scholarly journals Impact of Urbanization to an Island and the Continent: Species Turnover and Nestedness in Neotropical Bird Assemblages

2021 ◽  
Vol 9 ◽  
Author(s):  
Sabina A. Caula ◽  
Virginia Sanz D'Angelo

Islands are well-known as particular and vulnerable ecosystems with evolutionary histories, environmental characteristics, and original communities different from those of continents. On the contrary, urban environments are recent, artificial, and structurally similar among distant regions. To assess the relative importance of regional and local processes on urban biota, we chose two urban environments, i.e., one on the mainland and another on an island in the same ecoregion. We asked whether the urbanization process affects the avian biodiversity of the ISLAND in the same way as in the continent. We defined an urban gradient with three levels of building density, namely, patches of native vegetation (remnant woodlands in the urban matrix), medium density urbanized areas that maintain vegetation along the streets and gardens, and residential areas with less vegetation cover and higher building density. In each geographical locality, we selected three sites (replicates) for each level of the urban gradient and did bird surveys. We found two times as many species in the urban landscape of the continent (69) as on the island (35), with the analogous richness decrease along the gradient in both regions. Species similarity was higher between urbanized sites of both regions compared with the similarity between woodlands and urbanized sites, showing that urban matrix filters similar species of each pool regionally. Individual species responded to urban structure in different ways. We found 32% of bird species were urban exploiters, 48% urban tolerant, and 20% urban avoiders in both regions. However, some species showed different frequencies of occurrence on the island and the continent. Species turnover contributed more than richness differences to species dissimilarity along the urban gradient on the continent. Contrarily, the nestedness component (i.e., species being a strict subset of the species at a richer site) was higher on the island. We concluded that the negative impact of highly urbanized areas on birds was stronger on the island than on the continent. Our results may help to assess the implications of beta-diversity loss, especially on islands.

2017 ◽  
Vol 65 (2) ◽  
Author(s):  
Solange Mendes ◽  
Víctor J. Colino-Rabanal ◽  
Salvador J. Peris

Anthropogenic noise in urban environments is a major challenge for those species that depend on the transmission of acoustic signals to communicate. To avoid being masked by background noise, some bird species are able to make adjustments in their songs. Studies on vocal adjustment for tropical birds are still scarce and are of interest since both the urban structure and the vegetation associated with urban habitats differ significantly with respect to the cities of temperate climates. In this research we studied the changes in the song parameters of the pale-breasted thrush (Turdus leucomelas) in an urban environment of the metropolitan area of Belém (Brazil). To this end, bird songs were recorded and ambient noise was measured between September and November 2008, in three different acoustic environments (urban, suburban and rural) along an urban gradient. The songs of 12 individuals per area were selected (a total of 36). Possible differences between song parameters were analyzed by ANOVAs. To assess the noise impact on bird song, we only considered the spectrum of environmental noise within the range of vocalizations of the species. In general, birds of urban habitats presented songs with higher maximum frequencies and with a wider range of notes, than their counterparts in suburban and rural areas. The differences were more pronounced in relation to rural areas. No differences in the minimum frequencies, the concentration of energy, or the average duration of the notes were found. These results differ from other studies and could possibly indicate variations in the way birds try to succeed in habitats with high ambient noise. It is necessary further exploration on the role of these changes in the effective improvement of intra-specific communication for the species in such environments.


2017 ◽  
Vol 168 (2) ◽  
pp. 59-66
Author(s):  
Pierre Mollet ◽  
René Hardegger ◽  
Res Altwegg ◽  
Pius Korner ◽  
Simon Birrer

Breeding bird fauna in a coniferous forest in the northern Prealps after storm Lothar In a 70-hectare large coniferous forest located on the northern edge of the Alps in central Switzerland, Canton of Obwalden, at an altitude of 1260 to 1550 metres above sea level, we surveyed the local breeding bird fauna in 2002 and 2013 by means of point counts as well as additional area searches for rare species. In December 1999, hurricane Lothar caused two large windthrow areas and several smaller areas with scattered throws in the survey range. We found a total of 48 breeding bird species, which is a very diverse species composition for a mountain forest. In the eleven years between surveys, a decline in distribution or abundance was recorded for four species, while seven species showed an increase; a further four species showed no change. For the remaining species, the data sets were too small to reliably estimate changes. A comparison with forest structure data provided by the Swiss Federal Institute of Forest, Snow and Landscape Research WSL revealed that for five bird species, the changes in distribution or abundance could be explained at least partially by forest succession. In order to obtain realistic distribution and abundance values in this kind of breeding bird survey, it is essential to collect large enough samples and to consider the detection probability of each individual species using appropriate statistical methods.


