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1.
Increasing urbanization across the southeastern United States presents unique challenges for wildlife; however certain species have learned to adapt and thrive in these environments. Coyotes (Canis latrans), bobcats (Lynx rufus), red foxes (Vulpes vulpes) and gray foxes (Urocyon cinereoargenteus) are four common medium-sized carnivores that have become closely associated with urban areas. The goal for this study was to determine how urban landscape features influence density and occurrence of these species in a small urban area and to evaluate if any effects were similar to those observed in larger urban areas. We conducted two eight-week camera surveys in the city of Nacogdoches, Texas (pop. 32,699) and immediate surrounding areas in summer and fall 2013. We evaluated single-season spatially explicit capture-recapture and occupancy models to estimate density, and occurrence, respectively, based on anthropogenic and natural features around each camera site. Coyotes (fall: 1.38 coyotes/km2) and bobcats (fall: 0.64 coyotes/km2) were associated with areas of green space, but their response to large and small green spaces changed seasonally. Conversely, red foxes (fall: 2.53 red foxes/km2) were more likely to occur near developed areas and were less detectable in areas with greater probability of coyote presence in fall only. In summer, gray foxes (fall: 0.05 gray foxes/km2) were more likely to occur in areas with lower building density and closer to buildings. This study indicates coyotes, foxes and bobcats respond to small-scale urbanization in a similar manner as large-scale urbanization.  相似文献   

2.
Gibeau  Michael L. 《Urban Ecosystems》1998,2(2-3):129-139
Little information is available on the degree to which coyotes (Canis latrans) use urban habitats. In the past, interactions between coyotes and humans have precipitated several instances of coyote aggression towards humans. Consequently, I analyzed use of urban habitats by coyotes and the possibilities for aggressive encounters with humans. In this study, 11 radio-collared coyotes were monitored between July 1991 and September 1992. Use/availability analysis demonstrated a clear difference in use of natural habitats between summer and winter. Urban habitats were used in direct proportion to availability during all time periods, except during the day in summer when coyotes avoided intense human activity. Campgrounds were not an attraction during either season. For the most part, coyotes in the vicinity of Banff used habitats available to them regardless of human activity. Evidence does not suggest the coyote population in the vicinity of Banff is predisposed to aggression due to familiarity with humans. The relationship between the data and coyote aggression towards humans is discussed.  相似文献   

3.
Urban plant biodiversity is influenced by both the physical environment and attitudes and preferences of urban residents for specific plant types. Urban residents are assumed to be disconnected from their immediate environment, and cultural and societal factors have been emphasized over environmental factors in studies of landscaping choices. However, we postulate that local climatic and environmental factors can also affect preferences for plant attributes. Therefore, spatial and temporal patterns in urban tree biodiversity may be driven not only by the direct effect of environmental variables on plant function, but also by the effect of environmental variables on attitudes toward trees and associated choices about which types of trees to plant. Here, we tested the relative effects of socio-economic and local environmental factors on preferences toward tree attributes in five counties in southern California in and surrounding Los Angeles, based on 1,029 household surveys. We found that local environmental factors have as strong an effect on preferences for tree attributes as socio-economic factors. Specifically, people located in hotter climates (average maximum temperature 25.1 °C) were more likely to value shade trees than those located in cooler regions (23.1 °C). Additionally, people located in desert areas were less likely to consider trees to be important in their city compared with people located in naturally forested areas. Overall, our research demonstrates the inherent connections between local environmental factors and perceptions of nature, even in large modern cities. Accounting for these factors can contribute to the growing interest in understanding patterns of urban biodiversity.  相似文献   

