALVEG, " which was created between 2002 and 2003 (CALVEG, 2009; 1 ha mapping units). ...
... Finally, as urbanization continues to expand globally, we encourage further reflection on ways to define "success" in urban areas. On one hand, cities may be considered successful if they include built features that can support a high diversity of species, some of which would not have occurred prior to urbanization (White et al., 2005;Filazzola et al., 2019). Yet cities must also allow the least-adaptable species -those most strongly associated with wildland rather than urban habitats -to find refuge within the urban matrix as they urbanize (Sol et al., 2014). ...
Article
Full-text available
We present an analysis of life history and behavioral traits associated with urbanization for 52 breeding bird species on 173 survey blocks in the Los Angeles area of southern California, United States, across two time periods, 1995–1999 and 2012–2016. We used observational data from two community science efforts and an estimate of urban land cover in each block to develop an index of urban association, and then modeled the relationship between species occurrence and eight traits likely associated with urban tolerance. We found two traits to be significantly associated with urbanization in both eras: Structure-nesting (i.e., the tendency to build nests on human-built structures) was positively associated, and cavity-nesting (i.e., the tendency to build nests in natural tree cavities) was negatively associated. Our analysis provides a template for mining historical community science data, and for “retrofitting” contemporary data to gain insights into ecological trends over time, and illustrates the persistence of ecological traits of species associated with urban areas even as the makeup of these species communities may change.
... Many individual patches of habitat in urban areas are too small and widely dispersed to support viable populations [40]. It is therefore important that green spaces, such as gardens and public open space, are not viewed at the individual scale, but instead considered collectively as interconnected networks of green spaces across the urban landscape [41,42]. ...
... In Melbourne, like in other Australian cities, streetscapes with native trees support significantly more diverse and abundant populations of native birds than streets with mostly exotic trees [41,43]. Birds provide a useful candidate taxon for monitoring as they are relatively easy to detect and identify, census methods are well developed and formal and informal monitoring and databases in existence (e.g., [44]). ...
Article
Full-text available
Urban forests provide many ecosystem services, such as reducing heat, improving air quality, treatment of stormwater, carbon sequestration, as well as biodiversity benefits. These benefits have resulted in increasing demand for urban forests and strategies to maintain and enhance this natural infrastructure. In response to a broader resilience strategy for Melbourne, Australia, we outline how a metropolitan-wide urban forest strategy (Living Melbourne) was developed, encompassing multiple jurisdictions and all land tenures. To this end, we mapped tree cover within the Melbourne metropolitan area, modelled potential habitat for some bird species, and investigated the role of tree cover for urban heat island mitigation. We outline the consultation and governance frameworks used to develop the strategy, the vision, goals and actions recommended, including canopy and shrub cover targets for different parts of the metropolitan area. The metropolitan-wide urban forest strategy acts as an overarching framework to guide local government authorities and various stakeholders towards a shared objective of increasing tree cover in Melbourne and we discuss the outcomes and lessons from this approach
... The species common in urban landscapes are exotic exploiters or general native species tolerant to various urban conditions (White et al., 2005;Antos, 2006;McKinney, 2006). Resident species dominated the bird community in the city center and made up over 90% of the species observed. ...
... Since vegetation is usually exotic, there is an increase in the diversity of exotic bird species. However, sometimes, native vegetation allows for a higher proportion of native bird species (White et al., 2005;Chace and Walsh, 2006;Daniels and Kirkpatrick, 2006;Threlfall et al., 2016). Although the variance in this study is not statistically significant, when consideration is given to observed bird species and plant species, the number of native bird species was found to be higher in the Pinarbasi Recreation Area and Aytepe Recreation Area on the urban fringe where there were more native tree species, which was due to the fact that high diversity in natural vegetation provided more nesting space, shelter, and food for many bird species (Chong et al., 2014). ...
Article
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Among wildlife species, birds are important indicators of biodiversity and habitat quality in urban ecosystems. Parks, which are among the important components of urban ecosystems, are home to many bird species with their diversity of plant species. Due to this aspect, parks make significant contributions to increase bird diversity. The bird species were observed with the naked eye and using an Olympus 10x50 DPS I brand binocular. Bird observations were performed on sunny days without rain and excessive wind in the mornings (07.00-09.00 a.m./2 h after sunrise) and evenings. Sixteen bird species observed in urban parks of Aydin comprised 11 native, 11 resident and 9 insectivorous species. The Eurasian Collared-Dove (Streptopelia decaocto Frivaldszky), Eurasian Jackdaw (Corvus monedula L.), Hooded Crow (Corvus cornix L.), Great Tit (Parus major L.), and House Sparrow (Passer domesticus L.) were the most frequently observed bird species in all parks. The Australian Pine (Casuarina equisetifolia L.) attracted the highest number of bird species with 12 species, followed by the Turkish Pine (Pinus brutia Ten.) with 11 species. A significant variance was found between plant species and avian diversity.
... Typically, this is through the amenity and cooling of street trees but bioretention systems to improve water quality are also common on streets in many cities (Kazemi et al. 2011;Laurenson et al. 2013). Increasingly, streetscapes are also being recognised as opportunities to improve habitat (White et al. 2005) and ecological connectivity (Fernandez-Juricic 2000). ...
... Increasing the structural complexity of understorey vegetation, and planting native species, has positive effects on bat, bird and insect communities in Melbourne (Threlfall et al. 2017;Mata et al. 2021). Therefore, planting native understorey to establish multiple layers of vegetation which are normally absent on streets, could provide many benefits to fauna, including a greater variety of foraging, breeding and sheltering resources (Tews et al. 2004;White et al. 2005 Aronson et al. 2017) and there are real or perceived barriers to its implementation on streets (Marshall et al. 2020). For the City of Melbourne these have included potentially high construction and maintenance costs, safety concerns regarding dense vegetation and the risks of vegetation death due to the hostile growing conditions of streetscapes that would then result in negative public perceptions and further maintenance and renovation expenditure. ...
Article
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Underutilised public spaces such as streetscapes offer substantial opportunities to integrate habitats that increase biodiversity into existing urban landscapes and create more ecologically connected cities. Cooperation and collaboration from diverse stakeholders are paramount to achieving this because growing conditions for plants in streetscapes are often much harsher than remnant habitats or urban parks and little is known about the horticultural performance of many native understorey species in these novel urban environments. This paper describes how the City of Melbourne collaborated with researchers from the University of Melbourne to develop and test a suite of understorey plant species to increase streetscape biodiversity. To do so, we selected species using criteria from a horticultural planting guide which guided the design and creation of four streetscape plantings within the municipality. Here, we document the process and discuss lessons learnt from this project to assist other cities to design, construct and maintain streetscapes with successful, cost-effective plantings that improve urban biodiversity and aesthetic value. Key to the long-term success of these biodiverse plantings was thorough soil preparation and weed management before planting, and the implementation of a clear, ecologically sensitive management plan. To support this plan, suitably qualified and experienced landscape maintenance staff were essential, particularly those with horticultural knowledge and experience with indigenous and native plant species. Our project highlights the often conflicting needs of local authorities and ecological researchers and the necessary trade-offs needed to meet realistic goals and achieve successful project outcomes for creating more biodiverse urban landscapes.
... Urbanization is considered as the leading force behind habitat fragmentation and degradation (Seress & Liker 2015, Leveau & Leveau 2016, Hensley 2018) but its consequences on avian biodiversity are studied only sparingly in Pakistan (Joshua & Ali 2011, Ali et al. 2013, Khan et al. 2014, Abbasi et al. 2015, Ali et al. 2016, Altaf et al. 2018. Urban expansion has impacted local avian species dynamics worldwide (Rottenborn 1999, Melles et al. 2003, White et al. 2005, Chace & Walsh 2006, Aronson et al. 2014, Peck et al. 2014. ...
Article
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Diversity in avian assemblages of urban (UR), peri-urban (PE) and rural (RU) areas was studied to explore variations in the avian community dynamics in rural – urban gradient. For this purpose, sampling was done from September 2013 to August 2015. A total of 35 sites, each covering an area of 300 m ² were sampled by using point count method. At each site, randomly three points (minimally 5 m apart from each other) were selected to study the birds. According to data, species richness (F 2, 32 =47.18, P<0.001) varied significantly along a rural-urban gradient. A significant difference in avian density per sampling site (F 2, 32 =105.41, P<0.001) was also observed along urbanization gradient. In PE and RU areas, avian assemblages were more diverse than UR areas. Among avian guilds, omnivores were the most abundant in UR while insectivores in PE areas. Frugivores and carnivores were abundant in RU areas. Granivores were recorded in all habitats with similar diversity. A close association was recorded in bird density of RU and PE areas than UR areas. Bird species richness and diversity showed negative correlation with built area and positive correlation with vegetation cover in an area.
... Forest provides many ecosystem services (Shvidenko et al., 2005). The alteration from native to exotic streetscapes saw the liberal damage of insectivorous and nectarivorous bird types reflecting a faith by these species on structurally varied and/or native vegetation for both shelter and food resources (Antos et al., 2003). ...
Article
Birds have very close association with trees. Trees offer a platform to birds for nesting, roosting, foraging, breeding and feeding purposes. The introduction of exotic (non-native) flora can effect or modify inherent species richness, communal alignment and species abundance, as well as species relationships and communal structure. Birds are exclusively sensitive to alterations both in terms of environmental and ecological. Introduction of exotic trees and human disturbance have also affected the bird diversity. The main objective of the present study was to find out the nesting preference of avian species in relation to exotic trees at two selected locations i.e. Punjab Agricultural University, Ludhiana (Location I) and Gurpal Nagar, Ludhiana (Location II) from June 2018 to July 2019. Five different exotic trees species selected were Safeda (Eucalyptus tereticornis), Poplar (Populus deltoides), Bottle brush (Callistemon viminalis), Monkey Puzzle (Araucaria araucana), Silver Oak (Grivillea robusta). A total 31 nests (6 on Bottle brush tree, 2 on Silver oak tree, 7 on Poplar tree, 16 on Eucalyptus tree) were recorded. Out of these, 5 nests were of Baya weaver Ploceus philippinus, 4 nests were of Rose-ringed Parakeet Psittacula krameri, 20 nests were of House Crow Corvus splendens and 2 nests were of Common Myna Acridotheres tristis. Four bird species were observed nesting at location I while only one was observed at location II. Less bird diversity recorded was at location II (8) as compared to location I (23) because of the anthropogenic activities which disturbed the natural habitat at that location.
