The influence of anthropogenic resources on multi-scale habitat selection by raccoons

With the continuing spread of urban areas, gaining a greater understanding of the effect of human presence on wildlife species is essential for wildlife managers. We determined the influence of anthropogenic resources on home range size and habitat selection of raccoons (Procyon lotor) during summer (June–August) 1996–2000 for 120 raccoons at three sites exposed to varying levels of urbanization and anthropogenic resources, specifically food. Home range estimates were larger (P < 0.05) at the rural site than the suburban and urban sites for both genders. We used compositional analysis to examine raccoon habitat selection at the second-order home range, second-order core area, and third-order home range scales. Woodland was consistently a highly-selected habitat type for both sexes at every spatial scale. Relative to other habitat types, habitat associated with human-related food (human use areas) was selected most often at the urban site, intermediately at the suburban site, and not selected at the rural site. Spatial scale also affected habitat selection. Human use areas were preferentially selected at the second- and third-order level at the urban site, third-order level only at the suburban site, and at neither level at the rural site. Additionally, intersexual differences in habitat selection were reduced at the urban site, with both sexes preferentially selecting for human use areas as well as woodland habitat. Smaller home ranges in urbanized environments are often attributed to the abundant and concentrated anthropogenic resources associated with human activity, but with little empirical support. Our habitat selection analyses followed our predictions that raccoon foraging is strongly influenced by the artificial distribution and abundance of human-related food. Male and female raccoons in urban areas reduce their foraging patterns and focus their foraging activity on anthropogenic foods.     

Home range and habitat use of feral cats in an urban mosaic in Pietermaritzburg,KwaZulu-Natal,South Africa

Feral cats (Felis catus) are one of the world’s worst invasive species with continuing expanding populations, particularly in urban areas. Effects of anthropogenic changing land-use, especially urbanisation, can alter distribution and behaviour of feral cats. Additionally, resource availability can influence home range and habitat use. Therefore, we investigated home range and habitat use of feral cats (n?=?11) in an urban mosaic with varying degrees of urbanisation and green spaces in Pietermaritzburg, KwaZulu-Natal, South Africa. Using global positioning cellular trackers, individual feral cats were followed for a minimum of six months. Minimum convex polygons (MCP) and kernel density estimates (KDE) were used to determine their home range, core area size, and habitat use. Mean home range (± SE) for feral cats was relatively small (95% MCP 6.2?±?4.52 ha) with no significant difference between male and female home ranges, nor core areas. There was individual variation in home ranges despite supplemental feeding in the urban mosaic. Generally supplemental resources were the primary driver of feral cat home ranges where these feeding sites were within the core areas of individuals. However, the ecological consequences of feeding feral cats can increase their survival, and reduce their home ranges and movement as found in other studies.     

Annual and seasonal habitat use of Columbian black-tailed deer in urban Vancouver, Washington

We investigated habitat use of Columbian black-tailed deer in urban Vancouver, Clark County, Washington, at 3 spatial scales: (1) placement of the annual home range within the landscape mosaic, (2) annual and seasonal locations of deer within the annual home range, and (3) short-term use of critical habitats (fawning areas) within seasonal ranges. Annual home range sizes of deer were 162 ha (SD = 133; 95% minimum convex polygon; MCP) and 266 ha (SD = 228; 95% adaptive kernel; AK) for does, and 756 ha (SD = 290; MCP) and 1,235 ha (SD = 382; AK) for bucks. Home range composition of does did not differ from the study area; home ranges of bucks contained more Natural ecological land-use cover types (ELUs) than did the study area. Within home ranges, both does and bucks used Natural ELUs more often than expected by their occurrence in the home range, both annually and seasonally. During the fawning season, does were also found in Natural ELUs more often than expected. Clark County-designated habitat corridors differed from both the study area and deer home ranges in habitat composition, primarily by containing more Natural and other undeveloped ELUs. Deer were located in habitat corridors more than expected. Deer in urban areas appear to use undeveloped habitat types for security. Management that maintains Natural ELUs, such as establishment of wildlife corridors, can provide important habitat components for black-tailed deer in urban habitats.     

