Cities and the Environment (CATE)

Biodiversity is under threat as natural and semi-natural ecosystems continue to decrease in frequency and extent as a function of increased urban development, among other drivers. However, it has become clear that some levels of urban development can continue to support some biodiversity. However, it is not clear how species within different taxonomic groups may respond to similar types and extents of development. Thus, data are needed to assess relationships between urban development and multi-taxa detection patterns. To begin to address this gap, we conducted a concurrent analysis of anuran and avian diversity along an urban-to-peri-urban transect in Greenville, South Carolina, USA. To better align sampling for both taxonomic groups, we conducted passive acoustic sampling along ~10 km of the trail at 400 m intervals. We used unsupervised classification and manual identification to establish levels of detection frequency along the trail of each recorded species. We used geographic information systems (GIS) to establish proportions of land use and land cover including forest, wetlands, and development around each point. We used AIC model selection to identify the most informative land use and land cover variables for each species. There were fewer species detected when there was more development overall but it was varied for specific types of development. Avian and anuran species were detected more frequently in proximity to forests and wetlands, two ecosystem types that are increasingly lost in many urban areas. Moving forward, this data could be useful in the establishment of conservation policies and efforts concerning urbanization, forest fragmentation, and biodiversity in urban greenspaces not formally defined as protected.

Context. Coyotes have confounded lethal-control efforts for over a century, initially as they preyed on livestock the Midwest rangelands in the early 1900s. In the past century, coyotes have expanded their range across the US into rural, suburban, even urban areas in the eastern US where populations are increasing along with calls for management from communities.  Here we examine anthropogenic food subsidy reduction as a possible management tool for coyotes. Compelling explanations for coyote territory-size variation have both a food-availability component and a contender pressure, or competition, component. These factors also influence pack group-size. Ultimately, competition for limited food resources may determine the density of the coyote population. Aims.  To explore this idea, we examined the effects of anthropogenic food resource availability on coyotes in urban, suburban, and rural areas in Rhode Island, USA. Methods. We GPS-collared and tracked 16 coyotes that were, and 15 coyotes that were not, heavily dependent on large, reliable anthropogenic food subsidies.  Anthropogenic subsidies used by coyotes included livestock or deer carcass dumps, farms with small free-range livestock, commercial restaurant garbage, and feral cat colonies.  We compared territory sizes for coyotes living in packs that exploited anthropogenic food subsidies vs. those that did not. Key results. In all cases, the territory sizes of resident coyotes with no detectable anthropogenic food subsidies were 59% larger ( = 11.9 km2) than those of coyotes with territories containing large reliable anthropogenic subsidies ( = 7.5 km2, 95% MCP home range; Wilcoxon test p=0.009).  The total area for high-use regions, or core areas, of unsubsidized coyotes also was 71% larger ( = 3.6 km2) than those with no detectable subsidies ( = 2.1 km2, 95% LSCV contours, p=0.005).  In five cases we were able to remove or add subsidies during the tracking periods of individual coyotes and achieved the same result: territory sizes were smaller when food subsidies were present and larger when subsidies were absent. Conclusions. Heavily food-subsidized coyotes defend smaller territories.  Coyote territories expand to support the group if subsidies are removed, or are absent.  Related research shows adult pack size stays relatively constant though these changes. It follows that the density of coyote packs, or reproductive groups, should increase when large reliable anthropogenic food subsidies are present and decrease when subsidies are removed. Management implications.  Reducing or eliminating anthropogenic food subsidies where they occur in communities with mixed rural-urban landscapes will very likely lower coyote population density. It is a non-lethal strategy for sustainable management of coyotes that leverages their inherent ability to adjust population size based on available food.

