welcome to the sonoran desert. i mean, this climate does not feel very desert-y.johnny devenanzio (voiceover): and with 100 reptile, 2,000 native plant, 60 mammal, and 350 bird species calling this desert home, its wildlife is as varied as its weather. jessica moreno: we have black bear, cottontail rabbits, pygmy owl, javelina, mountain lion, cougar. johnny devenanzio (voiceover): but as urbanization tears through this 120,000 square mile region-- you have the mountains and the wildlife juxtaposed with sprawling urban communities for highways, freeways, that sort of thing. johnny devenanzio (voiceover): it's up to conservationists like jessica moreno to ensure that the desert remains a safe haven for our four-legged friends. as we grow and build more roads, we're going to lose the wildlife. and as soon as you start to lose species like that, the health of the entire ecosystem fails. and that impacts our air quality, and it impacts our water quality, and other things that we actually really rely on. johnny devenanzio (voiceover): so in an attempt to prevent this an