A tale of two cities,with bears: understanding attitudes towards urban bears in British Columbia,Canada

The management of black bears (Ursus americanus) in urban and/or exurban settings is of growing concern as these mammals, along with coyotes, cougars and others, begin to re-colonize areas from which they had been extirpated. Urban and exurban landscapes can offer much needed habitat to these space-demanding creatures, thereby buffering habitat losses in other areas and protecting populations of these species, but only if conflicts between these animals and humans can be managed and minimized. In the case of urban black bears, they can become quickly labled as a “problem” bear if they become too reliant on human garbage or other food sources such as fruit trees. A “problem” bear usually becomes a dead bear. In collaboration with the Northern Bear Awareness Society in Prince George, British Columbia, Canada, UNBC researchers undertook two surveys of Prince George over a 3 year period and a companion survey in the city of Coquitlam, BC to examine attitudes towards urban bears. The research found that residents of both cities, in spite of regular and close encounters with black bears, strongly supported the presence and preservation of bears within an urban setting, largely due to conservation concerns. Both communities were supportive of non-lethal control of “problem bears” and supported the use of warnings and fines to discourage human behaviors that created human-bear conflicts over lethal controls. These findings offer support for municipal governments to reconsider approaches to urban bear management.

     

Raccoon use of the urban matrix in the Baltimore Metropolitan Area, Maryland

The raccoon is often considered a synanthropic species; however, most urban research on this species has been restricted to urban parks or green spaces. Little is known about the persistence of synanthropic characteristics in the raccoon within the urban matrix. We examined density, den selection, home range size, habitat selection, and survival for adult raccoons (Procyon lotor) during summer (June?CAugust) and autumn (September?CNovember) in two residential neighborhoods, Linthicum located inland, and Riviera Beach on a peninsula in the Potomac river, in Southern Maryland. Den site selection varied by gender (P?=?0.0002) and study site (P?=?0.052), and study site interacted with gender (P?=?0.0063), with female raccoons denning preferentially on the ground and male raccoons in human structures in Riviera Beach while in Linthicum females denned preferentially in trees and males avoided human structures. Seasonal home range size was larger for males (P?<?0.0001) than females at both sites. Habitat selection varied at different hierarchical levels, and between gender, season and site. Intersite differences in habitat selection were apparent at the second order and third order scale. Aquatic and urban habitat was ranked high and woodland consistently lowest in second order scale at Riviera Beach while urban habitat was consistently ranked lowest at Linthicum where woodland ranked highest. Between the hierarchal scales (2nd and 3rd order) a difference in habitat selection occurred at Linthicum only where urban habitats ranked lowest at 3rd order. The differences in patterns of habitat selection we observed between two urban sites at different hierarchical scales suggest that resource selection is dependent upon the specific characteristics of the site and that raccoons exhibit variable responses to changes in landscape features. Finally, male survival tended to be lower (P?=?0.079) than female survival in both study sites. Our results reveal that raccoons can continue to exhibit synanthropic characteristics within the urban matrix even in areas with little natural habitat. This ability to adjust to different levels of development allows the raccoon to occur throughout most parts of the urban landscape, which has important management implications for human-raccoon conflicts and disease management.     

Urban bird conservation: presenting stakeholder-specific arguments for the development of bird-friendly cities

Following the call from the United Nations Convention on Biological Diversity “Cities & Biodiversity Outlook” project to better preserve urban biodiversity, this paper presents stakeholder-specific statements for bird conservation in city environments. Based upon the current urban bird literature we focus upon habitat fragmentation, limited habitat availability, lack of the native vegetation and vegetation structure as the most important challenges facing bird conservation in cities. We follow with an overview of the stakeholders in cities, and identify six main groups having the greatest potential to improve bird survival in cities: i) urban planners, urban designers and (landscape) architects, ii) urban developers and engineers, iii) homeowners and tenants, iv) companies and industries, v) landscaping and gardening firms, vi) education professionals. Given that motivation to act positively for urban birds is linked to stakeholder-specific advice, we present ten statements for bird-friendly cities that are guided by an action perspective and argument for each stakeholder group. We conclude with a discussion on how the use of stakeholder-specific arguments can enhance and rapidly advance urban bird conservation action.     

Spatial distribution and the value of green spaces for urban red-tailed hawks

Raptors increasingly live and nest successfully in urban areas. In the urban landscape of Hartford, CT, red-tailed hawks established home ranges in large green spaces such as parks, golf courses, and cemeteries but also nested successfully in the commercial district of downtown and in densely built urban and suburban neighborhoods. Data collected from 11 radio-tagged breeding adult hawks indicated that year-round home ranges averaged 107.7 ha, much smaller than home ranges reported for hawks inhabiting rural areas. Most hawk home ranges had multiple core areas that were usually associated with favored perches or larger patches of ‘usable’ green space, defined as patches ≥0.25 ha in size, and home range size was positively associated with larger usable green space patches in core areas. Most nests were located in the largest core area and were within a larger patch of green space within the largest core area. Rather than just the amount or size of green space patches, the value of urban green spaces for these hawks likely also varies with the number and proximity of suitable perches such as buildings or tall trees, types and density of prey, and amount of human activity in and adjacent to these spaces. Territoriality and intraspecific competition may also influence home range size and dispersion of red-tailed hawks nesting in Hartford. In this urban area, mortality due to ingestion of rodenticides and collisions with vehicles affected hawk reproductive success.