4.
There has been an increasing interest in the evolution of urban forests. This research uses historic and digital aerial photography to quantify changes in tree density in Los Angeles, California since the 1920’s. High-resolution geographic information system analysis (4 to 6 time periods) of three regions (San Fernando Valley, Hollywood, Los Angeles Basin) of Los Angeles reveals that there has not always been an increase in tree density with time. Tree densities on public and private land were highest in the 1940’s in Hollywood, while the San Fernando Valley and Los Angeles Basin experienced a near linear increase in tree density on both private and public land since the 1920’s. When historic tree density reconstructions were examined for the 15 Los Angeles city council districts from the 1920’s, 1950’s and 2006, most districts in Los Angeles have experienced a significant increase in tree density, however, there has been wide variation in tree densities among city council districts. Trees densities have generally been higher on private land since the 1920’s and currently tree densities on private land are significantly higher than on public land. Results suggest the evolution of urban forests in Los Angeles mirrors the dynamics of urban forests in desert and grassland cities. It is possible to reconstruct the development of urban forests in sections of cities using historic and contemporary aerial photography. We estimated that Los Angeles averages approximately 104 trees per hectare (82 private land, 22 public land) based on 2006 imagery at 0.3 m resolution, however, field validation suggests that we identified only 73% of trees. Although there is still space to plant trees on public land, private land owners will need to be heavily involved in order to achieve the goals of Los Angeles’ Million Tree Initiative.  相似文献   

5.

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.

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6.
A diversity of indigenous and alien wildlife persists in suburbia, and provides residents with the opportunity to experience wildlife. Suburban gardens may serve as refugia and foraging grounds for many primate species allowing them to populate within a largely urbanized landscape. However, this has led to the increasing human interactions with them, resulting in conflict. Our study investigated the perceptions of suburban residents towards urban vervet monkeys Cercopithecus aethiops pygerythrus within the Msunduzi and Ethekwini municipalities, KwaZulu-Natal, South Africa. We assessed how these related to the monkeys’ presence, activities and interactions in residential gardens, and the value of wildlife to residents. Assessment was conducted through an online questionnaire survey. General attitudes of residents to vervet monkeys were canvassed by assessing the respondents’ level of active engagement in wildlife watching within their properties. We analyzed 603 surveys submitted online using logistic regression and ordinal regression models. We ascertained that vervet monkeys were disliked by 29% of residents due to their aggressiveness, destructive behaviour in gardens and households, and perceived threat to native wildlife. Frequency and duration of foraging vervet monkeys in residents’ gardens was influenced by the presence of pet dogs, fruiting trees, tall trees (>2 m), ratio of indigenous to alien vegetation of gardens, residency type, and active and passive food provisioning. Despite conflict, the majority of respondents appreciated urban wildlife (67%) and actively engaged in wildlife watching (88%), emphasizing the importance of incorporating human dimension values into the management of urban biodiversity. Our study highlights the value of citizen science in providing mechanisms for identifying priority management and conservation efforts at the highly complex human-wildlife interface in an urbanized landscape.  相似文献   

7.
We examined how predator or prey presence, as well as local and landscape factors, influence the distribution of coyotes (Canis latrans) and white-tailed deer (Odocoileus virginianus) in the Chicago metropolitan area. We collected data for 2 years at 93 study sites along 3 transects of urbanization using motion-triggered cameras. Our primary objective was to determine the relationship among coyote and deer spatial and temporal distribution, habitat characteristics, and human activity using multi-season patch occupancy models. Coyote occupancy was most strongly linked to rates of site visitation by humans and dogs, and was more likely farther from the urban center, with coyote colonization of sites inversely related to road density, housing density, and human and dog site visitation. Deer more frequently occupied sites with high canopy cover near water sources and colonized smaller sites with reduced housing density and human and dog presence. Expected predator–prey dynamics were altered in this highly urban system. Though we predicted deer would avoid coyotes on the landscape based on an “ecology of fear” framework, deer and coyote occupancy showed a strong positive association. We suggest that a scarcity of quality habitat in urban areas may cause the species to co-occupy habitat despite potential fawn predation. Modifying human foot traffic in green spaces may represent a useful tool for management and conservation of large urban mammals.  相似文献   

