Urban Ecosystems最新文献

In urban and suburban areas, wildlife and people are often in close quarters, leading to human-wildlife interactions (HWI). Understanding how wildlife interacts with humans and the built environment is critical as urbanization contributes to habitat change and fragmentation globally. The environmental drivers that influence HWIs are largely unknown in some systems, however, especially across multiple spatial scales. Using location and species data from a business that relocates snakes across the Phoenix metropolitan area (Arizona, USA), we found the most frequently removed were venomous (family Viperidae, e.g., rattlesnakes). Nonvenomous snakes were also removed (family Colubridae, e.g., gophersnakes). Using these records, we investigated taxa-specific habitat relationships at two spatial scales. The neighborhood scale focused on front yard measures of cover and vegetation classes, and the landscape scale focused on remote-sensed variables related to vegetation indices and degree of urbanization. Both analyses compared areas where snakes were removed to random locations in the city to evaluate used and available locations of snakes. At the neighborhood scale, snake removals (n = 59) occurred in yards with abundant vegetation and debris cover opportunities compared to random locations. At the landscape scale, snake removal locations (n = 764) had taxa-specific differences, with nonvenomous snakes removed from areas of higher urbanization than venomous snakes, a pattern was likely related to differences in life history and behavior. Environmental variables associated with HWI can vary across different spatial scales. Understanding these environmental characteristics associated with snake removals from residential can focus management activities to reduce potential human-snake conflict.

In an increasingly urbanized world, some raptors successfully colonize and thrive in urban environments, leading to more frequent interactions with humans. These interactions can be either positive, such as providing ecosystem services, or negative, resulting in human-wildlife conflicts. Despite growing literature on these interactions, a comprehensive review focusing on urban environments has been lacking. This study aimed to address this gap by conducting a systematic review using Google Scholar and the Scopus bibliographic database. A total of 45 studies met the search criteria, with a predominant prevalence of the northern hemisphere. Accipitriformes was the most studied order of raptors (50%), followed by Strigiformes (37%), Falconiformes (8%), and Cathartiformes (2%). Positive interactions studied included cultural services, pest control, positive perception, carrion removal, while negative interactions involved safety damage, property damage, negative perception, disease transmission, livestock damage, nuisance and superstitions. Pest control and cultural services were supported by the evidence, although only for specific orders. Carrion removal and aggressiveness appear to decrease with urbanization, although more studies are needed to verify this premise. Both positive and negative perceptions were evident, influenced in part by the knowledge or closeness that people had towards urban raptors. We discuss how the interactions studied influence the daily lives of citizens and, in turn, how human activities shape and influence these interactions. Finally, given that cities are socio-ecological systems, we advocate for methodologies that integrate the social aspects of human-predator interactions along with ecological ones to promote coexistence.

The rapid decline in avifauna populations across North America underscores the urgency of implementing effective conservation strategies. While waterfowl species have generally increased in abundance due to investments in habitat restoration and species management, most other waterbird species have declined. In contrast to the widespread decline of natural habitat for waterbirds, urban greenspaces have proliferated. However, the extent to which urban greenspaces provide habitat for waterbirds is largely unknown. We measured waterbird abundance in Forest Park, Saint Louis, which contains a large expanse of restored waterways. Between 2020 and 2022, we used point counts to quantify alpha and beta diversity of waterbirds across five waterbodies. We also quantified several environmental factors hypothesized to influence waterbird presence including weather, bathymetry, water quality, and prey abundance. We assessed environmental drivers of alpha and gamma diversity using generalized linear mixed models, and beta diversity with Jaccard’s similarity indices and Mantel tests. Water depth and depth heterogeneity were the strongest determinants of alpha diversity. Measured environmental variables did not predict beta diversity but improved model fit when testing gamma diversity. Forest Park is a regionally important urban habitat for waterbirds, hosting 62% (38 species) of the total regional species pool, including nine species of conservation concern and two state endangered species. Urban parks can contribute to waterbird conservation despite habitat loss elsewhere if park managers prioritize habitat restoration. In addition to the total area of waterways, water depth and water depth homogeneity are important considerations to maximize waterbird species diversity in urban greenspaces.