     

Homeownership and Volunteering: An Alternative Approach to Studying Social Inequality and Civic Engagement1

Previous research on volunteering finds significant differences by race and social class. We augment these findings by examining a largely ignored measure of social class: tenure status, the distinction between renters and homeowners. We test a theory that predicts people volunteer more if they have a “stake” in their community and we use the value of their home as a measure of the size of this stake, with renters having no stake at all, using data from the 2003 Panel Study of Income Dynamics. We find that although homeowners volunteer more than renters, the value of their home has no influence on their volunteer work. Length of residence in the neighborhood has a positive effect on volunteerism. Tenure status partially mediates the influence of race and family income on volunteering but not education.     

Snake communities on the urban fringe in the Sonoran Desert: influences on species richness and abundance

Sonoran Desert habitat in southern Arizona is increasingly altered by urban development near metropolitan areas. Understanding how reptiles respond in these impacted habitats is critical to conservation efforts to retain intact biotic communities, especially those with a high diversity of reptile species. We surveyed snakes at one impacted site on the northern edge of the Phoenix metropolitan area in desert/urban interface, and at another site in a desert/rural interface near Florence, Arizona. The site near Phoenix was lower in species richness (15 spp.), and evenness: two snake species accounted for 75 % of all snakes encountered (total = 420). The site near Florence was higher in species richness (19 spp.), and a more even community: no species accounted for more than 20 % of snakes encountered (total = 594). Sampling methodology had a strong influence on species richness and abundance of snakes at the respective sites: road riding, coverboards, and traps each provided evidence of unique species missed by other methods. These results were compared with inventories at three other sites in the central Sonoran Desert of Arizona, and are consistent with the view that the impacted site near Phoenix is uneven, potentially as a result of a single species reacting to shifts in prey availability.     

Seasonal activity patterns of sympatric eastern gray squirrels (Sciurus carolinensis) and fox squirrels (Sciurus niger) in a Midwestern metropolitan region

Niche partitioning reduces interspecific competition, facilitating coexistence. In urban ecosystems, however, habitat loss reduces species’ ability to spatially partition activity. Temporal partitioning may thus increase in urban areas as species, unable to avoid each other spatially, partition time to avoid competition. In Midwestern US cities, eastern gray squirrels (Sciurus carolinensis) and fox squirrels (S. niger) co-occur and compete for resources. We identified urban gray and fox squirrel activity patterns and how they vary with season, land cover, and among sites where they do and do not co-occur using camera-trap data. Both species’ activity patterns varied with season and canopy and impervious surface cover. Gray squirrel activity patterns varied in the presence of fox squirrels only in the fall, providing limited support for our temporal partitioning hypothesis. Temporal niche partitioning may thus play a role in supporting these species co-existence when competition is seasonally-elevated (e.g., fall hording), but appears less important in other seasons.

     

BIMBY’s first steps: a pilot study on the contribution of residential front-yards in Phoenix and Maastricht to biodiversity,ecosystem services and urban sustainability

Large parts of urban space around the world exist of small-scale plots such as domestic gardens. These small-scale urban spaces carry potential for enhancing biodiversity, sustainability and ecosystem services in and beyond cities. However, domestic gardening and residential garden designs are often guided by aesthetics and ease more than by the aim to create habitat and biological diversity. Yard-management decisions impact socio-ecological systems in various ways, for example through irrigation patterns, fertilization or the use of pesticides or through the choice for exotic species that may become invasive over time. Yard-management decisions can also positively influence the presence of pollinators, improve soil quality or even foster small scale ‘Wildlife Habitats’ that can function as ecological stepping stones to the wider environment. In this paper a pilot assessment is presented of the contribution of residential front-yards in Phoenix (Arizona) and Maastricht (The Netherlands) to biodiversity, ecosystem services and sustainability by applying the BIMBY (Biodiversity in My (Back) Yard) framework.     

