Individual variation in anthropogenic resource use in an urban carnivore

Abstract

With increasing urbanization, some animals are adapting to human-dominated systems, offering unique opportunities to study individual adaptation to novel environments. One hypothesis for why some wildlife succeed in urban areas is that they are subsidized with anthropogenic food. Here, we combine individual-level movement patterns with diet composition based on stable isotope analysis to assess the degree to which a rapidly growing population of coyotes (Canis latrans) in Chicago consumes anthropogenic resources. We used telemetry to classify coyotes into three groups based on social class and home range composition: (1) residents with home ranges in urban nature preserves; (2) residents with home ranges that had a high proportion of urban land; and (3) transients that had relatively large home ranges and variable use of urban land. We found that natural and anthropogenic resources in this system can be reliably partitioned with carbon isotopes. Mixing models revealed that resident coyotes associated with most urban nature preserves consumed trace to minimal amounts of anthropogenic resources, while coyotes that live in the urban matrix consume moderate (30-50%) to high (>50%) proportions of anthropogenic resources. Lastly, we found evidence of prey switching between natural and anthropogenic resources and a high degree of inter-individual variation in diet among coyotes. In contrast to the expectation that urban adaptation may dampen ecological variation, our results suggest individuality in movement and diet exemplifies the successful establishment of coyotes in urban Chicago. Our study also suggests that direct anthropogenic food subsidization is not a prerequisite for successful adaptation to urban environments.

Space use by resident and transient coyotes in an urban–rural landscape mosaic

“…humans tolerating coyote presence) would make commercial-institutional and housing land cover more attractive to coyotes, but this was not part of this study. Newsome et al (2015) found large individual differences in the utilisation of anthropogenic food, but no general difference between residents and transients.…”

“…In addition, transient coyotes can often be found at the edges of resident territories (Windberg and Knowlton 1988;Kamler and Gipson 2000;Hinton et al 2015). In Chicago, transients tend to have a higher share of urbanised land in their home range than residents (Newsome et al 2015). Because transient resource selection is constrained by residents that defend territories, their selection is less likely to be an expression of the true preference of the species (Kamler and Gipson 2000;Kamler et al 2005;Hinton et al 2015).…”

Coyote (Canis latrans) diet in an urban environment: variation relative to pet conflicts, housing density, and season

“…This technique is better able to discriminate between natural prey items and anthropogenic resources by estimating the isotopic composition of each food item and of coyotes, measured in hair or vibrissae. Previous studies using this method have shown that some coyotes in urban areas will consume anthropogenic food (Murray et al 2015;Newsome et al 2015), and stable isotope analysis can report a higher prevalence of anthropogenic foods in coyote diets than scat analysis. Therefore, if assessing anthropogenic food resources in the urban coyote diet is a primary objective, then future studies should include this technique or others like it (e.g., fatty acid analyses) in conjunction with fecal analysis to obtain a more accurate assessment of coyote diets in urban areas.…”

“…Thus, fecal analysis has limitations for examining the diet of wildlife species in urban environments. Stable isotope analysis is an alternative method that has been used in urban systems to examine coyote diets (Murray et al 2015;Newsome et al 2015). This technique is better able to discriminate between natural prey items and anthropogenic resources by estimating the isotopic composition of each food item and of coyotes, measured in hair or vibrissae.…”

Prevalence, risk factors, and geographical distribution of zoonotic pathogens carried by peri-urban wild dogs

“…Domestic dog food was not detected within this study, suggesting that it is not a significant food resource. Across the globe, human associated food resources are highly utilised by urban vertebrate pests (Contesse et al, 2004;Newsome et al, 2015). Coyotes were found to utilise anthropogenic sources of food when they exhibited signs of illness, however healthy coyotes preferred to utilise natural sources of food (Murray et al, 2015).…”