... The distribution of habitat, and more specifically roosting habitat, could be greatly enhanced on private land particularly when in close proximity to river systems. Structural diversity of garden vegetation has been recommended to increase nesting, foraging and shelter opportunities for many urban bird populations (Marzluff and Ewing, 2001;White et al., 2005), while native and indigenous vegetation provides owls with a year-round roosting resource, compared to exotic deciduous tree species. Urban wildlife habitat on private land is largely reliant on landowners, and municipal planning regulations to ensure suitable resting habitat is retained and available. ...
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Increased urbanisation is placing respite areas for wildlife under stress, with the impact of anthropogenic disturbances such as noise, artificial light and infrastructure compounding as urban areas expand and become more populated. One essential, and sometimes overlooked behavioural activity is where urban wildlife sleep or rest. This is especially important for urban predators that are wide-ranging and exhibit specific ecological requirements. The powerful owl (Ninox strenua) is one such species. To ensure the future survival of urban powerful owls it is critical that we understand where they choose to roost/sleep and why. To determine these roosting characteristics, we used roosting data collected from GPS tagged powerful owls across Melbourne, Australia and examined these data at different spatial scales to provide a holistic understanding of habitat selection. At the landscape scale, potentially suitable roosting habitat was restricted heavily by urban and agricultural land use. Population-wide, roosts were located within dense tree cover with some flexibility between individuals in distance to river systems and tolerance of road density. At the microhabitat-scale, individual owls displayed flexibility by roosting in a variety of indigenous, non-indigenous native and exotic tree species. These considerations will assist urban planners to conserve suitable roosting habitat, while restoration efforts should be prioritised on private land and along river systems where roosting habitat can be enhanced and expanded, increasing landscape connectivity for other wildlife.
... The moths recorded at each garden site were dominated by a few species, irrespective of habitat complexity, reflecting the abundance of generalist species (accounting for approximately 84% of the species recorded based on larval food plant preferences; (Parson et al. 2012;Waring and Townsend 2017;supplementary material, S3) that are adapted to urban environments (McIntyre 2000;McIntyre et al. 2001). The relatively homogenous urban habitat does not support a diverse assemblage of specialist moth species because it cannot provide the variety of plant species found in natural habitats (Davey et al. 2012). ...
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‘Wildlife-friendly’ gardening is a dominant theme in the media that readily engages public attention. However, there is little empirical evidence of the ecological benefits of increased habitat quality of individual domestic gardens. This study uses light-trapping to examine the response of moth assemblages to domestic gardens that are assessed in terms of their habitat complexity (simple and complex) both within the garden and extending out to a 30 m radius that includes surrounding habitats. The results clearly show that moth assemblages were influenced by complex habitats (particularly increasing levels of the variable shrubs and decreasing levels of artificial surfaces), but only at a scale that extended beyond the garden boundary to include the surrounding area. In other words, neither the complexity of the habitat within the garden or the size of the garden had any influence on the abundance or diversity of the moth assemblage. These results have implications for both garden management and landscape planning – if domestic gardens are to be a useful component of strategies to reduce biodiversity loss within the urban environment then they should provide good habitat quality and be managed as a network of interconnected patches rather than as individual units.
... Urban ecosystems are complex dynamic systems where humans are the dominant driving force (Alberti, 2008). Major human-induced transformations within urban areas include the clearing of vegetation, the introduction of non-native plant species, the installation of artificial structures, and the alteration of the quality and quantity of disturbances (Niemela, 2011;Parris, 2016) which can have significant effects on the spatial distribution of urban fauna (Fernandez-Juricic, 2002;Gonza´lez-Oreja et al., 2012;Ortega-Alvarez & MacGregor-Fors, 2010;White et al., 2005). In the face of global urbanization trends (Fragkias et al., 2013), understanding the factors that drive biodiversity patterns in urban areas has become paramount for both environmental science and policy. ...
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Given current urbanization trends, understanding the factors that affect local biodiversity is paramount for designing sound management practices. Existing evidence suggests that the assembly of urban communities is influenced by the environmental filtering of organisms based on their traits. Here, we investigate how environmental characteristics including isolation measurements affect the functional composition of avian assemblages in green spaces of Merida, Mexico, a Neotropical city. We sampled 22 sites, analyzed point-count data collected during fall migration, and characterized the habitat with regard to floristic and structural vegetation attributes, vegetation cover within green spaces, urban infrastructure, and isolation. We assessed the relationship between habitat descriptors and bird functional traits using RLQ and fourth-corner tests and compared trait–environment associations between resident and wintering species. Our results showed that functional composition of resident bird assemblages was linked to the environmental characteristics of the site, while the functional composition of wintering species was not. In particular, the degree of isolation revealed to be an important determinant of trait composition. Plant species richness, particularly native tree and shrub species, were critical for the functional composition of resident birds in green spaces. Our findings suggested shifts in body mass from less to more isolated green spaces. Specifically, we observed that large-bodied species predominated in isolated green spaces. This information is useful given the predicted increases in habitat isolation and transformation of green spaces due to urbanization.
... Subtropical forests were species rich, and the protected areas, Ramnagar Wildlife Sanctuary and Bahu-Mahamaya forest mostly harbored forest specialists. The urban forested areas attracted a large number of migratory as well as resident birds (Grimmett and Inskipp 2007;McKinney 2008;Evans et al. 2009) as the forest fragments (Donnelly and Marzluff 2004), gardens (Gaston et al. 2005;White et al. 2005), tree-lined avenues, and residential yards (Savard et al. 2000;Belaire et al. 2015;Tiwary and Urfi 2016) harbor more bird species. These natural habitats in urban matrix function as a refuge for woodland species (Croci et al. 2008), enhance the abundance of food resources, and provide nesting opportunities including cavities (Mörtberg and Wallentinus 2000). ...
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Land-use sprawl in the Himalayas has caused the conversion of natural habitat into human-modified habitats, thus degrading ecosystem health. Adaptation of birds to changing physical environment can be well understood by analyzing their habitat preferences, and foraging dynamics explored to a limited extent in the Himalayan region, as yet. To achieve a comprehensive understanding of avian guild structure, we used multivariate statistical techniques to classify bird species according to their similarities in foraging patterns and habitat preferences. Observations based on habitat and diet affinities accounted for rich avian diversity with a total of 208 bird species (about 15% of country's avifauna) recorded from six different sites during 1 year survey. Unweighted pair-group average cluster analysis performed on the families revealed ten feeding and fifteen habitat guilds among 63 bird families observed. Subtropical forests harbored more species followed by urban forests and agricultural landscapes. Insectivorous and omnivorous outnumbered other feeding guilds in the study area. Bird assemblages were richer in protected areas and semi-disturbed landscapes and did not show significant variation between the seasons. Results of the study revealed that different functional groups of birds behaved differently, primarily induced by choice of food. The site heterogeneity favored avifaunal persistence by providing favorable foraging, roosting, and nesting opportunities to birds. Composition of avian guilds indicated level of intactness and ecological integrity of ecosystems studied. This outcome thus sets the background for long-term analysis of bird-habitat relationship and their foraging dynamics. The study has the relevance for decision-makers to integrate avian guild structure as an essential ingredient in formulating conservation strategies.
... Most of the non-domesticated species that adapt to the urban environment present interesting case studies to understand how they resolve issues of conflict with humans while exploiting new niches created in these human-dominated landscapes. This question is all the more interesting for species like birds and mammals, in which decision making might be influenced by their experiences from interactions with humans in the urban space (Ditchkoff et al., 2006;Maklakov et al., 2011;White et al., 2005). ...
Preprint
Dogs ( Canis lupus familiaris ) are the first species to have been domesticated, and unlike other domesticated species, they have developed a special bonding with their owners. The ability to respond to human gestures and language is a key factor in the socio-cognitive abilities of dogs that have made them our best friend. Free-ranging dogs provide an excellent model system for understanding the dog domestication process. In India, free-ranging dogs occupy every possible human habitation, and interact with humans regularly. They scavenge among garbage, beg for food from humans, give birth in dens close to human habitations, and establish social bonds with people. However, there is ample dog-human conflict on the streets, leading to morbidity and mortality. Hence the ability to assess an unfamiliar human before establishing physical contact could be adaptive for dogs especially in the urban environment. We tested a total of 103 adult free-ranging dogs to investigate their response to immediate and long-term food and social rewards. The dogs were provided a choice of obtaining a food reward either from the hand or the ground. The dogs avoided making physical contact with the unfamiliar human. While immediate rewards were not effective in changing this response, the long-term test showed a strong effect of the social reward on the response of dogs. Our results revealed that dogs tend to build trust based on affection, and not food rewards. This study provides significant insights into nuances of the dynamics that could have paved the path to dog domestication.
... Forest provides many ecosystem services (Shvidenko et al., 2005). The alteration from native to exotic streetscapes saw the liberal damage of insectivorous and nectarivorous bird types reflecting a faith by these species on structurally varied and/or native vegetation for both shelter and food resources (Antos et al., 2003). ...
... The growth of human population decreases the GGL habitat. White et al. (2005) stated that most of the deforestation activities ignore the wildlife in the forest, and sadly, it happens in almost all continents. This matter extremely threatens the birds that needed a wide space and dense vegetation to support their life (Peris and Montelongo 2014). ...