Persistence and survival of the spider <Emphasis Type="Italic">Nephila plumipes</Emphasis> in cities: do increased prey resources drive the success of an urban exploiter?

Species that successfully inhabit urban ecosystems are rare, and urbanisation often drives localised extinctions of native species. Nonetheless, some species take advantage of the novel conditions available in cities and increase in abundance. Trends in the abundance and distribution of species in urban areas have received much attention, but the precise elements of urban ecosystems that affect the survival of urban-dwelling species are largely unknown. Animals that successfully exploit urban environments may do so because of increases in the availability of resources or habitats. Here we assess the effects of anthropogenic landscapes and prey abundance on the persistence of an orb-weaving spider, Nephila plumipes. We assessed spider persistence for six months in situ along an urban gradient in Sydney. We then transplanted spiders from a common garden into sites along the gradient, monitored their persistence in the new environment and measured a suite of environmental variables at local and landscape scales. The abundance of prey was closely linked with spider persistence, in both the survey and the transplant experiment, and was positively associated with anthropogenic habitats. The surveyed spiders survived longer when located closer to the coast and transplanted spiders persisted longer in smaller sites with more impervious surfaces and reduced vegetation cover. Our study shows that urbanisation has a strong effect on potential prey abundance and can lead to increased persistence of N. plumipes, demonstrating the broad impacts that habitat disturbance can have on the life history and trophic interactions of city-dwelling animals.     

Urban landscape matrix affects avian diversity in remnant vegetation fragments: Evidence from the Phoenix metropolitan region, USA

Biodiversity conservation in urban areas has become increasingly important as cities have expanded to cover larger proportions of landscapes across the world. The careful planning of habitat reserves within urbanized areas has the potential to make significant contributions to regional biodiversity. We surveyed the passerine community in 15 habitat reserves within the Phoenix metropolitan region and explored the relationships between community composition and urban land uses surrounding the reserves. Diversity of different guilds was affected in substantially different ways by reserve characteristics and surrounding urban land use. Guilds responded to land use at all three scales included in the study ?C 200 m, 1000 m and 2500 m. The responses of four guilds, synanthropic, non-synanthropic, insectivore and feeding generalist, were well predicted by the factors considered here. Reserve characteristics (area, shape, isolation), particularly area, had effects on all four of these guilds with non-synanthropic and insectivore species responding positively to area, while synanthropic and feeding generalist species responded negatively. Land use type surrounding the reserves had significant effects on all of these guilds, except for feeding generalists. High density, high diurnal activity land uses decreased diversity, while medium density, low diurnal activity uses increased the diversity of some guilds, particularly insectivores, probably by providing supplemental habitat. This study provides new evidence from an arid urban landscape that not only reserve characteristics, but also surrounding urban land use should be considered during conservation planning, especially if non-synanthropic or insectivore species are among the targeted species.     

The structure of a micro-bat community in relation to gradients of environmental variation in a tropical urban area

We investigated patterns of community structure (species composition, foraging activity, and nightly foraging patterns) of bats in relation to gradients of environmental variation in a tropical urban area. A total of 32 sites spread equally across eight habitat types were sampled in the city of Townsville, North Queensland, Australia. Each site was sampled on 3 non-consecutive occasions using automated AnaBat systems. Eleven species were confidently identified while a possible four more were identified only to the genus level. Ordination of environmental variables measured at these sites identified two distinct environmental gradients reflecting the degree of urbanisation and foliage density. With increasing urbanisation there was a decline in species richness and total foraging activity. We used regression trees to characterise foraging preferences of each species. This analysis suggested that only one species of Mormopterus was able to exploit the resources provided by urbanisation. This species foraged in areas with higher numbers of white streetlights. The remaining species of bats preferred to forage within close proximity to natural vegetation and with low numbers of streetlights. The density of vegetation in long-established suburbs did not substantially reverse the trend for urban areas to have fewer bat species than original habitats.     

