Ungulate prey availability to inform Mexican wolf recovery within its historical range

Abstract The Mexican wolf ( Canis lupus baileyi ) is a keystone subspecies of the southwestern United States and northern Mexico. Its ecological role, long lost, is slowly being reinstated. Reintroduction programs are being implemented and high‐quality habitat capable of sustaining populations of this species has been identified in both the United States and Mexico. However, the availability of adequate prey biomass to support recovery of Mexican wolves has not been directly estimated. We estimated the potential ecological carrying capacity for the Mexican wolf based exclusively on ungulate prey biomass using density estimates derived from camera trap surveys conducted between 2017 and 2019 in high‐quality areas within the species’ historical distribution. Results indicate adequate prey for the recovery of Mexican wolves within high‐quality habitat. In the United States, the potential density estimate is high (21.4–52.7 wolves/1,000 km 2 ) because of the presence and relatively high densities of 3 ungulates: elk ( Cervus canadensis ), mule deer ( Odocoileus hemionus ), and white‐tailed deer ( Odocoileus virginianus ). In Mexico, density estimation varies 5.2–14.3 wolves/1,000 km 2 , with only one ungulate species available as prey, white‐tailed deer. Our calculations are underestimates of wolf carrying capacity because they are based on only ungulate prey, and Mexican wolves are known to have a more diverse diet of smaller prey compared to wolves in northern climes. In both countries, recovery goals for this subspecies appear achievable, with the potential of approximately 1,230–3,100 wolves in high‐quality habitat. Currently, there are 2 reintroduction areas, one in the southwestern United States and one in northern Chihuahua, Mexico. We found that the southern Sierra Madre Occidental, specifically the high‐quality patch in the state of Durango, could be considered as a second reintroduction site in Mexico. Estimations of potential carrying capacity for carnivores, particularly those proposed for reintroduction, are a crucial step in the conservation planning process and in setting achievable objectives.