... Anthropogenic features, mostly land cover, rather than non-anthropogenic factors (such as geography, climate, and topography) are responsible for decreasing species density, indicating that vegetation structure plays a crucial role for animal conservation in urbanized areas; Aronson et al. (2014) pointed it out in the case of birds. Other evidences report that recently developed peripheries, poorly vegetated or characterized by exotic plant species, which provide less adequate resources, host a lower bird diversity (White et al., 2005;Evans et al., 2009;Fontana et al., 2011;Shwartz et al., 2013;Taylor et al., 2013;Barth et al., 2015). ...
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It is well-acknowledged that plants in urban areas provide multiple ecosystem services. They contribute improving ambient quality and mitigating negative impacts of human presence, beautifying the anthropic environment, and promoting place identity and cultural heritage. However, the existence of plants in general, and trees in particular, cannot be considered independent on urban activities and infrastructures. Release of plant volatile compounds is profoundly affected in urban environments, in turn modifying plant relationships with other living organisms, both plants and animals, and affecting air chemistry and quality. Plants also interfere with stone artifacts, cultural and historical heritage. Plant-human coexistence requires precise and adequate managing measures, which have often been ignored in cities' government and planning. Plants and humans (and human infrastructures) are frequently considered as independent from each other and plant requirements are often disregarded, thus causing difficult or erroneous management and/or environmental damage. We review some of the most important ecosystem services provided by plants in urban environment, and also focus on possible negative effects of plants that may become relevant if urban vegetation is improperly managed and unintegrated in proper city planning, both of historical centers and of new towns or suburbs.
... The impacts of changing plant community compositions due to invasive plants are also evident at other trophic levels. For example, the abundance of native insectivorous and nectarivorous bird species decreased where the urban streetscape is dominated by non-native plants (White et al. 2005). Also, native insects have been shown to be in lower abundance on non-native plants than native plants (Zuefle et al. 2008). ...
Chapter
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Long-term management strategies are invoked once an invasive species has become established and spread beyond feasible limits for eradication or containment. Although an invasive species may be well-established in small to large geographical areas, prevention of its spread to non-affected areas (e.g., sites, regions, and cross-continent) through early detection and monitoring is an important management activity. The level for management of established invasive species in the United States has increasingly shifted to larger geographical scales in the past several decades. Management of an invasive fish may occur at the watershed level in the western States, with watershed levels defined by their hydrologic unit codes (HUC) ranging from 2 digits at the coarsest level to 8 digits at the finest level (USGS 2018). Invasive plant management within national forests, grasslands, and rangelands can be implemented at the landscape level (e.g., Chambers et al. 2014), although management can still occur at the stand or base level. Landscapes in this chapter refer to areas of land bounded by large-scale physiographic features integrated with natural or man-made features that govern weather and disturbance patterns and limit frequencies of species movement (Urban et al. 1987). These are often at a large physical scale, such as the Great Basin.
... Maximising retention of remnant areas when planning newly developing suburbs as well as restoration of natural areas on unused open space or sites decommissioned from other uses have significant positive impacts for nature and needs to be incentivised (Allison 2018). For these processes, it is important for urban planning to consider ecological and biodiversity evidence, research and monitoring, as well as to tap into interdisciplinary knowledge of planners and ecologists (White et al. 2005;Bohnet 2010;Williams et al. 2021). This is specifically relevant for small and medium size cities in Australia located in proximity to remnant natural areas and ecosystem reserves that post-pandemic may seem as desirable areas for peri-urban development. ...
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Australia is experiencing mounting pressures related to processes of urbanisation, biodiversity loss and climate change felt at large in cities. At the same time, it is cities that can take the leading role in pioneering approaches and solutions to respond to those coupling emergencies. In this perspective piece we respond to the following question: What are the required transformations for prioritising, valuing, maintaining and embracing nature in cities in Australia? We adopt the mission framework as an organising framework to present proposed pathways to transform Australian cities as nature-positive places of the future. We propose three interconnected pathways as starting actions to steer urban planning, policy and governance in Australian cities: First, cities need to establish evidence-based planning for nature in cities and mainstream new planning tools that safeguard and foreground urban nature. Second, collaborative planning needs to become a standard practice in cities and inclusive governance for nature in cities needs to prioritise Aboriginal knowledge systems and practices as well as look beyond what local governments can do. Third, for progressing to nature-positive cities, it is paramount to empower communities to innovate with nature across Australian cities. Whilst we focus on Australian cities, the lessons and pathways are broadly applicably globally and can inspire science-policy debates for the post COP15 biodiversity and COP26 climate change implementation processes.
... Malgré cela, les rues urbaines peuvent héberger une très grande variété d'espèces animales et végétales qui colonisent les microsites existant ou utilisent, pour se déplacer, ces corridors routiers comme parties de réseaux d'habitats urbains (Säumel et al., 2015). Ces corridors urbains végétalisés, généralement discontinus, « en pas japonais », peuvent réduire l'isolement des habitats semi-naturels en ville (White et al., 2005), où des populations végétales sont affectées par la fragmentation de leur habitat (Dubois et Cheptou, 2016) mais aussi par la colonisation à partir d'habitats proches ou plus éloignés (Dornier et al., 2011). Cependant une autre étude met en relief l'homogénéisation de la végétation spontanée des pieds d'arbres dans le monde (Wittig et Becker, 2010). ...
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This article presents research conducted on the vegetation associated with trees in urban wooded areas, and its relationship to the landscape in a medium-sized city: the agglomeration of Tours. An in-depth study of the vegetation of urban wooded areas made it possible to study the links between this flora and 1) the urban spatial structure (central and peripheral wooded areas) and 2) the internal spatial structure of wooded clusters (central and outlying zones). The urban structure plays a dominant role in the botanic compositions of the woodland undergrowth: the central wooded areas (surrounded by a high proportion of urbanised surfaces) harbour almost all the horticultural species present, thus contributing to their diversity. The peripheral woods, extensive and mainly surrounded by cultivated land, do not present a higher degree of diversity compared to the central wooded areas. The proportion of woodland surface area compared with the urbanised surface areas adjacent to wooded areas of varying radiuses, are major factors in the botanic compositions of urban woods. In the interrelation between the internal spatial structure of urban wooded areas and the vegetation of the woods, the outskirts of the woods have a specific diversity which is greater than that of the central zones, even though the plant communities of the central and outlying zones are very similar. Our results confirm elements identified in large agglomerations: spontaneous vegetation in urban wooded spaces is linked to the structure of the urban landscape; urban forestry management strategies should take into account the colonisation process of semi-natural vegetation at the level of the landscape.
... Com relação a origem das espécies amostradas cerca de 73% das espécies não são nativas do estado, o que totaliza 92,7% de todos os indivíduos. É importante que o município passe a investir no plantio de árvores nativas, pois estas parecem contribuir para o aumento da riqueza e abundância de espécies nativas da fauna, e as comunidades passam a se assemelhar mais àquelas de habitats naturais do que em ruas que são compostas predominantemente por espécies de árvores exóticas (WHITE et al., 2005). ...
... These low-density areas (particularly suburbs) typically support high species richness (Catterall, Cousin, Piper and Johnson). Australia is also one of the few countries to have urban vegetation assemblies that significantly differ from surrounding local native floral assemblies (Aronson 2014), which has been noted to further alter Australian urban bird assemblages (White et al. 2005). As such Australian urban ornithological studies likely include a greater diversity of species than elsewhere globally. ...
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As the global footprint of urban areas expands, there is increasing motivation to conserve biodiversity in these areas. Cities typically develop in fertile, biodiverse locations, and often contain relatively high numbers of threatened species. Despite this, urban landscapes are often overlooked as conservation priorities. Although birds have been extensively studied in urban areas, research effort may not be consistent among species. An unbalanced representation of species and collective tendencies to focus on particular research topics pose a risk to the completeness of our understanding of urban ornithology. Developing a better understanding of how birds are studied in urban areas is crucial to mitigate the risk of biodiversity loss. Here, we conducted a systematic quantitative literature review to determine research effort at the species level for birds in Australian urban areas. We modelled which species characteristics predict the level of species research effort across studies with varying levels of conservation relevance and study themes. We found that studies with a strong link to conservation were uncommon and that most studies targeted broad suites of species rather than specific groups or species. Species characteristics, including species taxonomic group, migratory behaviour, threat status and body mass, were significant predictors of research effort. These results highlight the biases that exist in urban bird research, showing that applied conservation is uncommon and usually broad. Understanding the biases in Australian urban ornithology establishes a foundation for expected biases on other continents, which once addressed will be beneficial to conserving urban bird biodiversity.
... Given the timeframe for this project and the lack of relevant field data, we used existing ecological knowledge to parameterise resistance of different land uses for the superb fairy-wren and growling grass frog (following guidance from Spear et al., 2010). Resistance values were assigned differently for our two target species to account for their different resource and habitat requirements and their different movement capabilities (Hale et al., 2013;Harrisson et al., 2013;Heard et al., 2012;Watson et al., 2008;White et al., 2005). We followed a similar rationale to Grafius et al. (2017), who assigned resistance based on land use. ...
Article
Biodiversity within cities is fundamental for human health and well-being, and delivers a wide range of critical ecosystem services. However, biodiversity is often viewed as an afterthought or final addition once an urban development nears completion. As such, provisions for biodiversity are typically tokenistic and do not achieve the experience of everyday nature that people need. Considering biodiversity requirements at the start of an urban development allows for strategic, intentional design with biodiversity enhancement in mind. Biodiversity Sensitive Urban Design (BSUD) is a protocol that aims to create urban areas that deliver on-site benefit to native species and ecosystems through the provision of essential habitat and food resources. Here we present a case study demonstrating how BSUD methods can be used to (a) encourage successful outcomes for nature, (b) improve the aesthetics and liveability of the urban form, and (c) engage stakeholders in a process that supports other aspects of urban design including park and streetscape design. Fishermans Bend (Melbourne) is the largest urban renewal project in Australia, and one of the first of this scale to explicitly include biodiversity targets. We outline the methods used to co-create biodiversity objectives with diverse stakeholders, and how these, combined with a quantitative analysis of their potential biodiversity impact, were translated into clear design and planning recommendations. We critically reflect on the success of this method for 1) communicating and facilitating provisions for biodiversity across different stakeholders and 2) providing clear messaging around biodiversity across different planning disciplines.