Aspects of the ecology and behaviour of a potential urban exploiter,the southern tree agama,Acanthocercus atricollis

Urbanisation has caused significant alterations to ecosystems, generally resulting in decreased biodiversity. However, certain animal species persist and thrive in urban environments by making use of available opportunities, anthropogenic resources, infrastructure and increased ambient and surface temperatures. These species are known as urban exploiters. We investigated the southern tree agama, Acanthocercus atricollis population trends, habitat use and basking and shading behaviour in a high-density urban human-populated housing metropolitan area in Pietermaritzburg, KwaZulu-Natal, South Africa. We marked individual southern tree agamas to determine habitat use and territories (n?=?37). The southern tree agama population density was high, and they had established set territories here. We conducted monthly observations (February 2017–July 2017 and March 2018–February 2019) to determine the degree of basking and shading behaviour with season and time of day and location. Southern tree agamas invested more than half of their time (57%) in basking behaviour during the overall observational study period. Basking and shading patterns changed with season and time of day. The number of basking southern tree agamas decreased during winter and basking commenced later. We found that increased anthropogenic infrastructure and supplementary food availability, decreased predators, and basking opportunities could have had an influence on their population increase and that the southern tree agama is a potential urban exploiter.

     

Impact of urban structure on avian diversity along the Truckee River, USA

Urban riparian habitats are potentially important resources for native birds in arid ecosystems. Most studies have assessed the value of urban riparian habitat in terms of vegetation and natural resources; however, the surrounding land use and infrastructure may determine the viability of urban habitat. We studied the impact of urban structure, the combination of land use, infrastructure and vegetation variables that work together to shape the urban environment, on avian riparian habitat in the Truckee Meadows, Nevada, USA. Land use and infrastructure explained avian species richness and abundance better than local vegetation alone, but community resemblance was more strongly correlated to vegetation. Avian species guilds responded differentially to surrounding land use, suggesting there may be a functional difference between land use types. The best models for bird diversity used urban structure (both land use and vegetation) to describe potential habitat. Urban structure describes urban habitat in ways that vegetation variables alone cannot. Studies that ignore land use and infrastructure and other socioeconomic variables are likely missing key functional differences within urban ecosystems, and may miss the potential for compatible development that encourages both biodiversity and urban growth.     

Urban and wildland herpetofauna communities and riparian microhabitats along the Salt River, Arizona

Metropolitan areas are continually expanding, resulting in increasing impacts on ecosystems. Worldwide, riverine floodplains are among the most endangered landscapes and are often the focus of restoration activities. Amphibians and reptiles have valuable ecological roles in ecosystems, and promoting their abundance and diversity when rehabilitating riparian systems can contribute to reestablishing degraded ecosystem functions. We evaluated the herpetofauna community by measuring abundance, richness, diversity, and species-habitat relations along three reaches (wildland, urban rehabilitated, and urban disturbed reaches) varying in degree of urbanization and rehabilitation along the Salt River in central Arizona. We performed visual surveys for herpetofauna and quantified riparian microhabitat along eight transects per reach. The wildland reach had the greatest herpetofauna species richness and diversity, and had similar abundance compared to the urban rehabilitated reach. The urban disturbed reach had the lowest herpetofauna abundance and species richness, and had a similar diversity compared to the urban rehabilitated reach. Principal Component Analysis reduced 21 microhabitat variables to five factors which described habitat differences among reaches. Vegetation structural complexity, vegetation species richness, densities of Prosopis (mesquite), Salix (willow), Populus (cottonwood), and animal burrow density had a positive correlation with at least one herpetofauna community parameter, and had a positive correlation with abundance of at least one lizard species. Rehabilitation activities positively influenced herpetofauna abundance and species richness; whereas, urbanization negatively influenced herpetofauna diversity. Based on herpetofauna-microhabitat associations, we recommend urban natural resource managers increase vegetation structural complexity and woody debris to improve herpetofauna habitat when rehabilitating degraded riparian systems.     

Exiting or retaining owner-occupied housing in the United States 1999–2009: How do social programs matter?

This research examines exits from homeownership in the United States between 1999 and 2009 using data from the Panel Study of Income Dynamics. We first document the extent to which homeowners exited owned housing (to a rental unit or a rent-free unit) during that time period. Second, we examine how socio-demographic characteristics, housing characteristics, debt levels, and receipt of public and private transfers are associated with exiting (or retaining) homeownership, with a particular focus on whether transfers counteract earnings decreases and/or housing cost increases to assist homeowners in retaining their homes. We also investigate whether these associations differ for several subgroups of homeowners defined by their location in the income distribution and race. Findings from regression models that include individual, year, and state fixed effects highlight the role of both labor markets and housing markets in influencing exits from homeownership. More generous and universal public transfers (such as OASDI) appear to help owners retain homes, whereas less generous and means-tested transfers do not. At the same time, the influences of universal transfers on retaining a home are small in magnitude compared to those of decreases in earnings and home values as well as increases in payment-to-income and consumer debt-to-income ratios.