Urban areas form a complex, heterogeneous, fragmented mosaic of habitats, including ecosystems in different degrees of alteration. Nevertheless, some species of birds of prey can thrive in cities. But, there is a knowledge gap regarding the species of birds of prey that who inhabit the cities in Chile, especially those that reproduce in it. Hence, we work in Valdivia, a city that preserves an important natural matrix. The object of this study was to characterize the diversity, abundance, and nest sites of diurnal and nocturnal raptors in the urban area of a city in southern Chile. Twelve species of raptor were recorded, seven diurnal and five nocturnal, 63.1% of the species expected for neighboring rural areas. Twenty-seven nesting sites were recorded two of diurnal raptors and four nocturnal raptors. The availability of nesting sites close to feeding sites, distance to houses, and grassland-shrub cover are essential factors for the success of raptor populations. Cities like Valdivia could offer suitable nesting sites for reproduction, helping to restore habitats for birds of prey.

Urban growth negatively impacts biodiversity through species loss and biotic homogenization. However, cities continue to grow and there are species with certain functional traits that bypass the urban environmental filters persisting in different urban niches. Our objective was to describe taxonomic and functional groups of amphibians and analyze alpha and beta diversity, relating them to environmental variables that characterize fourteen urban green sites with different types and degrees of urbanization, in the metropolitan area of Santa Fe city, Province of Santa Fe, Argentina. We registered 26 species that belong to 13 genera grouped in 5 families: Microhylidae (1), Odontophrynidae (1), Bufonidae (2), Leptodactylidae (10), Hylidae (12). The fourteen surveyed sites were grouped into five categories with similar urbanistic characteristics. Species richness varied from 4 to 15 species per site and between 12 and 19 species per urban green space category. Species corresponded to 10 functional groups and each urban green spaces categories harbor between 7 and 9 functional groups. Beyond the moderate to low beta diversity values, we found that the different urban green spaces categories are complementary as reservoirs of amphibians, since some categories harbor exclusive species or functional groups, while other urban green spaces categories, without exclusive species or functional groups, shelter numerous populations of some species or functional groups.

Increasing in human population causes expansion of urban areas, which threatens forest lands and the biodiversity they harbor. Greenspaces act a critical role maintaining bird diversity within urban areas. Here, we evaluated the effect of spatial characteristics of urban greenspaces on bird species richness to identify the role of greenspace design on bird diversity in Mexico City’s Metropolitan Area. We collected data on bird species richness residing in 44 greenspaces and quantified abiotic, biotic and dispersal attributes of each site. These attributes include size, degree of urbanization within and around the greenspace, vegetation cover, distance between sampled greenspaces, distance to nearby greenspace, distance to the closest natural vegetation patch, distance to city center and distance to periphery of the city. We used Generalized Linear Models to determine the effect of spatial characteristics of urban greenspaces on bird species richness. We then built matrices of beta diversity between greenspaces and assessed bird taxonomic dissimilarity via multivariate Bray-Curtis cluster analysis. Our results showed that bird species richness varies between greenspaces. However, species richness was not correlated with spatial characteristics or biotic attributes (P > 0.05), and we only found marginal correlations between built cover within the greenspace and richness of resident species (P = 0.065) and waterbird species (P = 0.070). Taxonomic similarity between greenspaces was correlated with distance between sampled greenspaces (P < 0.05), however, some dispersal attributes showed no significant effect, such as distance to periphery of the city and distance to the closest natural vegetation patch. Our resultssuggest that distances from areas with greater natural vegetation cover to the innermost parts of the city were too short to function as constraints on the ability of birds to disperse to and colonize urban greenspaces. Our study provides further support for the importance of greenspaces as refuges for conservation of bird diversity in urban areas and shows how urban greenspaces are being used by different bird species within a constantly growing urban landscape.