... Further, we did not investigate the influence of exotic tree species. Most of our tree species were native, but there is evidence from other regions like Australia, that exotic plants can negatively impact bird richness and change communities (White, Antos, Fitzsimons, & Palmer, 2005). Consequently, there is scope for further trait-based studies to investigate the effects of trees on urban birds in more detail. ...
Article
Cities are designed for humans but are also highly dynamic ecosystems that provide habitats for wild animals. These habitats depend on a city's green infrastructure which is increasingly threatened by urban densification. A commonly studied model taxon for wild animals in cities are birds, and the importance of large green spaces for the diversity of birds in cities has been shown. However, how small-scale green spaces affect bird communities, which local characteristics are important, and whether there are seasonal differences remains unclear. We asked how and to what extent the characteristics of city squares in Munich affect the diversity and abundance of birds and if there are differences between bird communities in spring, autumn, and winter. We monitored birds on 103 city squares in Munich using a search-route method. Sampled squares spanned a spatial gradient from the center to the periphery of the city and differed in sealed surface proportion and vegetation structures, such as trees, shrubs, and lawns. The diversity and abundance of birds increased with a higher proportion of green characteristics on the square. Especially the proportion of grass cover and the density of trees had strong positive effects. Old trees had additional effects on birds beyond the effects of trees in general, while the mean number of people on a square negatively influenced bird abundance and diversity. Despite seasonal changes in bird composition, square characteristics showed consistent effects on bird abundance and diversity over seasons. These results underline that the green characteristics of city squares, and therefore of small-scale green spaces, affect their suitability as habitat for wildlife in cities. Integrating this knowledge into city planning can help to maintain or even increase urban biodiversity in the future.
... Common myna (Acridotheres tristis Linnaeus, 1766) is a species of invasive birds which thrives successfully in urban and sub-urban areas and is well-adapted to human presence (McGiffin et al. 2013) and therefore, is known to be a synurbic species (Seress and Liker 2015). They are generalist omnivorous species and exploiting the novel foraging opportunities there (Cramp and Perrins 1994;White et al. 2005;Sol et al. 2012;McGiffin et al. 2013;Grarock et al. 2014). Asian pied starling (Sturnus contra Linnaeus, 1758) is another common bird of Indian subcontinent, mainly found in the Gangetic plains and in the Himalayan foothills up to an elevation of 700 m a.s.l. ...
Article
Urbanization is noticed across the globe often leading to biotic homogenization. Birds that are able to exploit novel urban conditions to their benefit usually flourish (urban exploiters), some species are tolerant to moderate levels of urbanization (urban adapters) while others avoid and gradually decline in urban areas (urban avoiders). However, studies on the influence of habitat features on urban exploiters, adapters and avoiders are still very few. So, we made this comparative assessment of habitat-wise and seasonal patterns of abundance of common myna (urban exploiter), Asian pied starling (urban adapter) and jungle myna (urban avoider) in an urban landscape, and assessed the relationship between habitat features and weather parameters with their respective abundance. Fixed radius (50 m) point count was carried out in five different habitats (i.e. roadside habitat, residential area, market area, open fields and waterbodies) of Kolkata, West Bengal, India. Surveys were carried out twice a month from May 2019 to March 2020, wherein the number of individuals of common myna, pied starling and jungle myna were recorded for 10 min. We found that the abundance of common myna was highest followed by pied starling and jungle myna. Three species of mynas are influenced by different habitat features within an urban area. Our findings might be useful to foster sustainable management plan for many urban areas across the globe where all three species are still thriving. This study might be replicated in many urban areas across the globe for other avian species of urban exploiter, urban adapters and urban avoiders.
... The test was based on Bray-Curtis rank similarity matrix (Clarke, 1993). Similarity percentages (SIMPER) procedure in CAP 3.1 (Seaby & Henderson, 2006) was used to identify those species that contributed substantially to the average similarity within the group (Clarke & Warwick, 2001;White et al., 2005). ...
Article
en The study sought to determine the extent to which fallowing can lead to recovery towards an historic woody vegetation of Sudanian woodlands in northern Uganda. Fallow sites of three distinct ages were assessed. Plots were established in crop fields that had been under cultivation for over 10 years, sites that had been under fallow for 3–6 years (young fallow) and fallow sites of at least 9 years (old fallow) in three districts. In each plot, all woody plants were enumerated and species composition, diversity and richness assessed. Young fallow plots were dominated by pioneer species such as Piliostigma thonningii and Annona senegalensis, while old fallow by a mix of late and early successional species such as Vachellia hockii (formerly Acacia hockii) and Combretum collinum. Vitellaria paradoxa (Shea butter tree) was the most abundant in all fallow categories. Species composition in crop field was different from young and old fallow. Species richness increased significantly from abandoned Crop field to Young fallow and then to Old fallow. Simpson's Diversity Index showed similar trends. V. paradoxa contributed most to overall similarity among the fallow categories. Fallowing can facilitate restoration of characteristic species of Sudanian woodlands. Résumé fr L'étude a cherché à déterminer dans quelle mesure la mise en jachère peut conduire à la reconstitution d'une végétation ligneuse historique des forêts soudaniennes dans le nord de l'Ouganda. Nous avons évalué des sites de jachère de trois âges différents. Des parcelles ont été établies dans des champs cultivés depuis plus de 10 ans, des sites en jachère depuis 3 à 6 ans (jeune jachère) et des sites en jachère depuis au moins 9 ans (vieille jachère) dans trois districts. Dans chaque parcelle, toutes les plantes ligneuses ont été dénombrées et la composition, la diversité et la richesse des espèces ont été évaluées. Les parcelles de jeunes jachères étaient dominées par des espèces pionnières telles que Piliostigma thonningii et Annona senegalensis, tandis que les vieilles jachères par un mélange d'espèces de succession tardive et précoce telles que Vachellia hockii (anciennement Acacia hockii) et Combretum collinum. Vitellaria paradoxa (arbre à beurre de karité) était le plus abondant dans toutes les catégories de jachères. La composition des espèces dans les champs de culture était différente de celle des jachères jeunes et anciennes. La richesse en espèces a augmenté de façon significative entre les champs de culture abandonnés, les jeunes jachères et les vieilles jachères. L'indice de diversité de Simpson a montré des tendances similaires. V. paradoxa a contribué le plus à la similarité globale entre les catégories de jachères. La mise en jachère peut faciliter la restauration des espèces caractéristiques des zones boisées soudanaises.
... Parallèlement à cette diminution de la richesse des espèces natives en ville, la richesse des espèces non-natives augmente Lepczyk et al, 2008 ;Van Rensburg et al, 2009 ;White et al, 2005). En Europe centrale notamment, le phénomène « d'îlot de chaleur urbain » favorise l'installation de plantes plus exotiques et/ou plus résistantes à des températures plus élevées (Hough, 1995 ;Celesti Grapow et al, 2001). ...
Thesis
L’urbanisation est l’un des phénomènes majeurs qui impactent la biodiversité à l’échelle mondiale. Les nombreuses contraintes associées au milieu urbain (perte d’habitat, changement des ressources, pollutions chimique, lumineuse et sonore, etc.) modifient la diversité et la répartition des espèces animales, et peuvent avoir de lourdes conséquences à l’échelle individuelle. Or, le développement constant du milieu urbain nécessite de mettre à jour les études sur les effets de ce milieu sur les espèces animales, et en particulier sur les oiseaux, qui rendent de nombreux services écosystémiques à l’homme. Dans ce contexte, nous avons cherché à étudier les bénéfices et contraintes du milieu urbain chez les oiseaux, en se plaçant à trois échelles différentes : biodiversité, population et individu. Dans un premier temps, nous avons réalisé une étude spatiale de la biodiversité aviaire à Niort. Nous avons pu mettre en évidence l’importance de maintenir des infrastructures vertes et connectées en ville, pour favoriser la présence des espèces communes comme celles moins adaptées au milieu urbain. Dans un deuxième temps, nous avons cherché à évaluer l’état des populations de moineaux domestiques en ville, ceux-ci étant en fort déclin dans les grandes villes européennes. À l’aide d’une étude corrélative, nous avons démontré que le milieu urbain est particulièrement stressant pour les moineaux en développement. Également, l’analyse d’un stress hydrique en conditions expérimentales nous a permis de constater que les moineaux adultes sont également très sensibles aux changements des conditions de l’environnement. Dans un troisième temps, l’application d’une contrainte du milieu urbain (pollution lumineuse) sur les moineaux au cours de la reproduction a permis de mettre en évidence des changements rapides du comportement individuel en réponse à cette contrainte. Les résultats de ces différentes approches démontrent que les effets de l’urbanisation sur les oiseaux sont complexes, et que les suivis démographiques doivent être associés à des études précises de l’habitat urbain et des contraintes associées pour mieux comprendre l’évolution des populations d’oiseaux en ville.
... Shrub cover could have different effects on richness depending on the focal taxa. Increasing shrub cover especially in highly urbanized matrix improved richness of imperilled insectivorous bird guild (Pellissier et al. 2012) but reduced bee richness by reducing their nesting resources (Banaszak-Cibicka et al. 2016).Exotic plant species constitute a large proportion of urban vegetation and have been shown to negatively (Khera et al. 2009) influence bird species diversity and in some cases elevated abundance of non-native birds (White et al. 2005;Daniels and Kirkpatrick 2006). In contrast, native vegetation and large old trees has been shown to improve bird species richness (Ferenc et al. 2014;Narango et al. 2017). ...