8.
Coyotes (Canis latrans) have inhabited Florida (USA) since the 1960s and are currently found throughout the state. Our objective was to obtain information on enteric parasites of coyotes from two different habitats. Fresh coyote fecal samples were collected from protected and suburban habitats in Pinellas County, Florida, USA (27o54′ N, 82o41′W) from May 2005 to March 2007. A standard fecal flotation examination and formalin-ethyl acetate sedimentation protocol were utilized on fecal samples from both habitats. Five newly documented coyote parasites were documented: one cestode (Hymenolepis spp.), one nematode (Ascaris spp.), and three protozoa (Balantidium coli, Blastocystis spp., and Entamoeba histolytica). Nine hitherto unreported parasites for FL coyotes were also discovered: two cestodes (Diphyllobothrium latum and Dipylidium caninum), two nematodes (Toxocara canis and Uncinaria stenocephala), one trematode (Paragonimus spp.), and four protozoa (Cryptosporidium spp., Giardia canis, Cystoisospora spp., and Sarcocystis cruzi). The protected area supported significantly more undocumented (i.e., newly identified) parasites for FL coyotes, and Protozoa as compared to the suburban area. Florida coyotes are likely more susceptible to infection by novel parasites because of their rapid range expansion and lack of acquired immunity. In addition, rapid habitat loss and urbanization in Florida may increase the probability of disease transmission between wild and domestic canids. We suggest preventative measures that may lower the risk of parasitic infection and promote co-existence with coyotes in urban landscapes.  相似文献   

9.
Many observers have noted that immigrants to the United States are highly concentrated in the largest metropolitan areas of a relatively few states. Though immigrants diffused into many places that had previously seen relatively few immigrants during the 1990s, as of the 2000 census, 77 percent of the nation's 31.1 million foreign born residents still lived in six states — California, New York, Texas, Florida, New Jersey, and Illinois. According to the 2000 census, the two largest metropolitan areas, Los Angeles and New York, accounted for one third of all immigrants ( http://www.census.gov/Press‐Release/www/2002/demoprofiles.html ). While immigrants moved into many new areas during the 1990s, making the challenge of incorporating their children a national issue, their concentration in our largest cities remained pronounced.  相似文献   

10.

Little is known about the relatedness structure of carnivores living in urban areas, where green spaces may vary in size and resource availability. We examined the minimum population size, relatedness structure, and genetic diversity of a recently established population of eastern coyotes (Canis latrans) inhabiting New York City (NYC). The population has been established for approximately 25 years, and sample collection for genetic analysis has been ongoing since 2010. We genotyped 234 scat, eight tissue, and three blood samples at nine microsatellite loci. We identified 45 individual coyotes with a male-biased sex ratio of 2.2:1. We also found moderate to high levels of genetic diversity, with average observed heterozygosity of 0.779 and mean number of alleles per locus of 7.8. Most of the green spaces surveyed supported a single group of closely related coyotes in each. Relatedness comparisons between parks also indicated that coyotes compared across different parks were also closely related. We identified two unrelated mated pairs and found no support for polygamy. The high incidence of relatedness suggests that the coyote population is descended from a small number of founding individuals. Additionally, we genetically recaptured several coyotes, including one individual sampled in the Bronx and in Queens, with a median of 103 days between resampling. This result indicates that the coyotes are persisting in some of the isolated greenspaces of New York City and able to move successfully between them.

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11.
We collected ants from six urban and one forest land-use types in Raleigh, NC to examine the effects of urbanization on species richness and assemblage composition. Since urban areas are warmer (i.e., heat island effect) we also tested if cities were inhabited by species from warmer/drier environments. Species richness was lower in industrial areas relative to other urban and natural environments. There are two distinct ant assemblages; 1) areas with thick canopy cover, and 2) more disturbed open urban areas. Native ant assemblages in open environments have more southwestern (i.e., warmer/drier) distributions than forest assemblages. High native species richness suggests that urban environments may allow species to persist that are disappearing from natural habitat fragments. The subset of species adapted to warmer/drier environments indicates that urban areas may facilitate the movement of some species. This suggests that urban adapted ants may be particularly successful at tracking future climate change.  相似文献   

12.
In recent years, the appearance of egg donor advertisements in American college newspapers, sometimes offering five‐ and six‐figure fees to ‘genetically gifted’ donors, has given rise to critical comment on both sides of the Atlantic, and has caused some to fear that the use of these procedures will eventually result in the creation of ‘designer babies’ with preselected genetic qualities. Whether such fears will be realized depends, to a great extent, upon how both the participants themselves and society as a whole come to view and understand these procedures. This article explores emerging images of assisted reproduction through an analysis of the use of metaphor in egg donor ads that appeared in the student newspaper of the University of California, Los Angeles. I argue that the attitudes displayed in these ads result from a mapping of existing cultural stereotypes associated with biological parenthood, including the role of childbearing in marriage and ‘coupledom’, onto the assisted‐reproduction process, and that these metaphors are used precisely because they construct this cultural model and adapt it to the new reality of the assisted‐conception experience.  相似文献   

