Evidence of resident jaguars (Panthera onca) in the southwestern United States and the implications for conservation

Abstract

Jaguars (Panthera onca) remain virtually unstudied in the desert environments at the northern extent of their range. Historic sightings from the United States indicate a declining population of resident jaguars from the late 1800s into the 1940s, after which only occasional jaguars were reported until the present. After 2 sightings of jaguars in 1996, we established a camera monitoring program in southeastern Arizona. From March 2001 to July 2007, we maintained 9-44 trail cameras and conducted opportunistic track surveys. We documented 2 adult males and a possible 3rd unidentified jaguar with 69 photographs and 28 sets of tracks. One jaguar, originally photographed in 1996, was resighted 64 times during 2004-2007. This ≥13-year-old male used habitats from the Sonoran lowland desert at 877 m above sea level to pine-oak woodlands at 1,577 m, and covered 1,359 km2 in 2 mountain complexes. Despite speculation that recent sightings of jaguars in the United States represented dispersing transients on sporadic forays from Mexico, we documented jaguars in Arizona frequently, continuously, and year-round, and videotaped several scent-marking behaviors, indicating the residency of adult jaguars within Arizona. We outline the importance of maintaining cross-border connectivity for long-term survival of the wide-ranging and thinly distributed binational population of jaguars. We recommend further research and we stress the fragmentation consequences of the proposed United States-Mexico border fence to the northernmost jaguar population, and particularly to jaguars in the United States. © 2008 American Society of Mammalogists.