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Rapid urbanization is emerging as one of the leading threats to the biodiversity globally. But is especially a cause of concern for tropical countries which are urbanizing much faster and with relatively less urban planning than temperate ones. Urban green spaces are established to reduce the negative impacts of urbanization by conserving a large suite of species. Yet our knowledge on the significance of urban green spaces for supporting urban fauna and enhancing species richness is lacking for tropical countries such as India. We examined how landscape and local scale features of urban green spaces influence bird species richness, density, fine-foraging guild richness and composition during breeding and non-breeding season in Dehradun, India. We quantified landscape level variables in the 250 m buffer around 18 urban green spaces. We sampled vegetation and bird community during breeding and non-breeding season through 52 intensive sampling point spread across 18 urban green spaces. Size of the urban green space at landscape level and tree species richness at the local scale emerged as important predictors influencing bird species richness, density and richness of imperilled insectivorous guild across seasons. Urban green spaces within education institutions and offices experiencing less vegetation management supported higher bird species richness and density whereas city parks were species poor. Community composition was affected more strongly by built-up cover and barren area in the landscape matrix and also by tree species richness at the local scale within urban green spaces. City planners should focus on allocating green spaces within urban settings and expand the formal green spaces. Existing green spaces could be improved by augmenting compositional and structural heterogeneity of vegetation as well as conservation of large old native trees.
... While high densities of Rainbow Lorikeets and Musk Lorikeets were recorded in Melbourne in the autumn/winter of 2002 associated with intense eucalypt flowering (Fitzsimons et al. 2003;White et al. 2005), Little Lorikeets were found to be relatively uncommon in that particular study (and in subsequent studies, e.g. van Polanen Petel and Lill 2004;Platt and Lill 2006;Stanford and Lill 2008;Fitzsimons et al. 2011). ...
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Observations are presented of aggression between a pair of Little Lorikeets Glossopsitta pusilla and an Eastern Rosella Platycercus eximius at a nest hollow, and nesting activity by the Lorikeets in inner eastern Melbourne, Victoria. Aggression between these two species does not appear to have been previously reported, while the timing of the nesting activity (autumn) is considered unseasonable for Little Lorikeets.
... Considering the birds as targets, this approach can be useful in suggesting priority streets for planting trees. As many authors have found, wooded streets have a positive influence on avifauna: they can increase bird richness and diversity (Young et al. 2007), the community's functional aspects (Schütz and Schulze 2015) and the number of bird feeding guilds (White et al. 2005). These influences are stronger in urban areas with a predominance of native trees (Ikin et al. 2013). ...
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... Both frugivores/nectarivores and introduced species increased with these urban metrics, which may be due to an abundance of food resources associated with urban environments. Other studies have noted the suitability of urban habitats for frugivores/nectarivores due to an abundance of both native and exotic flowers and fruits (Souza et al., 2019), while introduced species have also been found to be particularly abundant in streetscapes in Australia (White et al., 2005) and in Puerto Rico (Ruiz-Jaén and Aide, 2006;Suarez-Rubio and Thomlinson, 2009), again attributed to the presence of exotic vegetation from residential landscaping. In contrast, the one granivore in this study was only found in sites with less than 40% urban cover, despite other studies suggesting favorable conditions in urban habitats for these birds (Chace and Walsh, 2006). ...
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Urbanisation is driving rapid declines in species richness and abundance worldwide, but the general implications for ecosystem function and services remain poorly understood. Here, we integrate global data on bird communities with comprehensive information on traits associated with ecological processes to show that assemblages in highly urbanised environments have substantially different functional composition and 20% less functional diversity on average than surrounding natural habitats. These changes occur without significant decreases in functional dissimilarity between species; instead, they are caused by a decrease in species richness and abundance evenness, leading to declines in functional redundancy. The reconfiguration and decline of native functional diversity in cities are not compensated by the presence of exotic species but are less severe under moderate levels of urbanisation. Thus, urbanisation has substantial negative impacts on functional diversity, potentially resulting in impaired provision of ecosystem services, but these impacts can be reduced by less intensive urbanisation practices.
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Anthropogenic land transformation, especially agriculture and urban development, are the leading causes of natural land cover loss and ultimate decline in environmental functionality and connectivity in KwaZulu-Natal Province, South Africa. However, recent developments in the form of housing estates with conservation and environmental management intentions (termed eco-estates) have increased. These eco-estates generally improve species and functional diversity in urban regions of coastal KwaZulu-Natal and improve connectivity for biodiversity between urban green spaces and existing natural landscapes. To provide the first comprehensive development and management guidelines for eco-estates, we reviewed and assessed research into the effects of eco-estate development on environmental functionality and connectivity using case studies from coastal KwaZulu-Natal. We suggest suitable regions for eco-estate establishment and provide detailed guidelines for ecoestate development, environmental rehabilitation and conservation, and eco-estate flora and fauna management. These guidelines will hopefully facilitate biodiversity conservation and improve current and future eco-estate management and, ultimately, the ecosystem health of coastal KwaZulu-Natal. They are applicable for ecoestate development and management in similar tropical and sub-tropical mixed land-use matrices.
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Civilization built around rivers directly affects riparian corridor structure and ecology. Degradation, pollution, and deterioration along riparian corridors in urban landscapes change species composition and biodiversity. Birds are one of the most vulnerable taxa to ecological changes. The main objective of our study was to spatially compare bird species richness, abundance, and community structure along the Asar River, an urban riparian corridor in Düzce, Turkey. We identified 63 bird species, comprising 6722 individuals, and classified them into one of three groups: generalist species (11 species), woodland species (40 species), and waterbird species (12 species). Bird species richness was positively related to vegetative cover and negatively to urbanization. Richness was low in the winter and was higher during spring and summer. Riparian Quality Index (RQI) scores (mean = 54.8 ± 33.7; max. = 97 and min. = 5) were relatively low for all sampling plots and was reduced by human activities (e.g., roads, farmland, settlement). The number of woodland bird species changed positively (r = 0.71) with RQI. The generalist bird species, adapted to urbanization, were more common around settlements and open areas. Human population and settlement around Asar River increased one-third and farmland and natural habitat decreased one-fifth during the last decade. The area has high potential for growth and increased urbanization, thus increasing the pressure on the natural areas. Activities that diminish the amount of tree cover in the riparian corridor should be avoided. Habitat restoration and rehabilitation will increase RQI values, which can be used as indicators for bird richness in urban landscapes and benefit avian diversity along the riparian corridor. The existing riparian corridor and any enhancements to the corridor will help conserve Düzce’s biodiversity in the future.
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The sight of chirping birds all around and their colorful plumage is a pleasure for humans. The birds are varied in their food choices and feeding habits and this study provides an insight to the varied food types and feeding habits of the different species of birds found very commonly in different suburbs and urban regions in India. The study has been performed by very detailed observational work on the commonly found species of garden birds in the suburb and foothills of Gurabandha forest. Majority of these birds were found to be omnivores, mostly insectivores and frugivorous which clearly explains the type of food resources available for these birds in this region. There is enough forest cover and varied flora that provides enough food and shelter to these wide range of avifauna in the foothills. In this study, about twenty-two species of birds have been identified and their food and feeding habits has been studied in details.
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Urban exploiters and adapters are often coalesced under a term of convenience as ‘urban tolerant’. This useful but simplistic characterisation masks a more nuanced interplay between and within assemblages of birds that are more or less well adapted to a range of urban habitats. Furthermore, cues are generally sought in behavioural ecology and physiology for the degree to which particular bird species are predisposed to urban living. The data in this paper are focused on two assemblages characterised as urban exploiters and suburban adapters from Melbourne, Australia. This study departs from the approach taken in many others of similar kind in that urban bird assemblages that form the basis of the work were identified at the landscape scale and from direct data analyses rather than indirect inference. Further, this paper employs a paired, partitioned analysis of exploiter and adapter preferences for points along the urban-rural gradient that seeks to decompose the overall trend into diagnosable parts for each assemblage. In the present paper I test the hypotheses that the distinct urban exploiter and suburban adapter assemblages within the broad urban tolerant grouping in Melbourne vary in their responses within the larger group to predictor variables, and that the most explanatory predictor variables vary between the two assemblages. In the end, habitat-of-origin better predicts degree of adaptation amongst urban tolerant birds.
Preprint
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Urban exploiters and adapters are often coalesced under a term of convenience as ‘urban tolerant’. This useful but simplistic characterisation masks a more nuanced interplay between and within assemblages of birds that are more or less well adapted to a range of urban habitats. Furthermore, cues are generally sought in behavioural ecology and physiology for the degree to which particular bird species are predisposed to urban living. The data in this paper are focused on two assemblages characterised as urban exploiters and suburban adapters from Melbourne, Australia. This study departs from the approach taken in many others of similar kind in that urban bird assemblages that form the basis of the work were identified at the landscape scale and from direct data analyses rather than indirect inference. Further, this paper employs a paired, partitioned analysis of exploiter and adapter preferences for points along the urban-rural gradient that seeks to decompose the overall trend into diagnosable parts for each assemblage. In the present paper I test the hypotheses that the distinct urban exploiter and suburban adapter assemblages within the broad urban tolerant grouping in Melbourne vary in their responses within the larger group to predictor variables, and that the most explanatory predictor variables vary between the two assemblages. In the end, habitat-of-origin better predicts degree of adaptation amongst urban tolerant birds.
