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Journal ArticleDOI

Modification of the third phase in the framework for vertebrate species persistence in urban mosaic environments

TL;DR: This paper reviewed case studies of vertebrate species' responses to urbanisation in KwaZulu-Natal, South Africa, to determine trends and presented a novel modification to the final of three phases of the framework described by Evans et al. (2010).
Abstract: Urbanisation is rapidly transforming natural landscapes with consequences for biodiversity. Little is documented on the response of African wildlife to urbanisation. We reviewed case studies of vertebrate species' responses to urbanisation in KwaZulu-Natal, South Africa to determine trends. Connected habitat mosaics of natural and anthropogenic green spaces are critical for urban wildlife persistence. We present a novel modification to the final of three phases of the framework described by Evans et al. (2010), which documents this sequence for vertebrate species persistence, based on the perspective of our research. Species in suburbia exhibit an initial phase where behavioural and ecological flexibility, life-history traits and phenotypic plasticity either contribute to their success, or they stay at low numbers. Where successful, the next phase is a rapid increase in populations and distribution; anthropogenic food resources and alternate breeding sites are effectively exploited. The modified third phase either continues to spread, plateau or decline.
Citations
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Journal ArticleDOI
30 Apr 2021-Ostrich
TL;DR: In Africa, increasing human populations and anthropogenic land-use change are generally affecting diversity negatively as mentioned in this paper, but especially in Africa, especially in Sub-Saharan Africa, a large number of people are migrating to the region.
Abstract: Globally, but especially in Africa, increasing human populations and anthropogenic land-use change are generally affecting diversity negatively. Urban environments in southern Africa typically comp...

14 citations

Journal ArticleDOI
TL;DR: In this article, the authors provide the first comprehensive development and management guidelines for eco-estates, reviewed and assessed research into the effects of eco-estate development on environmental functionality and connectivity using case studies from coastal KwaZulu-Natal.

4 citations

Journal ArticleDOI
TL;DR: In this paper , a meta-analysis was conducted to quantify the effects of urban environments on three components of trophic ecology in predators: dietary species richness, dietary evenness and stable isotopic ratios (IRs).
Abstract: Predation is a fundamental ecological process that shapes communities and drives evolutionary dynamics. As the world rapidly urbanizes, it is critical to understand how human perturbations alter predation and meat consumption across taxa. We conducted a meta-analysis to quantify the effects of urban environments on three components of trophic ecology in predators: dietary species richness, dietary evenness and stable isotopic ratios (IRs) (δ13C and δ15N IR). We evaluated whether the intensity of anthropogenic pressure, using the human footprint index (HFI), explained variation in effect sizes of dietary attributes using a meta-regression. We calculated Hedges’ g effect sizes from 44 studies including 11 986 samples across 40 predatory species in 39 cities globally. The direction and magnitude of effect sizes varied among predator taxa with reptilian diets exhibiting the most sensitivity to urbanization. Effect sizes revealed that predators in cities had comparable diet richness, evenness and nitrogen ratios, though carbon IRs were more enriched in cities. We found that neither the 1993 nor 2009 HFI editions explained effect size variation. Our study provides, to our knowledge, the first assessment of how urbanization has perturbed predator–prey interactions for multiple taxa at a global scale. We conclude that the functional role of predators is conserved in cities and urbanization does not inherently relax predation, despite diets broadening to include anthropogenic food sources such as sugar, wheat and corn.

3 citations

Journal ArticleDOI
TL;DR: In this article , a camera trap survey of front and back yards for 65 residential properties in the City of Mandurah, Western Australia was carried out to identify key features associated with the activity of a local endemic bandicoot species, the Isoodon fusciventer.

2 citations

Journal ArticleDOI
TL;DR: The authors conducted presence-only surveys at 52 locations between July 2019 and December 2020 to assess the presence of Spotted Thick-Knee and their interactions with humans in the fragmented natural and human-modified landscape of Pietermaritzburg, KwaZulu-Natal.
Abstract: Urbanisation has increasingly encroached on numerous bird species' natural habitats, generally negatively affecting their persistence. Furthermore, increased human-wildlife interactions may benefit or be detrimental to the long term persistence of these species. The Spotted Thick-knee (Burhinus capensis), a ground-nesting species, persists in some mosaic urban landscapes in South Africa. We, therefore, assessed the presence of Spotted Thick-knees and their interactions with humans in the fragmented natural and human-modified landscape of Pietermaritzburg, KwaZulu-Natal. We conducted presence-only surveys at 52 locations between July 2019 and December 2020. ‘Presence’ locations for Spotted Thick-knee were identified via active surveying and public participation. Newspaper articles were distributed in June 2019, requesting information on Spotted Thick-knee sightings. Questionnaires were also sent to respondents to collect qualitative information regarding their perceptions and observations of this species in Pietermaritzburg. We established that the presence of Spotted Thick-knee's at known locations was not random. They were present at 30 out of 52 sites for 75% of this study's duration. Fewer sites had Spotted Thick-knees present during non-breeding months than breeding months. Respondents' feedback highlighted the pressures associated with Spotted Thick-knees persistence in human-modified mosaic landscapes, particularly predation and disturbance by domestic pets. Our study highlights that some ground-nesting birds, such as Spotted Thick-knees, persist in mosaic urban landscapes, despite the anthropogenic pressures. This study highlights the need to address the paucity of studies on ground-nesting birds in mosaic urban landscapes to determine general trends.

