Oral Presentations and Performances: Session I
Project Type
Presentation
Project Funding and Affiliations
Panthera, SINAC, OKC Zoo, The Explorers Club, Wild Felid Association
Faculty Mentor’s Full Name
Mark Hebblewhite
Faculty Mentor’s Department
Wildlife Biology
Additional Mentor
Amaia Autor-Cortés, amaia.autor@umconnect.umt.edu
Abstract / Artist's Statement
Coyotes (Canis latrans) are rapidly expanding their range towards South America, potentially threatening the world’s highest canid diversity. A better understanding of their interactions with native species is needed to anticipate impacts. In Costa Rica, native gray foxes (Urocyon cinereoargenteus) likely occupy a similar niche to the coyote newcomer, yet little data exists on their interactions in tropical ecosystems. We hypothesized the two segregate temporally, given preliminary data suggesting high spatial overlap. Camera-trap analysis revealed moderate temporal overlap (Δ4 = 0.57). Detection frequencies varied significantly across diel periods (Chi-square: p < 0.001); foxes were primarily nocturnal, while coyotes were more diurnal and crepuscular than expected. Permutation analysis (10,000 iterations) revealed significant temporal segregation in site use across three temporal scales reflecting scent persistence: untruncated, 14-days, and 7-days. At the untruncated scale, observed medians for time-to-encounter were longer than chance for coyote-then-fox (observed: 27.4 days; expected: 16.8 days) and fox-then-coyote (observed: 26.0 days; expected: 12.0 days), though given the large delays at this scale, results may reflect factors beyond avoidance. The effect was strongest at the 7-day scale for coyote-then-fox (observed: 3.78 days; expected: 1.38 days) and fox-then-coyote (observed: 3.15 days; expected: 1.08 days), suggesting mutual avoidance of recently visited sites. While activity patterns moderately overlap, the two species may maintain coexistence through mutual avoidance and diel segregation. Behavioral adjustments imposed on gray foxes may represent a stress cost that foreshadows disruption to native canid communities as coyotes advance toward South America.
Category
Life Sciences
Temporal Avoidance By Gray Foxes Reflects Growing Pressure from Expanding Coyotes in the Neotropics
UC 327
Coyotes (Canis latrans) are rapidly expanding their range towards South America, potentially threatening the world’s highest canid diversity. A better understanding of their interactions with native species is needed to anticipate impacts. In Costa Rica, native gray foxes (Urocyon cinereoargenteus) likely occupy a similar niche to the coyote newcomer, yet little data exists on their interactions in tropical ecosystems. We hypothesized the two segregate temporally, given preliminary data suggesting high spatial overlap. Camera-trap analysis revealed moderate temporal overlap (Δ4 = 0.57). Detection frequencies varied significantly across diel periods (Chi-square: p < 0.001); foxes were primarily nocturnal, while coyotes were more diurnal and crepuscular than expected. Permutation analysis (10,000 iterations) revealed significant temporal segregation in site use across three temporal scales reflecting scent persistence: untruncated, 14-days, and 7-days. At the untruncated scale, observed medians for time-to-encounter were longer than chance for coyote-then-fox (observed: 27.4 days; expected: 16.8 days) and fox-then-coyote (observed: 26.0 days; expected: 12.0 days), though given the large delays at this scale, results may reflect factors beyond avoidance. The effect was strongest at the 7-day scale for coyote-then-fox (observed: 3.78 days; expected: 1.38 days) and fox-then-coyote (observed: 3.15 days; expected: 1.08 days), suggesting mutual avoidance of recently visited sites. While activity patterns moderately overlap, the two species may maintain coexistence through mutual avoidance and diel segregation. Behavioral adjustments imposed on gray foxes may represent a stress cost that foreshadows disruption to native canid communities as coyotes advance toward South America.