2008 ◽  
Vol 32 (3) ◽  
pp. 111-119 ◽  
Author(s):  
Brandon Sladek ◽  
L. Burger ◽  
Ian Munn

Abstract Former agricultural lands converted to pine (Pinus spp.) plantations in the Conservation Reserve Program (CRP) have potential to provide early successional (ES) habitat for many regionally declining pine/grassland and shrub-successional bird species if actively managed with appropriate disturbance regimes. One such regime is use of the selective herbicide Imazapyr (Arsenal Applicators Concentrate) and prescribed burning, which is permitted on CRP lands and cost share payments are available. This study quantified combined effects of Imazapyr and prescribed fire on the breeding season avian community characteristics and pine volume growth in thinned, midrotation afforested loblolly pine (Pinus taedaL.) plantations in Mississippi. Herbicide treatments were applied in fall of 2002 and winter burns were conducted during winter and early spring of 2002–2003. ES bird species richness was significantly greater in the treated plots compared with controls for both 2003 and 2004. Ten individual species exhibited treatment effects. These responses by ES bird species indicate that midrotation CRPplantations can provide needed ES habitat if treated with appropriate disturbance regimes.


2017 ◽  
Vol 22 (3) ◽  
pp. 253-274
Author(s):  
Konstantinos Kepaptsoglou ◽  
Eleni Vlahogianni ◽  
Nikolaos Giannoulis ◽  
Aristeidis G. Karlaftis

Light rail transit systems (LRTs) are attractive options for modern communities as they offer high quality, sustainable public transportation services. However, investment costs often may make their application for medium-sized cities prohibitive, particularly if no significant social benefits are achieved. Guided light transit (GLT) has been introduced in the recent years, as a lower cost alternative to LRT, with the additional advantage of being suitable for urban environments with space limitations. In this study, a systematic comparison of LRT and GLT is offered, in the context of a mid-size city in Greece. Results indicate that high investment costs, coupled with low ridership can have a negative impact to the introduction of LRT in a medium-sized city. However, under certain conditions, GLT may be a viable alternative, while its nature and characteristics are not that different to those of LRT.


Biologija ◽  
2020 ◽  
Vol 66 (3) ◽  
Author(s):  
Grzegorz Kopij

A simplified version of the territory mapping method was used. Four counts were conducted in a fragment of the city of Wrocław in the spring and early summer 2010. Two main urban habitats were distinguished: a densely built-up area with block buildings and a residential area with flat houses. In total, 44 bird species were recorded as breeding in the whole study area. Five species nested in a density higher than 10 pairs per 100 ha each: Columba palumbus, Pica pica, Streptopelia decaocto, Sylvia atricapilla, and Turdus merula. Whereas in the densely built-up areas Columba palumbus and Streptopelia decaocto were equally common, in the residential area Streptopelia decaocto was almost three times more common than Columba palumbus. Pica pica was about three times more common than Corvus cornix both in the builtup areas and in the residential areas. Although densely built-up areas and residential areas have a similar species composition, many species breed in different densities. This is probably due to a different structure of vegetation. While tall trees are relatively common and shrubs rare in the densely built-up areas, the reverse situation prevails in residential areas.


2021 ◽  
Vol 2 (3) ◽  
pp. 1-4
Author(s):  
Maria Cecília Barbosa de Toledo

Green urban areas such as parks, squares, gardens, and forest fragments present a large diversity of uses and conservation objectives. These spaces provide resources for many species of birds that are confronted with the necessity of living in proximity to humans. It is assumed that bird species that acquire resources in urban environments live in a constant state of fear to guarantee survival and reproduction. In this context, the objective of this study was to evaluate the tolerance of birds with respect to human presence in two distinct conditions, rural areas (low level of human presence) and urban areas (high level of human presence). The fieldwork was conducted in a city in the Southeast region of Brazil, and the methodology used the alert distance and flight initiation measurements based on the approach of an observer to the individual bird being focused. Our results suggest that individuals observed in urban areas rely on shorter alert and escape distances, especially males, adults, and birds that forage in interspecific flocks. We discuss the challenges and strategies with respect to escape characteristics of urban birds, with special focus on the economic escape theory. In general, our results support those from studies conducted in other urban areas in different biogeographic regions, and they will aid in comprehending the impacts caused by the increase in urban areas around the world.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sebastian Steibl ◽  
Christian Laforsch

Abstract Coastal ecosystems suffer substantially from the worldwide population growth and its increasing land demands. A common approach to investigate anthropogenic disturbance in coastal ecosystems is to compare urbanized areas with unaffected control sites. However, the question remains whether different types of anthropogenic disturbance that are elements of an urbanized area have the same impact on beach ecosystems. By investigating small islands that are utilized for tourism, inhabited by the local population, or remained completely uninhabited, we disentangled different anthropogenic disturbances and analysed their impacts on hermit crabs as indicator species. We observed a negative impact on abundance on tourist islands and a negative impact on body size on local islands. In comparison to the uninhabited reference, both disturbances had an overall negative impact. As both forms of disturbance also impacted the underlying food resource and habitat availability differently, we propose that the findings from our study approach are valid for most obligate beach species in the same system. This demonstrates that in urbanized areas, the coastal ecosystem is not always impacted identically, which emphasizes the importance of considering the particular type of anthropogenic disturbance when planning conservation action in urbanized areas.


