Effects of urbanization on resource use and individual specialization in coyotes (Canis latrans) in southern California

Abstract

Urban environments are unique because fragments of natural or semi-natural habitat are embedded within a potentially permeable matrix of human-dominated areas, creating increased landscape and, potentially, habitat heterogeneity. In addition, urban areas can provide diet subsidies for wildlife species in the form of fruiting ornamental plants, trash, and domestic animals. Ecological opportunity in the forms of habitat and food heterogeneity are thought to be important mechanisms in maintaining individual specialization. Identifying which contexts, traits, and mechanisms determine the success or failure of individuals within an urban wildlife population could potentially provide predictions about which populations may succeed in human-dominated landscapes and which may experience local extinction. We used both scat and stable isotope analysis of whiskers to investigate the degree to which coyotes (Canis latrans) utilized anthropogenic subsidies and exhibited individual diet specialization across the urban-rural gradient in southern California. Land use surrounding scat and isotope sample locations was also evaluated to determine the effect of land cover on diet. Human food constituted a significant portion of urban coyote diet (22% of scats, 38% of diet estimated by stable isotope analysis). Domestic cats (Felis catus) and ornamental fruit and seeds were also important items in urban coyote diets. Consumption of anthropogenic items decreased with decreasing urbanization. In suburban areas, seasonality influenced the frequency of occurrence of anthropogenic subsidies with increased consumption in the dry season. The amount of altered open space (areas such as golf courses, cemeteries, and landscaped parks) nearby had a negative effect on the consumption of anthropogenic items in both urban and suburban areas. Contrary to our hypothesis, urban coyotes displayed reduced between-individual variation compared to suburban and rural coyotes. It is possible that the core urban areas of cities are so densely developed and subsidized that wildlife inhabiting these areas actually have reduced ecological opportunity. Suburban animals had the broadest isotopic niches and maintained similar individual specialization to rural coyotes. Wildlife in suburban areas still have access to relatively undisturbed natural areas while being able to take advantage of anthropogenic subsidies in neighboring residential areas. Therefore, areas with intermediate urban development may be associated with increased ecological opportunity and specialization.

Big Cats in the Big City: Spatial Ecology of Mountain Lions in Greater Los Angeles

“…Unfortunately, there are very few studies about urban mule deer generally, or about their movements and habitat use in urban landscapes specifically (Bender et al 2004 If mountain lions are indeed selecting urban edges because of heavy use of those edges by mule deer that are taking advantage of anthropogenic vegetation, then this would be an example of a secondary urban resource subsidy (Dunagan et al 2019). Omnivorous species such as raccoons and coyotes that reach high densities in urban areas Riley 2010, Hadidian et al 2010) can receive a primary urban resource subsidy by directly consuming anthropogenic resources such as trash, ornamental fruit, or pets (Larson et al 2020), and obligate carnivores such as mountain lions or bobcats may benefit indirectly from urbanization if their prey populations are augmented (e.g., bobcats and rabbits; Dunagan et al 2019).…”

“…), or large cats, which have greater energetic requirements and roam over far greater areas even than medium-sized carnivores such as coyotes (Canis latrans), raccoons (Procyon lotor), or bobcats (Lynx rufus), and pose a greater risk of conflict. Large felids are obligate carnivores and do not take advantage of anthropogenic resources (e.g., trash or ornamental fruit), in contrast to coyotes (Larson et al 2020) and black bears (Ursus americanus; Baruch-Mordo et al 2014); therefore, large felids face perhaps some of the greatest challenges for wildlife in metropolitan areas because they require sufficient densities of large herbivore prey. Consequently, there are few populations of large carnivores, and even fewer of large felids, in cities (Bhatia et al 2013, Riley et al 2014.…”

Individual and Temporal Variation in Use of Residential Areas by Urban Coyotes

“…Alternatively, strong seasonal patterns in food availability can result in seasonal dietary shifts toward more anthropogenic food resources (Morey et al, 2007;Larson et al, 2020). Food availability and dietary diversity are lowest for urban coyotes in the winter (Quinn, 1997;Morey et al, 2007).…”

Dietary niche breadth influences the effects of urbanization on the gut microbiota of sympatric rodents

“…insects for A. speciosus and herbaceous plants for M. rufocanus ). This is in contrast to more free roaming animals such as coyotes and birds that have access to a much wider array of micro-habitats within cities and can more readily take advantage of anthropogenic resources thereby avoiding inter-specific competition (Larson et al, 2020;Pagani-Núñez et al, 2019;Phillips et al, 2018).…”

“…This is because urban sites in this study are heavily used parks by local citizens with barbequing and picnics particularly popular activities during late spring to early autumn. Scraps of meat and other food trash were commonly seen throughout the forest fragments during field surveys and may be opportunistically consumed by A. speciosus as an easy energy source (Larson et al, 2020;Pagani-Núñez et al, 2019). However, A. speciosus could simply be consuming more insects as artificial lighting such as street and park lamps increase insect susceptibility to predation by birds and rodents (Owens et al, 2020;Yoon et al, 2010).…”