Trophic Cascades and Conservation: Analyzing the San Juan National Forest as a Potential Extension of the Mexican Gray Wolf Recovery Program

Abstract

Fewer than 100 Mexican gray wolves remain in the wild in the US, due to a history of overhunting, predator bounties, and habitat loss; making them the most critically endangered subspecies of gray wolf. The San Juan National Forest (SJNF) of southwestern Colorado seems to be suitable habitat for them due to the physical attributes of the land, and the abundance of prey found within the area. Introducing a small population to the SJNF would allow for the expansion of the subspecies’ range and may help ensure the Mexican gray wolf’s survival by preventing inbreeding from occurring within the population as a result of isolation of the population. An introduction of the Mexican gray wolf in the SJNF would also potentially lead to the slowing of Sudden Aspen Decline (SAD) that is currently being observed in the region, in part due to overbrowsing of young aspen shoots by elk (Cervus elaphus nelsoni), the key prey for wolves. Political and social implications must be taken into account as well, along with possible mitigation for wolf human conflict. This study evaluates the ecological potential for introducing Canis lupus baileyi to the SJNF and intends to better inform the Colorado public and proposing environmental groups of this possibility. Results show that an introduction would benefit the wild Mexican gray wolf population, based off of the results of the Rosenzweig- MacArthur predator-prey model, and through spatial analysis of road density and proximity to the current recovery area. Results also indicate that Sudden Aspen Decline would slow after a certain ratio of wolves per 1000 elk was achieved. More broadly, an expansion of the current recovery plan would solidify that the importance of predators in their ecosystems and have a positive effect on other trophic levels.