WILDLIFE CORRIDORS ON THE SAN PEDRO RIVER B. Suarez, R. Martinez, O. Diaz, M. Metzler, H. Jones, T. Ashraf, E. Priddis. Undergraduate Biology Research, Cochise Community College, Sierra Vista, AZ. INTRODUCTION: The San Pedro River, located in Southeastern Arizona, is the last free-flowing river in the southwest. It flows north out of Mexico into Arizona and is an important migration route for birds as well as being a highly diverse area for other wildlife. Hundreds of bird species utilize the San Pedro River during their migrations and at least a third of bird species found in the United States call the San Pedro home. Besides the many species of winged animals, around 80 species of mammals are found in or rely on the riparian areas. Many of the bird and mammal species and other animal species are found in very few other places in the United States. The San Pedro River originates in the Mountains of Mexico approximately ten miles south of the border with the United States of America. After crossing into Arizona it flows through semi-arid grasslands and into the Sonoran Desert before merging with the Gila River, east of Phoenix, Arizona. The water that begins in the San Pedro eventually reaches the Colorado River which flows into the Baja of California. The significance of this river to this area becomes even more apparent due to the fact that it is the only local waterway that flows year round. Due to the San Pedro River’s unique combination of geography, diversity, and lack of regulation it has been called the world’s most studied river. This study looks at the role of the San Pedro River as a corridor for wildlife movement in Southeastern Arizona and also seeks to identify corridors used by wildlife to move between the river and other habitats, particularly sky islands. Water in the region is concentrated during certain seasons, peaking during the summer monsoon. Seasonal patterns of corridor use may correlate to the water patterns. PROCEDURE: Species diversity was identified using high output covert infrared detecting camera traps made by Reconyx©. The cameras were deployed at Gray Hawk Nature Center located east of Sierra Vista, Arizona on the San Pedro River. Possible high traffic wildlife paths were identified including washes radiating out from the river. Cameras were stationed in these areas. The cameras were periodically checked, and each picture was renamed based on the date and time and then sorted according to the species present in each picture. Thus far after the initial survey, the two cameras were relocated to a large wash that feeds into the San Pedro River (see map). The wash runs under an abandoned railroad track near the river. It was determined that the wash is a high traffic area for wildlife and would be an ideal place for a camera trap. SPECIAL THANKS: We would like to acknowledge Sandy Anderson, Director of Gray Hawk Nature Center, for her support of this project. She allows us access to Gray Hawk as well as cameras and has an infinite knowledge of the San Pedro River and Southeast Arizona specifically and natural history in general. We would also like to acknowledge the support of CCURI and Cochise College including Beth Kreugar for her support of our undergraduate research program. RESULTS: A sampling of photos from the camera traps are shown here. The species recorded thus far in the study are mountain lion (Felis concolor), bobcat (Lynx rufus), Coues whitetail deer (Odocoileus virginianus couesi), gray fox (Urocyon cinereoargenteus), coyote (Canis latrans), javelina (Tayassu tajacu), raccoon (Procyon lotor), skunk (4 species of skunk including striped (Mephitis mephitis), hooded (Mephitis macroura), hog-nosed (Conepatus mesoleucus), and western spotted (Spilogale gracilis); all but the western spotted skunk have been detected), coatimundi (Nasua nasua), and a number of bird species including turkey (Meleagris gallopavo), and great-blue heron (Ardea herodias). The frequency of sighting for each species was recorded. DISCUSSION: At this point in the study we have mainly gathered preliminary data, recording the species we have encountered thus far and some information about their movement patterns. We have identified areas of further inquiry and documented some interesting pictures. First, the species appear to have different patterns of movement in the wash. The whitetail deer and skunk species seem to regularly navigate the wash. Other herbivores such as the javelina appear to use the wash in more clumped patterns with frequent sightings followed by times of little or no movement in the wash. Carnivores such as gray fox and coyotes have times of intensive activity that is clumped in time. Though mountain lion activity appears sparse in the data shown here, our more recent pictures have shown much more activity and the fact that they navigate the wash both coming and going during the night. We have also documented at least two adult mountain lions moving together and have picture evidence that there is a mountain lion kitten as well. As we gather more data we will document patterns of use in these species as well as whether the San Pedro varies in its importance to wildlife throughout the year as water levels outside of the river rise and fall with the local precipitation patterns. We will identify the importance of natural corridors such as washes and manmade paths for species movement. The ability of wildlife to utilize such corridors to connect protected areas where they can hunt and reproduce away from the influence of man has been documented. These patterns likely exist on the San Pedro River. We also will begin identifying individuals, particularly of mountain lions and skunks, using DNA sampling of scat and tracking along with photo captures. In the end we will discover more about the interaction between the local wildlife and the San Pedro River which gives them life. Coyote (Canis latrans) Hog-nosed skunk (Conepatus mesoleucus) Gray fox (Urocyon cinereoargenteus) Coues whitetail deer (Odocoileus virginianus couesi) Bobcat (Lynx rufus) Mountain lion (Felis concolor) Gray Hawk (Buteo nitidus) Javelina (Tayassu tajacu) Map of study area and camera location Mountain lion (Felis concolor)