Preprint
Full-text available
Urban exploiters and adapters are often coalesced under a term of convenience as ‘urban tolerant’. This useful but simplistic characterisation masks a more nuanced interplay between and within assemblages of birds that are more or less well adapted to a range of urban habitats. Furthermore, cues are generally sought in behavioural ecology and physiology for the degree to which particular bird species are predisposed to urban living. The data in this paper are focused on two assemblages characterised as urban exploiters and suburban adapters from Melbourne, Australia. This study departs from the approach taken in many others of similar kind in that urban bird assemblages that form the basis of the work were identified at the landscape scale and from direct data analyses rather than indirect inference. Further, this paper employs a paired, partitioned analysis of exploiter and adapter preferences for points along the urban-rural gradient that seeks to decompose the overall trend into diagnosable parts for each assemblage. In the present paper I test the hypotheses that the distinct urban exploiter and suburban adapter assemblages within the broad urban tolerant grouping in Melbourne vary in their responses within the larger group to predictor variables, and that the most explanatory predictor variables vary between the two assemblages. In the end, habitat-of-origin better predicts degree of adaptation amongst urban tolerant birds.
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Urbanization is a major cause of ecological degradation around the world, and human settlement in large cities is accelerating. New York City (NYC) is one of the oldest and most urbanized cities in North America, but still maintains 20% vegetation cover and substantial populations of some native wildlife. The white-footed mouse, Peromyscus leucopus , is a common resident of NYC’s forest fragments and an emerging model system for examining the evolutionary consequences of urbanization. In this study, we developed transcriptomic resources for urban P. leucopus to examine evolutionary changes in protein-coding regions for an exemplar ‘urban adapter’. We used Roche 454 GS FLX+ high throughput sequencing to derive transcriptomes from multiple tissues from individuals across both urban and rural populations. From these data, we identified 31,015 SNPs and several candidate genes potentially experiencing positive selection in urban populations of P. leucopus . These candidate genes are involved in xenobiotic metabolism, innate immune response, demethylation activity, and other important biological phenomena in novel urban environments. This study is the first to report candidate genes exhibiting signatures of directional selection in divergent urban ecosystems.
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The classification of plant species as native or exotic has ramifications for how they are treated within urban green space policy and practice. Green spaces are built or managed to fulfil a range of ecological and social functions, and decisions must be made about which plants to include to achieve these functions. There is growing literary and policy emphasis on native-only planting strategies, under the assumption that native species will deliver a greater range of biodiversity benefits. Yet, there remains a disconnection between theoretical debates on the definition or value of nativeness, and urban design practice. Using a systematic review, we examine the relationship between plant nativeness and animal biodiversity in urban areas. We argue that both the use and definition of native species involve value-laden decisions. The social roots of ‘native’ definitions have led to ambiguity in its use within the literature. Despite this ambiguity, we find that most studies show a positive influence of native plants on at least one measure of biodiversity, justifying their priority in urban plantings to support native animals. We conclude with considerations for the selection of plants for urban greening to promote native biodiversity: 1) the resources a plant provides are more important than its origin, but 2) when in doubt, ‘nativeness’ is a good surrogate of whether a plant will provide for local animals, and allows for the conservation of plants themselves; and 3) flexibility in scale of provenance allows for strategic responses to changing climates or competing objectives of urban design.
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Urban green spaces (UGS), such as parks and wooded streets, are open areas with vegetation that provide sustainability to urban areas. However, their role in conserving bird diversity in neotropical cities has scarcely been analyzed. The aim of this study was to analyze the variation of bird assemblages in non-wooded streets, wooded streets, and parks in Buenos Aires City, Argentina. We compared the taxonomic and functional diversity between these habitat types. We selected five non-wooded streets, five wooded streets, and five parks in the city. Bird surveys were performed in 100 m long and 50 m wide transects. We found that taxonomic diversity had the greatest value in the parks, followed by wooded streets, and then the non-wooded streets. Functional diversity was similar between habitats. The taxonomic and functional composition changed between habitats. Non-wooded streets were dominated by the Rock Dove (Columba livia) and the Eared Dove (Zenaida auriculata), whereas parks had the highest abundance of the Picazuro Pigeon (Patagioenas picazuro) and the Rufous-bellied Thrush (Turdus rufiventris). Non-wooded streets were dominated by omnivorous and granivorous species, whereas parks had a higher abundance of herbivorous and frugivorous species. The positive association between UGS and bird diversity highlights the role of UGS as biodiversity conservation sites in neotropical cities.
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Co-habiting with humans in an urban ecological space requires adequate variation in a species’ behavioural repertoire. The eco-ethology of many urban species have been shown to be modified due to human activities leading to urban adaptations. Dogs (Canis lupus familiaris) are the first species to have been domesticated and have a long evolutionary history of co-habitation with humans. In the last two decades, scientists have investigated various questions on dogs pertaining to its domestication. In fact, no other species belonging to the family Canidae has received such attention in the scientific world. Unfortunately, majority of the work was confined to pet dogs in the western countries. Pet dogs are the result of artificial breeding based on desirable traits and their activities are typically determined by their owners. Free-ranging dogs found in most of the developing countries, on the other hand, represent a naturally breeding population without direct human supervision. Studying free-ranging dogs can thus provide us with crucial insights on the ecology and evolution of dogs in greater detail. Close to 80% of the world’s dog population is free-ranging, yet scientific studies on them are almost non-existent. Scientists have realised the importance and need of studying these dogs very recently to address various facets of the much debated domestication event. Free-ranging dogs are a highly successful urban-adapted species living in all possible human habitats in the developing countries. The dog-human relationship is highly complex and possess multiple trajectories. For example, these dogs depend on human subsidized food, choose dens near human households, yet receive a range of negative stimuli from humans; mortality of these dogs is mostly influenced by humans. In this thesis, we tried to answer questions relating to the dog-human relationship on Indian streets. My thesis involved an interdisciplinary approach where behavioural, cognitive, and ecological aspects are discussed to shed light on the evolution of the dog-human relationship. We began the work by looking at the natural history of free-ranging dogs in India. We collected data on the abundance of dogs and the distribution of their potential food resources, across India. Moreover, we recorded the sex ratio, group size, and behaviours of dogs at different study locations. We characterized study areas with regard to human activity levels by estimating human flux or movement and categorised them into low, intermediate and high flux zones. Our findings clearly suggested varying distribution of dogs and their food resources across different microhabitats in India. While a direct effect of food resource was not found, human flux significantly predicted the distribution of dogs. Moreover, we found a strong impact of changing human flux on the abundance and behavioural activity of free-ranging dogs. In the next section, we investigated the intra-group dynamics of dogs from the perspective of long-debated dominance-rank relationships. We looked at the steepness and linearity of agonistic and formal dominance hierarchies of groups of dogs from intermediate and high human flux zones. Our study did not reveal any clear dominance hierarchy among the free-ranging dogs, either in the intermediate or high human flux zones. The overall frequencies of interactions between the group members were found to be quite low, with many unknown interactions between for several dyads. We also proposed the use of subtle behavioural cues to maintain hierarchy rather than showing frequent behavioural exchanges in dogs. Findings from the study further led us to test free-ranging dogs’ interactions with humans. We found that these dogs interact with humans more compared to their conspecifics. Interestingly, we noticed that dogs rarely initiated behaviours towards humans, while humans played the predominant role in initiating both positive and negative behaviours towards dogs. We concluded that humans are a predominant part of the interaction network of the Indian free-ranging dogs. This opened up a window of testing dogs’ physical and social cognitive abilities. We found that free-ranging dogs lack the ability to persist on physical cognitive tasks and are poor performers like pet dogs. A higher dependence on humans is thought to be a key factor restricting dogs from persisting on an unfamiliar task. Interestingly, free-ranging dogs, as scavengers, showed competence while solving a familiar task, though task difficulty remained a factor that could not be disentangled. A partial dependence on humans was assumed to be the outcome of their long-history of co-evolution which resulted in a reduced problem-solving capacity in dogs. Surprisingly, a role of social facilitation was observed which predicted improved performances in both familiar and unfamiliar tasks. Free-ranging dogs like any other urban species are typically found to be aversive towards making direct physical contact with unfamiliar humans. The sociability of dogs was found to correlate with human flux, suggesting a role of life experience in shaping the personalities of these dogs. Dogs were shown to understand different human social cues and respond accordingly. The dogs in groups were bolder while responding to threatening cues from humans than in the solitary condition. Using two studies, we showed their ability to understand human pointing gestures, both simple and complex. The behavioural states of the dogs were heavily found to influence their responses towards humans. Dogs were found to be anxious or fearful while encountering an unfamiliar human. Interestingly, we found a crucial role of positive socialization in the form of petting in modifying such behavioural states of dogs and further building a strong dog-human relationship. In summary, this thesis provides unprecedented inputs into the current understanding of the evolution of dog-human relationship. The findings are not only restricted to the scientific advancement but may also be helpful in mitigating the growing doghuman conflict on the streets in India, by enhancing an understanding of the dynamics of the relationship between the two species, that might enable better management strategies.
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Urbanization poses serious threats to biodiversity in many regions of the developing world. Understanding the factors that influence bird communities at the local and landscape level is important to guide urban planning efforts toward enhancing bird diversity. How bird species richness and diversity vary and the environmental factors that optimize their functional diversity in urban settlements remains poorly understood. We investigated the relationship between environmental characteristics and bird taxonomic and functional diversity across an urban settlement density gradient in Harare, Zimbabwe. Seventy-two transects were surveyed for bird species and environmental characteristics, and 6639 birds representing 94 species were recorded. Bird species richness and diversity declined from low to high settlement density sites, whereas bird functional diversity and abundance did not vary across the urban settlement density gradient. Characteristic species for low and high settlement density sites were Purple-crested Turaco (Tauraco porphyreolophus) and Pearl-breasted Swallow (Hirundo dimidiata), respectively. There were significant dissimilarities in bird species assemblages across the urban gradient. We demonstrated that the presence of water features and vegetation (presence of flowering plants and tree height) were the most significant environmental predictors of bird functional diversity. Loss in species richness across the urban settlement density gradient does not seem to be accompanied by significant declines in functional richness. The key message for urban planning here is that; despite the homogenization of urban environments and loss of bird species richness (Melles et al., 2003), broad ecosystem functionality may be maintained across the urban settlement density gradient.
