Abert's Towhees (Pipilo aberti) are found in areas of dense vegetation in and around riparian areas and desert washes here in Arizona. I spotted this Abert's Towhee and its mate in a neighborhood along the Tanque Verde Wash here in Tucson.
Abert's Towhees are large, long-tailed, plain brown sparrows, and they can be distinguished from the very similar California Towhees (P. crissalis) and Canyon Towhees (P. fuscus) by their small, black face masks. Male and female Abert's Towhees look alike, and the pairs are usually found together in their breeding range year-round.
Even though they are often found in dense cover and behave rather secretively, I've found that Abert's Towhees, like other towhees, are actually surprisingly tame and will often let you approach them a bit closer than many other wild birds.
Given their drab coloration and fondness for thick vegetation, probably the best way to locate Abert's Towhees is by their sharp, loud, piping calls.