13.
Urban lakes are often monitored and managed with limited consideration of adjacent communities. Generally, when communities are considered in relation to urban lakes, they are viewed simply as sources of pollutants. Given the inevitable interactions between an urban lake and the surrounding inhabitants, the community must be considered explicitly when assessing the ecosystem health of urban lakes, as the two entities intrinsically comprise interrelated parts of a single ecosystem. In this study, the reciprocal links between a residential community and a series of urban lakes in South East Queensland have been examined to facilitate a dynamically linked, fully integrated ecosystem health assessment of constructed urban lakes. Residents’ attitudes towards, and values derived from, a series of urban lakes were surveyed, as well as residents’ behaviours which may impact upon urban lake health. The results indicate that residents derive both tangible and intangible benefits from the urban lakes, but feel little responsibility for lake health or custodianship over the lakes. Greater recognition within urban lake management frameworks of the links between urban lake systems and their surrounding communities may help to foster and enhance both community well-being, a greater sense of custodianship for such systems and improved management.  相似文献   

14.
The main objective of this article is to acknowledge and examine the material culture of the homeless in the urban context of downtown areas in Sao Paulo, Los Angeles and Tokyo. Firstly, I introduce some aspects of the complex process of vital package production, which concerns the social function of design and the role of products in our late industrial society. In exploring this process of homeless material culture, I then describe the reverse sense of some of the products and materials re‐functionalized by the homeless. Then, in a brief analysis of design, wasteful culture, products, life cycle and obsolescence, I claim that homelessness and design are linked to the public spaces of metropolitan areas and global cities, as a consequence of the social‐spatial exclusionary processes due to spatio‐economic conflicts that constitute contemporary urban restructuring.  相似文献   

15.
Humans can profoundly shape animal community dynamics, but such effects have rarely been evaluated for terrestrial carnivores. Humans affect carnivores in both spatial and temporal dimensions via the chance of human encounter and alteration of the landscape through urban development. We investigated three hypotheses regarding how humans mediate the sympatry of larger, dominant carnivores with their smaller, subordinate counterparts. We tested these hypotheses by examining the spatio-temporal dynamics of a dominant carnivore (coyote Canis latrans) and its subordinate competitor (red fox Vulpes vulpes) across an extensive urban park system. We found that dominant and subordinate carnivores exhibited strong and often opposing spatio-temporal responses to the probability of human encounter and urban development. Spatially, coyotes visited more highly developed sites less frequently while red foxes exhibited an opposing response. Temporally, both species avoided humans via nocturnal activity. Spatio-temporally, red foxes avoided coyotes at all sites and avoided humans at highly developed sites, whereas coyotes showed a positive association with humans at such sites. Our analysis indicates that areas with higher urban development might act as spatial refugia for some subordinate carnivores against interference from larger, dominant carnivores (a “human shield” effect). Our findings also reveal that broad-scale spatial avoidance is likely a crucial component of coexistence between larger, dominant carnivores and humans, whereas finer-scale spatio-temporal avoidance is likely a key feature of coexistence between humans and smaller, subordinate carnivores. Overall, our study underscores the complex and pervasive nature of human influence over the sympatry of competing carnivores inhabiting urban systems.  相似文献   

16.
Keogan  Kevin 《Sociological Forum》2002,17(2):223-253
American immigration has long been characterized by spatial concentration within major urban areas. Los Angeles and New York City are two of the most important immigrant meccas today. Recent studies of immigrant adaptation within these cities have emphasized material factors at the expense of cultural considerations. This paper adopts a comparative perspective to demonstrate extreme differences in the symbolic construction of identity vis-a-vis immigrants in these two urban areas. Using The Los Angeles Times and The New York Times as indicators of elite cultural orientations, a content analysis is performed. The results demonstrate the social construction of an exclusive threat narrative in Southern California, and an inclusive immigrant as victim narrative in the New York metropolitan area. I argue that this extreme variation in cultural orientations must be understood as the result of divergent material and symbolic contexts. In order to demonstrate the importance of cultural factors, this paper focuses on symbolic differences between these areas and the influence these differences have on the political process of inclusion/exclusion.  相似文献   