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As with most cities throughout the world, the Western Australian city of Perth is beautified with rows of street trees. Here, the choice of trees tends to be dictated by their hardiness and ease of cultivation (e.g., Queensland Box Lophostemon confertus), their perceived beauty (e.g., Lemon Scented Gum Eucalyptus citriodora) and the affiliation with species from regions where many of the settlers originated (e.g., London Plane Tree Platanus acerifolia). Evidence indicates that the abundance and diversity of arthropods on a tree species is, to a large extent, a reflection of the tree in recent geological history ? the more recent the arrival, the less arthropods are likely to occur on it (Southwood 1960, 1961). From work with native eucalypt species, Recher et al. (1996) have found that arthropod density and diversity differs markedly between tree species within an ecosystem, and this phenomenon flows through to the insectivorous birds which forage on these trees. Those species with high levels of arthropods, such as Narrow-leaved Ironbark E. crebra in New South Wales are visited by pardalotes, thornbills and weebills to a much greater extent than the co-dominant Grey Box E. moluccana (Recher et al. 1994).
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1. The feeding guild is a useful tool for analysing community structure. Unfortunately, although there has been much work done on guilds of forest and woodland birds, there have been few studies in which differences between habitats have been assayed for consistency of guild structure. This can be done only by surveying replicate sites of each habitat type because this yields an indication of similarity between sites of the same class of habitat. If guild structure differs little between each replicate site, then one has confidence that that structure meaningfully characterizes the habitat type in question. 2. In this study, foraging information is used to produce a guild classification for birds of forests and woodlands of central Victoria, Australia. Four replicate sites of five forest and woodland classes were censused. 3. Guild structures in two habitat classes (open woodlands of the Goulburn River valley, and Gippsland manna gum Eucalyptus pryoriana woodlands) were distinct from both each other and also from those of three other habitat types (montane forests, foothill woodlands, and box-ironbark dominated forests). There was little differentiation between the latter three habitat types. 4. Much the same guild structure occurred in replicate sites of each habitat class, indicating that there is a systematic basis for guild structure that can be broadly related to habitat structure. In some habitats, maintenance of guild structure from replicate to replicate is mediated by similar arrays of species, whilst in other habitat types, there are significant differences in the actual species occupying guilds even though numbers of species in each guild are similar. Thus, use of replicate sites provides important additional information on how guilds are composed in different habitats.
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Lorikeet densities were measured across four habitat types in urban Melbourne. Musk Glossopsitta concinna and Rainbow Lorikeets Trichoglossus haematodus were shown to preferentially use established streetscapes with predominantly native vegetation. The high densities of Musk Lorikeets recorded possibly reflect a paucity of flowering in Victorian Box– Ironbark forests during the autumn/winter of 2002 and the availability of supplementary nectar resources in the urban environment. Future planting decisions in recently developed streetscapes will dictate the long-term resource potential for lorikeets and other nectarivores in urban Melbourne.
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The foraging behaviour of 40 species of birds in eucalypt woodland near Armidale is described. The foraging method, substrate, height and plant were noted for each foraging observation. Six guilds can be recognized on the basis of the substrate on which they forage. (1) Eleven species forage on the ground. This group includes two seed-eaters, and three insectivores that pounce on terrestrial invertebrates from low perches or the air. The remainder are gleaners of invertebrates. (2) Four species are bark-foragers. One is a trunk specialist, while the other three feed on upper branches, exfoliating bark and horizontal boughs respectively. (3) Foliage foragers make up the largest guild, with 13 species. Four species glean from both acacias and eucalypts. Three species mostly snatch insects from leaves whereas the rest glean from eucalypt leaves. This last group of species includes pardalotes and some honeyeaters, which feed on carbohydrate foods such as manna and honeydew as well as on arthropods. (4) There is single frugivore, specializing on mistletoe fruits. (5) The six aerial feeders include species that capture prey by hawking from a perch and others that continuously sweep through the air after insects. (6) Finally five nectarivores visit the flowers of eucalypts (three species) or mistletoe (two species) Several very similar pairs or groups of species were identified (pardalotes Pardalotus, honeyeaters Melithreptus, thornbills Acanthiza). These merit more detailed study; indeed several have already been investigated.
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Breeding bird communities in Sonoran Desert habitats show strong correlations between total bird density and an index of vegetation volume. We have suggested that this empirical relationship is due to responses of breeding birds to critical resources, for which vegetation volume is an accurate estimator. In 1987, we conducted a study in Tucson, Arizona, to determine how this empirical relationship is affected by the presence of exotic species of plants and birds, and other factors associated with urbanization. We supported five predictions of our resource-based hypothesis by examining patterns of bird density and diversity in 34 neighborhoods. Densities of territorial native bird species, as well as native species richness and overall species diversity, were strongly correlated with the vegetation volume of native plant species, and uncorrelated with volume of exotic plant species. Densities of exotic and nonterritorial native birds correlated with exotic vegetation volume, the factor which best estimated the distribution of roosting and nesting sites preferred by these species. Vegetation factors explained more of the variance in breeding bird density than did measures of housing density. We interpret these results as confirming our hypothesis that densities of breeding birds correlate strongest with factors associated with critical resources. In addition, these patterns suggest that native bird populations may be better retained in areas of urban development by landscaping with native plants in such a way as to retain predevelopment distributions of vegetation volume.
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We employed an island biogeographic approach to determine whether small fragments of the shrub habitats coastal sage scrub and chaparral, isolated by urbanization, are capable of supporting viable populations of native rodent species. The distribution of native rodents in 25 urban habitat fragments was assessed by live-trapping. Over half of the fragments surveyed (13 of 25) did not support populations of native rodents. Fragments supported fewer species than equivalently sized plots in large expanses of unfragmented habitat, and older fragments (fragments that had been isolated for a longer period of time) supported fewer species. Both results implied that local extinctions occurred in the fragments following insularization. Stepwise multiple polychotomous logistic regression was used to determine which biogeographic variables were the best predictors of species number across fragments. The area of shrub habitat in each fragment was the most significant predictor of species diversity; age of a fragment was also significant and was negatively correlated with species number, but the isolation distance of a fragment had no relationship to species diversity we found a negative relationship between extinction vulnerability of native rodent species and relative abundance: species that were more abundant in unfragmented habitat persisted in more habitat fragments. Random environmental and demographic fluctuations (island effects) and edge effects associated with fragmentation are proposed as causes of these local extinctions.
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The foraging ecology of eucalypt forest and woodland birds was studied on three 10 ha plots in southeastern Australia. Quantitative data were obtained for 41 species of which 31 were insectivorous, eight were nectar-feeders, and two were parrots that fed primarily on eucalypt seeds. Birds-of-prey, large omnivores and frugivores were uncommon. Insectivorous birds differed in foraging behaviour, the substrates on which they found prey, and foraging height. Nectar- feeders exploited a variety of carbohydrates including nectar, honeydew, lerp, manna and sap. Nectarivorous birds were separated by foraging behaviour, substrate, height and by the extent to which they used the different types of carbohydrates. Carbohydrates were also an important food resource for some insectivores. By understanding how birds exploit food resources within forest and woodland environments, the features of the environment which need to be conserved or manipulated to manage forest avifaunas can be identified. For example, in addition to the substrates such as foliage and bark, usually associated with the foraging of forest birds, carbohydrates and loose bark were identified as important resources for birds in eucalypt forests and woodlands. The broad importance of these two resources to the avifauna had not been previously appreciated, yet both may be sensitive to environmental changes associated with logging and other forest management practices which alter the composition or age-class structure of forests.
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A total of 8262 birds of 57 species was counted in a degraded public reserve and adjacent residential area during 61 paired transects in 1990. Most of the reserve was remnant wet sclerophyll forest (5 ha) and subtropical rainforest (0.4 ha), whereas a variety of mature native and introduced trees and shrubs were present in the 55-year-old suburb. Species evenness was similar in the habitats of the reserve and residental area but not species richness, number of individuals or composition of the avifauna. In all seasons, the reserve was richer in species but poorer in absolute numbers of birds. Thirteen native species were reserve specialists, six species (five introduced) were suburb specialists and 17 species showed only slight habitat preference. Excluding silvereyes, which showed little preference for either habitat, there were twice as many regularly occurring species that preferred to use the reserve rather than the residential area but only half the number of individuals. Nine specialist species are at risk of local extinction because their populations in the reserve are critically small [range: 80 (brown gerygone, Gerygone mouki) to 5 birds (eastern whipbird, Psophodes olivaceus)]. Seventeen species have become locally extinct since Europeans arrived in 1816. Conservation of the avifauna is discussed.
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Habitat use by birds in suburbs of Brisbane, Queensland was studied during winter, at sites with relatively similar habitat features near to (0.25-0.5km) and far from (2-3km) a eucalypt forest. Variation in other factors was restricted. Distance from native forest was found to have little influence on abundance of birds in suburban habitats. House sparrows and willie wagtails were relatively more abundant at the far sites. Most of the more common forest-dwelling species were not common in either near or far suburbs. There was little similarity in relative abundance of bird species between the forest and either the near or far suburbs. A similarity in species diversity and positive correlations in species abundance between near and far sites indicate that most species are either forest or suburb 'specialists'. Native birds were more selective in their choice of plant category than introduced birds, and had a high probability of using certain native and exotic plant species, and a lower probability of using others. Although generally more abundant, introduced birds did not have a high probability of using any plant genus or type. Birds in the area studied are probably altering their patterns of habitat use in response to changes in food availability.