Human population growth is associated with increased disturbance to wildlife. This effect is particularly acute in urban and periurban areas, where the area of effective disturbance extends beyond that of human presence by the roaming behaviour of pet dogs. Dogs are globally the dominant companion animal, with a population of ~ 12 million in the UK. As urban areas extend, dogs are exercised in green space close to housing. In southeast and southern England these areas include lowland heath, a habitat of high conservation value. To quantify disturbance caused by dog walkers and their dogs, we used GPS units to track the movement of people and their dogs across four lowland heath sites, used a questionnaire to ask about dog walking habits, and mapped potential areas of disturbance caused by dog walkers. Questionnaires were completed by 798 dog walkers and the walks of 162 owners and their 185 dogs were recorded. Mean (± SE) walk time was 56 ± 23 min, walk distance 3.75 ± 1.68 km and dogs were a median distance of 20 m from the owner during walks. Dogs were walked once (44%) or twice (56%) a day. Most (always: 85%; always or occasionally: 95%) dogs were walked off the lead even when signs were present requesting that dogs were kept on a lead. This resulted in up to a 21% increase in reserve area disturbed. In one reserve (Snelsmore Common), > 90% of the area was disturbed by dogs, greatly eroding its conservation value. This work highlights the importance of considering how dog ownership can exacerbate levels of disturbance in sensitive periurban habitats when housing developments are planned.

Abstract

Urban environments are vulnerable to the introduction of non-native species and sometimes contribute to their invasion success. Knowing how urban landscape features affect the population dynamics of exotic species is therefore essential to understand and manage these species. The spotted-wing drosophila, Drosophila suzukii, is a highly polyphagous fruit fly that has become a very problematic invasive species over the last decade. Because of its important damage on fruit production, D. suzukii populations have mainly been studied in agricultural areas, while their dynamics in urban landscape remain poorly explored. The objective of this study was to investigate the role of urban environment in the invasion success of D. suzukii by identifying local and landscape factors driving the abundance of the fly along seasons and urbanization gradients. To achieve this, 526 insect traps were randomly set in four different habitats (urban forest, park, riverside and town centre) along an urbanization gradient in the city of Amiens (France), between September 2018 and August 2019. The influence of landscape and local environmental variables on Drosophilidae species diversity and composition was examined using GLM and multivariate analyses. We found that Drosophilidae species richness and abundance were negatively impacted by urbanization. The Drosophilidae community was dominated by D. subobscura and D. suzukii, but their relative abundance varied with seasons. Drosophila suzukii used urban forest during winter and also during heat waves in summer. The fly was still active in this habitat in winter when the ground was covered with snow. The cover of brambles, shrubs, soil litter and dead wood debris were identified as valuable ecological indicators of the presence of D. suzukii. We highlight the role of the different components of urban environment in the ecology of D. suzukii, particularly with regard to its winter survival. These results could serve for designing management strategies in urban habitats in order to reduce the invasion success of D. suzukii.

Graphical Abstract

Monitoring changes in biodiversity resulting from urban sprawl is an important topic for conservation. Automated biodiversity monitoring methods can quickly collect and process large datasets at minimal cost facilitating effective biodiversity monitoring. Despite being promising, the efficacy of acoustic monitoring in urban areas has not been established. Herein, our aim was to assess the effectiveness of acoustic indices in monitoring urban biodiversity. Thus, we acoustically sampled birds from a large neotropical city (Brasília, Brazil) across a gradient of urbanization. Human identification of recorded species revealed a clear reduction in bird richness in areas of greater urbanization. However, none of the six automated acoustic indices we tested [Normalized Difference Soundscape Index (NDSI), Acoustic entropy (H), Bioacoustic Index (BI), Acoustic Evenness (AEI), Acoustic Diversity Index (ADI), and Acoustic Complexity Index (ACI)], correlate with the degree of urbanization, indicating that these indices may not be a suitable tool for monitoring biodiversity in urban environments. In urban areas, it seems more appropriate to use traditional metrics, that make it possible to accurately identify the heard species. We recommend the need to ground truth the indices and explore alternative acoustic signal’s ability to monitor biodiversity in the complex soundscape of urban environments.