1 citations

References
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Journal ArticleDOI
01 Sep 1994-Nature
TL;DR: A model is described that explains multispecies coexistence in patchy habitats and which predicts that their abundance may be fleeting, a future ecological cost of current habitat destruction.
Abstract: HABITAT destruction is the major cause of species extinctions1–3. Dominant species often are considered to be free of this threat because they are abundant in the undisturbed fragments that remain after destruction. Here we describe a model that explains multispecies coexistence in patchy habitats4 and which predicts that their abundance may be fleeting. Even moderate habitat destruction is predicted to cause time-delayed but deterministic extinction of the dominant competitor in remnant patches. Further species are predicted to become extinct, in order from the best to the poorest competitors, as habitat destruction increases. More-over, the more fragmented a habitat already is, the greater is the number of extinctions caused by added destruction. Because such extinctions occur generations after fragmentation, they represent a debt—a future ecological cost of current habitat destruction.

2,507 citations

Journal ArticleDOI
TL;DR: In this paper, the authors compile the most recent information on urban impacts on avian populations and communities and identify the processes that underlie the patterns of population and community level responses, but several areas of have been identified as being important.

1,397 citations

Journal ArticleDOI
TL;DR: The results show that patch area and corridors have the strongest positive effects on biodiversity, complemented by vegetation structure, and local, biotic and management habitat variables were significantly more important than landscape, abiotic or design variables.
Abstract: Understanding varying levels of biodiversity within cities is pivotal to protect it in the face of global urbanisation. In the early stages of urban ecology studies on intra-urban biodiversity focused on the urban–rural gradient, representing a broad generalisation of features of the urban landscape. Increasingly, studies classify the urban landscape in more detail, quantifying separately the effects of individual urban features on biodiversity levels. However, while separate factors influencing biodiversity variation among cities worldwide have recently been analysed, a global analysis on the factors influencing biodiversity levels within cities is still lacking. We here present the first meta-analysis on intra-urban biodiversity variation across a large variety of taxonomic groups of 75 cities worldwide. Our results show that patch area and corridors have the strongest positive effects on biodiversity, complemented by vegetation structure. Local, biotic and management habitat variables were significantly more important than landscape, abiotic or design variables. Large sites greater than 50 ha are necessary to prevent a rapid loss of area-sensitive species. This indicates that, despite positive impacts of biodiversity-friendly management, increasing the area of habitat patches and creating a network of corridors is the most important strategy to maintain high levels of urban biodiversity.

670 citations

Journal ArticleDOI
31 May 2017-Nature
TL;DR: Proactive international efforts to increase crop yields, minimize land clearing and habitat fragmentation, and protect natural lands could increase food security in developing nations and preserve much of Earth's remaining biodiversity.
Abstract: Tens of thousands of species are threatened with extinction as a result of human activities. Here we explore how the extinction risks of terrestrial mammals and birds might change in the next 50 years. Future population growth and economic development are forecasted to impose unprecedented levels of extinction risk on many more species worldwide, especially the large mammals of tropical Africa, Asia and South America. Yet these threats are not inevitable. Proactive international efforts to increase crop yields, minimize land clearing and habitat fragmentation, and protect natural lands could increase food security in developing nations and preserve much of Earth's remaining biodiversity.

647 citations

Journal ArticleDOI
TL;DR: This paper reviewed 300 papers investigating urbanization gradients that were published in peer-reviewed journals between 1990 and 2007 and found that Sixty-three percent of the papers investigated the distribution of organisms along urbanization gradient.
Abstract: Over the past decade, the urban–rural gradient approach has been effectively used to study the ecology of cities and towns around the world. These studies have focused on understanding the distribution of plants and animals as well as ecosystem processes along gradients of urbanization that run from densely urbanized inner city to more rural exurban environments. We reviewed 300 papers investigating urbanization gradients that were published in peer-reviewed journals between 1990 and May 2007. Sixty-three percent of the papers investigated the distribution of organisms along urbanization gradients. Only five papers addressed the measures used to quantify the urbanization gradient itself. Within the papers addressing the distribution of organisms, 49% investigated the responses of birds to urbanization gradients, and <10% of the papers investigated more cryptic organisms. Most of these studies utilized a variety of broad measures of urbanization, but future advances in the field will require the development of some standardized broad measures to facilitate comparisons between cities. More specific measures of urbanization can be used to gain a mechanistic understanding of species and ecosystem responses to urbanization gradients. While the gradient approach has made a significant contribution to our understanding of the ecology of cities and towns, there is now a need to address our current knowledge gaps so that the field can reach its full potential. We present two examples of research questions that demonstrate how we can enhance our understanding of urbanization gradients, and the ecological knowledge that we can obtain from them.

437 citations