Population aging and urbanization increasingly affect the well-being of older people. Urban green spaces (UGSs) can enhance their well-being through cultural ecosystem services (CESs), making CES assessment essential for inclusive cities. However, most studies employing the Maxent model for CES spatial assessment have mainly focused on predicting CES distributions, with limited efforts to translate model outputs into actionable spatial designs for improving CES satisfaction. This study aimed to propose and assess the landscape designs in UGSs informed by the Maxent model, and then to refine the existing National Park Design Code. The findings firstly revealed the spatial distributions of CES satisfaction value indices (SVIs) in both surveyed and unsurveyed UGSs. Furthermore, we proposed targeted landscape designs: (1) increasing bench density and maintaining appropriate spacing, (2) increasing vegetation and locating them centrally, and (3) reducing and strategically placing activity spaces at corners. These designs were validated by Maxent models again. Next, the study suggested refinements to the existing National Park Design Code, including (1) placing high bench densities in activity spaces and controlling the spacing between benches within waterbodies to improve seating availability for older people, and (2) using larger centralized vegetation patches to enhance accessibility. In contrast, (3) placing smaller activity spaces along UGS edges to achieve better separation of noisy and quiet zones. This study established a concrete mechanism for achieving an inclusive urban environment through actionable landscape transformation, offering a set of practical implications to guide urban researchers and practitioners in fostering more age-friendly and inclusive cities.

Coyotes regulate fertility, population recruitment, and territory size, based on food competition, all characteristics that might be leveraged for population management initiatives. In Rhode Island, US, anthropogenic food subsidies provide important resources for coyotes. Prior work has shown that when large reliable subsidies are absent or removed, resident coyotes increase territory size. This is potentially significant to management if the expansion does not cause increases in pack size. We used video camera traps, opportunistic photography, and observation, to make group-size counts. We looked at the influence of levels of anthropogenic food subsidization on pack size. Adult group sizes were smaller in spring/summer (between two and three) and larger in fall/winter (between three and four). Subsidization levels did not influence adult group sizes, which were on average three. One large seasonal subsidy, carcass dumps, did affect adult group counts in winter. The mean number of adults in subsidized sites without carcasses (around three), was significantly lower than for subsidized sites with carcasses (around four). We conclude that removing anthropogenic food subsidies will distribute group members over a larger defended area, decreasing coyote density in that area. By extrapolation, if resource removal is conducted on a larger scale, it could result in fewer territories and a reduction of individuals.

Urban areas are assets to human existence; they also face several challenges. Port Harcourt has abundant green infrastructure and requires environmental conservation practices to protect and manage its environmental resources. The study assessed anthropogenic actions, inactions, outcomes and threats to green infrastructure and environmental conservation in Port Harcourt City. The adopted mixed-methods research approach used a sequential exploratory design. The study employed a judgmental sampling technique to select and interview six (6) key informants from the Rivers State Ministries of Physical Planning and Urban Development, and Environment. Also, an official of Port Harcourt City Local Government Council and a Town Planning professional were interviewed. Satellite imagery and physical observation techniques were also used to assess the green infrastructure and environmental conservation in the study area. Based on the findings, the city has undertaken several activities that have impacted green infrastructure, including preparing master plans, enacting physical planning laws, and establishing physical planning institutions. There are also housing developments, transportation networks, commercial and industrial developments, recreational developments, and land reclamation activities. These activities have led to consequences such as the loss of wetlands, flooding, the disruption of livelihood systems, and increased temperatures. This situation has further threatened the urban environment, including the proliferation of informal settlements, the continuous disappearance of open spaces, diminishing employment opportunities and the emergence of urban heat islands. Therefore, to address the highlighted impacts and promote environmental conservation and sustainable urban development through green infrastructure in the city, there should be deliberate mapping of green infrastructure to protect and conserve it. A framework for sustainable development of green infrastructure for planning, use and management should be prepared. Institutionalise sound urban governance principles into the decision-making process; halt the development of green infrastructure in the city, especially in wetlands, coastal areas, and marginal lands; and encourage the planting of green elements in strategic areas of the city to bring back the Garden City project.  

As the human population increases, habitat transformation due to urban expansion is inevitable, affecting many wildlife species. Birds are frequently used as model species to study the effects of urbanization on wildlife populations due to their environmental sensitivity and ease of observation. While previous studies have investigated changes in species richness and abundance related to urbanization, there is a need for broader-scale, geographically explicit studies associating changes in bird diversity with urban expansion. Using extensive bird census data and high-resolution digitized land use data, this study revealed that species richness, diversity, and evenness within count areas all showed significant positive correlations over the 40-year period, but no significant pattern directly related to urbanization, suggesting the influence of an unidentified independent variable. These results will facilitate the implementation of more effective avian and environmental management strategies in the state of Tennessee.