Abiotic conditions mediate intraguild interactions between mammalian carnivores

• Published in: Journal of Animal Ecology
• Main Authors: Jensen, Paul G., Humphries, Murray M.
• Other Authors: Fryxell, John, Federal Aid in Wildlife Restoration
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2019
• Subjects: Martes americana
• Online Access: http://dx.doi.org/10.1111/1365-2656.13024; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2F1365-2656.13024; https://onlinelibrary.wiley.com/doi/pdf/10.1111/1365-2656.13024; https://onlinelibrary.wiley.com/doi/full-xml/10.1111/1365-2656.13024; https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/1365-2656.13024

Abstract Intraguild (IG) interactions are common among mammalian carnivores, can include intraguild predation (IGP) and interspecific killing (IK), and are often asymmetrical, where a larger more dominant species (IG predator ) kills a smaller one (IG prey ). According to ecological theory, the potential for an IG predator and IG prey to coexist depends on whether the direct consumptive benefits for the IG predator are substantial (IGP) or insignificant (IK), the extent to which the IG prey is the superior exploitative competitor on shared prey resources, and overall ecosystem productivity. We used resource selection models and spatially explicit age and harvest data for two closely related mesopredators that engage in IG interactions, American martens ( Martes americana IG prey ) and fishers ( Pekania pennanti IG predator ), to identify drivers of distributions, delineate areas of sympatry and allopatry, and explore the role of an apex predator (coyote; Canis latrans ) on these interactions. Model selection revealed that fisher use of this landscape was strongly influenced by late winter abiotic conditions, but other bottom‐up (forest composition) and top‐down (coyote abundance) factors also influenced their distribution. Overall, fisher probability of use was higher where late winter temperatures were warmer, snowpack was deeper, and measures of productivity were greater. Martens were constrained to areas of the landscape where the probability of fisher use, coyote abundance, and productivity were low and selected for forest conditions that presumably maximized prey availability. Marten age data indicated an increased proportion of juveniles outside of the predicted area of sympatry, suggesting that few animals survived >1.5 years in this area that supported higher densities of fishers and coyotes. Consistent with asymmetrical IG interaction theory, the IG predator (fishers and, to a lesser degree, coyotes) competitively excluded the IG prey (martens) from more productive, milder temperature habitats, ...