17.
Urbanized areas show a high proportion of non-native plants and can work as dispersal points to the surrounding areas. Ensenada is a fast growing city located in the northwestern peninsula of Baja California (Mexico). It is the southern extreme of a bi-national, coastal urban corridor that extends from Los Angeles, California south to Ensenada. This corridor is part of the biodiversity hotspot of the California Floristic Province. The aim of this study was to analyze the composition and distribution of the spontaneous flora in the city of Ensenada. We systematically sampled two differentiated urban environments, vacant lots and arroyos, in 2006 and 2007. We found a total of 158 plant species, 61% of them were non-native species. Arroyo areas showed higher non-native species richness than vacant lots (21.9 vs. 13.6 species/transect) and could be potential dispersal vectors for non-native species to natural areas outside of the city, or in the reverse direction also.  相似文献   

18.

Urban environments present wildlife with major challenges and yet surprising numbers of species have colonised towns and cities globally. Despite the growing realisation that urban centres can be important habitats for wildlife, why some species do better than others in urban environments remains poorly understood. Here, we compare the breeding performance of an apex predator, the peregrine falcon (Falco peregrinus), in urban and rural environments, and test whether variation in reproductive success between and within environments is driven by prey. Historical breeding data were collected from raptor study groups across Great Britain between 2006 and 2016, from 22 urban and 58 rural nest sites, involving 101 and 326 nesting attempts, respectively. Prey density, biomass and diversity around the individual nests was estimated using modelled estimates from a national bird census. Urban peregrines produced more fledglings and had a higher overall nesting success (i.e. whether a nesting attempt was successful or unsuccessful) than rural peregrines. Prey density and biomass were significantly higher, and diversity significantly lower, in the urban sites, and explained the variation in reproductive success within both the urban and rural environments. Therefore, urban environments in Great Britain appear to provide peregrine falcons with superior habitats in terms of prey availability compared to rural habitats. We conclude that some apex predators can benefit from urban environments and that urban planning has the potential to benefit biodiversity across many trophic levels.

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19.
Summary

Utilizing the narratives of 54 youths and 88 child welfare professionals, this article explores the experiences and lives of gay and lesbian youths in child welfare agencies in three cities—New York, Los Angeles, and Toronto—who have been subject to verbal harassment and physical violence within those systems. The author additionally explores the multiple layers of verbal harassment and violence in both the youths' families and in the foster care system, offering recommendations to social work practitioners interested in creating gay and lesbian affirming environments.  相似文献   

20.
Abstract

This article examines Los Angeles' symbolic relation to the rest of the US, deriving from its multi-layered political, social, economic, racialized and environmental complexity. Metropolitan Los Angeles has become 'a dystopian symbol of Dickensian inequalities and intractible racial contradictions', according to historian Mike Davis. Rather than representing America's modernity, Los Angeles has come to symbolize 'the collapse of the American Century'. Accordingly this article explores the motives of African American writers in representing Los Angeles as a politically and environmentally disastrous living space and a figure for the state of the nation. The value that black writers place upon and celebrate in the multiple range of urban ethnicities is at odds, not only with the class and racialized political and economic hierarchies of the city which oppresses its black residents but also contrary to contemporary dominant models of American citizenship. The article considers work by Chester Himes, Octavia Butler and Walter Mosley and argues that within and without the borders of the US, labels like 'minority' or 'ethnic' literature ghettoize, marginalize and minimize its significance. Yet the work of these authors currently carries the weight of the search for a more ethical and moral sense of responsibility for the state of a nation skidding down the path of increasing inhumanity, injustice and disregard, not only for the majority of its own population but for the majority of the residents of this planet. These works are significant acts of dissent from the perpetuation of injustice in contemporary politics, from the increasing extremes of wealth and poverty, and from the parasitic relation of the US to the environment.  相似文献   

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