Habitat Fragmentation and Snakes in Southern California

Powers, Andrew

Karels, Tim J.

California State University at Northridge

Northridge, CA USA

Los Angeles is one of the largest urban areas in the world, and this rapid urban sprawl has created many scattered habitat fragments. These habitat fragments can have negative consequences on wildlife diversity and dispersal. Studies of habitat fragmentation have focused on lizards, mammals and birds, but rarely snakes. Many of these groups, such as lizards, have been chosen for their high visibility and conspicuous nature. Studies have shown that in areas of high fragmentation and urbanization, lizard diversity becomes lower than in unfragmented areas. However, this trend might not carry across all reptile groups. Snakes are an ecologically important group as primary predators on rodents and nesting birds in areas that other predators cannot reach. They are long-lived, habitat specific, and are more vulnerable to human interference than other reptiles. I will explore the relationship between snake diversity and habitat fragmentation in Thousand Oaks, California. I will capture snakes, identify species, and will record mass, length and sex in order to quantify snake diversity and population composition in 25 large and small patches. I expect to find differences in snake composition for patch size because many species are selective in their preferred microhabitat and prey choice. In addition, I expect large snake diversity and size will decrease as patch size decreases. I also hypothesize more recently fragmented patches will have higher diversity compared to older patches. My study will be the first to examine the indirect effects of habitat fragmentation on snake diversity in Southern California. My research will help reveal the challenges local wildlife are faced with through urbanization so that we are better equipped to protect them.