Coyote and red fox interactions across an urbanization gradient in the Chicago metropolitan area

Cervantes, Alyson M

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https://hdl.handle.net/2142/113896 Copy

Description

Title

Coyote and red fox interactions across an urbanization gradient in the Chicago metropolitan area

Author(s)

Cervantes, Alyson M

Issue Date

2021-12-07

Director of Research (if dissertation) or Advisor (if thesis)

Schooley, Robert L

Committee Member(s)

• Allen, Maximilian L
• Lehrer, Elizabeth W

Department of Study

Natural Res & Env Sci

Discipline

Natural Res & Env Sciences

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• coyote
• red fox
• urban wildlife
• mesopredator
• spatial
• temporal
• species interactions

Abstract

Mesopredators including coyotes (Canis latrans) and red foxes (Vulpes vulpes) often occur in urban environments. However, whether the coexistence of these competing canids is facilitated by spatial and temporal niche partitioning remains unclear. Highly urbanized areas can act as a refuge for red foxes (i.e., spatial human shield effect), allowing them to avoid intraguild predation from coyotes. However, without spatial partitioning, these species may coexist in part through temporal niche partitioning. We used data from an extensive camera-trap array (110 sites) established across an urbanization gradient in the Chicago metropolitan area to examine coyote-fox interactions from 2011 to 2018. We analyzed spatial partitioning by creating single-species, multi-season occupancy models for both species and by using structural equation modeling. We then quantified temporal overlap between coyotes, red foxes, and humans. Site occupancy by coyotes was strongly affected by habitat type as they occurred most often in natural areas. Colonization rates of coyotes also differed among habitat types and were negatively related to urbanization. Urbanization also increased extinction rates for coyotes at sites. Red fox occupancy was negatively impacted by urbanization, but colonization of sites by foxes was not explained by our covariates. Extinction rates for red foxes depended on a surprising interaction between coyote and human photographic rates. When coyotes were rare at sites, fox extinction was related positively to human activity. In contrast, when coyotes were more common, extinction of red foxes was less likely at sites with higher human activity. One hypothesis for this relationship is that a spatial human shield effect might be occurring at a local, within-site scale. The structural equation modeling further supported the negative impact urbanization had on both species, and the lack of a direct effect of coyotes on the spatial distribution of foxes. Diel activity patterns of coyotes and red foxes differed although there was still fairly high overlap. However, temporal niche partitioning intensified at more urbanized sites. Both canids had low overlap in activity with humans. Our results suggest that the spatial human shield effect is currently not operating in the broader Chicago metropolitan area. Coyotes and red foxes may share the same green spaces, especially in highly urbanized areas, where species coexistence is promoted by temporal niche partitioning.

Graduation Semester

2021-12

Type of Resource

Thesis

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http://hdl.handle.net/2142/113896

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Copyright 2021 Alyson Cervantes

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