1998 ◽  
Vol 4 (4) ◽  
pp. 296 ◽  
Author(s):  
M. C. Calver ◽  
J. Dell

Sixteen mammal species and 22 bird species whose distributions extended into southwestern Australian forests before European settlement have been listed as threatened at some time in Commonwealth legislation, State legislation, or action plans of Environment Australia or its predecessors. Confident assessment of the causes of conservation status is hampered by poor base-line data, few studies of putative impacts and a preponderance of circumstantial or anecdotal rather than experimental evidence. However, introduced foxes were Implicated In the current conservation status of 62% of the mammal species recognized, while 44% of them were negatively impacted by feral cats, 44% by agricultural clearing and 44% by changed fire regimes. Forestry practices were impllcated in the conservation status of only one mammal species. For the bird species recognized, changed fire regimes had the greatest negative impact (45% affected), agricultural clearing affected 41%, draining of wetlands affected 32% and grazing by livestock affected 22%. Forestry practices were not directly implicated in the conservation status of any bird species. While these results suggest that forestry has had minimal direct impact on the mammals and birds of the forests, the conclusion should be treated cautiously because of the poor data. While awaiting a rigorous evaluation, we argue for a strong precautionary approach to forestry in the region. With proper forest management and sound sylvicultural [sic] treatment there is no reason why there should not be built up on the wreckage of the once splendid forests of Western Australia tended forests which will yield for all time 100 cubic feet of timber per acre per year. Lane-Poole (1920). There are many reasons why Australian environmentalists would like to end logging in native forests. The preservation of wilderness, aesthetics, an almost religious identification with old growth forests and the conservation of forest wildlife figure importantly in environmental efforts to restrict logging. Wilderness and a personal identification with trees and undisturbed forests are fundamentally incompatible with logging. Recher (1996).


Atmosphere ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 63 ◽  
Author(s):  
Tobias Gronemeier ◽  
Matthias Sühring

Courtyards are an omnipresent feature within the urban environment. Residents often use courtyards as recreation areas, which makes them crucial for the physical and psychological comfort of the urban population. However, considering that courtyards represent enclosed cavities, they are often poorly ventilated spaces and pollutants from neighboring traffic, once entrained, can pose a serious threat to human health. Here, we studied the effects of lateral openings on courtyard pollution and ventilation. Therefore, we performed a set of large-eddy simulations for idealized urban environments with different courtyard configurations. While pollutant concentration and ventilation are barely modified by lateral openings for wide courtyards, lateral openings have a significant effect on the mean concentration, the number of high-concentration events and the ventilation within narrower and deeper courtyards. The impacts of lateral openings on air quality within courtyards strongly depend on their orientation with respect to the flow direction, as well as on the upstream flow conditions and upstream building configuration. We show that lateral openings, in most cases, have a negative impact on air quality; nevertheless, we also present configurations where lateral openings positively impact the air quality within courtyards. These outcomes may certainly contribute to improve future urban planning in terms of health protection.


2020 ◽  
Vol 8 (12) ◽  
pp. 2037
Author(s):  
Aryse Martins Melo ◽  
David A. Stevens ◽  
Lisa A. Tell ◽  
Cristina Veríssimo ◽  
Raquel Sabino ◽  
...  

The One Health context considers health based on three pillars: humans, animals, and environment. This approach is a strong ally in the surveillance of infectious diseases and in the development of prevention strategies. Aspergillus spp. are fungi that fit substantially in this context, in view of their ubiquity, as well as their importance as plant pathogens, and potentially fatal pathogens for, particularly, humans and avian species. In addition, the emergence of azole resistance, mainly in Aspergillus fumigatus sensu stricto, and the proven role of fungicides widely used on crops, reinforces the need for a multidisciplinary approach to this problem. Avian species are involved in short and long distance travel between different types of landscapes, such as agricultural fields, natural environments and urban environments. Thus, birds can play an important role in the dispersion of Aspergillus, and of special concern, azole-resistant strains. In addition, some bird species are particularly susceptible to aspergillosis. Therefore, avian aspergillosis could be considered as an environmental health indicator. In this review, aspergillosis in humans and birds will be discussed, with focus on the presence of Aspergillus in the environment. We will relate these issues with the emergence of azole resistance on Aspergillus. These topics will be therefore considered and reviewed from the “One Health” perspective.


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