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Relationships between species composition of breeding birds and area were investigated in 43 urban woods, ranging from 0.15 to 356ha from mid-May to late June in 1992 and 1993. Bird communities were surveyed by line transect census. Forty-one bird species were recorded, and the species composition changed and some species were added or omitted as the area increased. On the whole, area of the urban woods was a good indicator of species richness, S=4.76A0.21 (S: species, A: area in hectare) on the area of urban forests. Area is also correlated with number of species of each guild classified according to nesting sites, foraging sites and migration habits, respectively. The numbers of species nesting or foraging in the canopy and residents was higher regardless of area. The number of species using bush was most sensitive to area. On the other hand, hole-nesting birds were most insensitive. We suggest some management plans of bird conservation in urban woods in Seoul.
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A computational method to automatize some aspects of fracture analysis is presented. The method is based on the application of digital processing techniques to digitized bidimensional images of fractures, in order to obtain rugosity parameters based on fracture profiles. Also, the fractal dimension of the considered fractures are calculated, not in its classical form, as proposed by Mandelbrot, but in a modified form, due to Underwood and Banerji, more appropriated to fractography. The results were condensed in user-friendly program.
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AimUrbanization can lead to uniformity in urban bird communities, and the general biogeographical patterns found in natural communities may not be found in urban ones. Thus, it is important to know if urbanization might be seen as contributing to a general pattern that modifies the biogeographical processes of wildlife communities.LocationWe studied differences in suburban bird assemblages in France and Finland. Birds in each town included in the study were surveyed using 30 ha suburban study plots located within single-family housing area and apartment block area.Methods The wintering birds were surveyed using a single-visit study plot method in January and February 1999. The level of urbanization was measured according to the general structure of the habitat by using the town maps and field notes. In addition, we counted active winter feeding stations during bird surveys.ResultsThe average number of species was higher in France than in Finland, both in single-family house areas and in apartment block areas. The most abundant bird species occurred in most of the study sites. The urbanization level affected bird community composition more in northern Finland than in France. In Finland, the number of wintering species and their total biomass were higher in single-house areas than in more urbanized areas. The total density and biomass of birds were higher in France than in Finland in areas of apartment blocks, but not in the areas of single-houses. Urbanization level affected the total bird density only in France, being higher in areas of apartment blocks. In Finland, the total biomass of birds was higher in the single-family house areas than in the areas of apartment blocks. Most of the bird species were more abundant in France than in Finland. The habitat factors associated with the bird community variables in France and in Finland differed from one another. Feeding tables increased the species richness and the abundance of birds in Finland.Conclusions The species decrease between France and Finland was mainly because of the large proportion of species in France that are migratory in northern Finland. The abundance of urban birds did not necessarily decrease northwards. Intensive winter feeding in northern latitudes may help birds to overcome natural range limitations. Our results differed from results obtained when studying town centres and they highlight the complexity of the urbanization process across a geographical gradient.
Article
Summary • The species diversity of adjacent landscapes influences the conservation or restoration of several animal groups in urban areas, but the effect on birds is unclear. To address this question, we compared bird species richness (BSR) and community composition between periurban (area surrounding the town) and urban (suburban and centre areas) landscapes across three spatial scales. • At a large biogeographical scale (temperate and boreal climatic zone), relationships between the BSR of urban areas and their surrounding landscapes were examined in a meta-analysis of 18 published studies. In general, BSR was negatively correlated with latitude and urbanization. The BSR of suburban and centre landscapes correlated positively with the BSR of periurban landscapes. However, latitudinal effects were also involved, as BSR in urban and periurban landscapes declined as town latitude increased. Similarity indices were low (50%) between periurban and centre bird communities. • At a regional scale, we assessed winter bird data from several towns within three regions of temperate and boreal countries (western France, northern Finland and eastern Canada). The type of periurban landscape, number of inhabitants and town diameter did not affect BSR. BSR was similar between the cities of a given biogeographical area. Bird communities were more similar between similar habitat types of different cities than between different habitats of the same city. • At a local scale, we tested the influence of proximity to the periurban landscape on BSR in parks of western French towns of different size. Neither BSR nor community similarity changed in relation to the distance of the park from the periurban landscape. • Guild composition according to diet and feeding habitat did not vary between urban and periurban locations at regional or local scales. • We conclude that, at regional and local scales, urban bird communities are independent of the bird diversity of adjacent landscapes, and that local features are more important than surrounding landscapes in determining BSR. Whatever the biodiversity quality of the periurban landscape, site-specific actions such as shrub and tree planting, water restoration and increasing vegetation diversity can change bird diversity in towns and improve the quality of human–wildlife contacts.
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A large database collated by bird watchers was analysed to determine whether birds living in the urban habitats of Sydney, Australia could be characterised as a discrete community differing from those occupying a variety of nearby native habitats. Standardised surveys at fixed distances from nine remnants of one native habitat (woodland/scrub on Hawkesbury sandstone) were then conducted to determine whether size of, and distance to, remnants of native habitat influenced the composition of the surrounding suburban bird community. Non-metric multidimensional scaling did not separate the bird community of urban parks and gardens from those occupying residential areas. However, analysis of similarity showed that these communities were significantly different from the bird communities of each of the native habitats. Suburban habitats could be differentiated by the prevalence of exotic species as well as parrots, large honeyeaters, and large birds incorporating vertebrate foods in their diet, and a relative rarity of small insectivores and honeyeaters. Nearby remnant vegetation had little effect on the bird community inhabiting suburban areas. No significant effects of remnant size or remnant proximity were detected for species richness, individual abundance or community composition. These results suggest that there is little overlap in use of urban and remnant habitats by the majority of species and that in order to increase bird diversity, urban habitats must provide a fuller complement of ecological requirements.
Article
This study intends to assess the influence of fragment age, size and isolation (from the regional species pool) on bird community composition patterns in urban parks in Madrid, and the role of local and regional factors on community structure. Park age was a good indicator of habitat complexity. Park age and area accounted for 62% of the variability in species richness, but two measures of isolation from the regional species pool were not included as significant factors. Species composition in urban parks showed a high degree of nestedness, which was associated with park age and area, but not with two measures of isolation from the regional species pool. The degree of nestedness increased with park age; the distribution of species varying from nested in old and mature parks to random in young parks. The incidence (% of species occurrence in parks) in young parks was correlated with regional densities, whereas in mature and old parks the incidence was correlated with local densities. In this urban landscape, species composition appears to be regulated by local factors (particularly in mature and old parks), such that species accumulate in an orderly (not random) fashion in relation to park age and area. Regional influences seem to be more pronounced only in young parks, which are mainly colonized by species from the regional species pool.
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Using chemical knockdown procedures, canopy arthropod communities on eucalypts (Eucalyptus spp.) were found to be extraordinarily rich in species. Four seasonal samples from four species of eucalypts, two in eastern Australia and two in Western Australia, yielded 976 species of canopy arthropods from the eastern site and 683 species from the west. The richest and most abundant faunas occurred on the site with the greatest soil fertility and on the tree species with highest levels of foliage nutrients (i.e. nitrogen and phosphorous). High nutrient concentrations are taken as a measure of overall productivity. Seasonal and annual differences in arthropod abundances, biomass, and species richness are correlated with temporal changes in rainfall affecting tree phenological events (e.g. growth of new leaves) and productivity. Species of insectivorous birds that are dependent on energy-rich source carbohydrates (e.g. lerp, manna) select between plant species as foraging substrates on the basis of the kinds of arthropods available and their abundance on each kind of plant.
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The association of biodiversity and urban ecosystems has usually concerned the impact of urbanization on biodiversity. However, biodiversity concepts can easily be applied to the urban ecosystem itself. As more and more people live in cities, restoration, preservation and enhancement of biodiversity in urban areas become important. Concepts related to biodiversity management such as scale, hierarchy, species identity, species values, fragmentation, global approaches can be used to manage urban biodiversity. Application of these concepts in such artificial ecosystems may yield important insights for the management of natural ecosystems. Birds are highly visible and quite sensitive to changes in habitat structure and composition. Bird species richness in urban ecosystems is influenced both by local and landscape characteristics and a multi-scale approach is essential to its proper management. People–wildlife conflicts are an integral component of wildlife management in urban ecosystems and must be addressed. Enhancement of biodiversity in urban ecosystems can have a positive impact on the quality of life and education of urban dwellers and thus facilitate the preservation of biodiversity in natural ecosystems.
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We compared the breeding bird population and vegetation structure of 201 randomly selected 1 ha plots in 49 urban parks in Montreal, 15 years apart (in 1979–1981 and 1994). The constancy of 17 bird species increased significantly, while that of four others decreased. Increased large-tree cover and a reduction in shrub cover do not explain more than a small proportion of this variation in species constancy. We contend that the installation of bird feeder stations in and around parks goes a long way toward explaining these changes, although the recent arrival in Quebec of the House Finch (Carpodacus mexicanus) and the Northern Cardinal (Cardinalis cardinalis) has definitely played a major role in the changes of the bird assemblage.
Article
The Puente-Chino Hills, extending west into the highly urbanized Los Angeles Basin, represent one of the largest expanses of lowland habitats in the region. During spring and early summer of 1997 and 1998, birds and vegetation surveys were conducted to clarify the influence of geographical position in the distribution of birds in the hills. Using logistic regression, the inclusion of longitudinal position as a variable is shown to make a statistically significant contribution to bird species presence beyond that of habitat alone for 12 of the 49 most commonly detected species. Species more common than would be expected based on habitat in the east were typical of grassland and open habitats, whereas those more common in the west were characteristic of tall scrub or urban habitats. Thus, species’ distributions in the hills are likely influenced by landscape-scale vegetation patterns and by the aggregate amount of urbanized areas in the west. This emphasizes the importance of using geographical position as a variable when analyzing patterns in bird distribution and siting conservation areas.