HABITAT USE BY BATS IN A RIPARIAN CORRIDOR OF THE MOJAVE DESERT IN SOUTHERN NEVADA

We used a combination of capture and acoustic monitoring equipment to examine use of habitat by bats in a desert riparian community in southern Nevada. Each habitat type (riparian marsh, mesquite bosque, riparian woodland, and riparian shrubland) was simultaneously and continuously sampled acoustically in 3- to 5-night increments for 54 nights between June 2000 and January 2001. Fifteen species of bats were detected acoustically, 13 of which were captured using harp traps or mist nets. Five species were not detected frequently enough to be included in statistical analyses. California leaf-nosed bats (Macrotus californicus) and Brazilian free-tailed bats (Tadarida brasiliensis) were generalists, spending equal amounts of time in each habitat. Western yellow bats (Lasiurus xanthinus) and pallid bats (Antrozous pallidus) demonstrated strong biases for riparian woodland over the other habitats sampled. The remaining 6 species spent substantially more time in at least 1 of the 4 habitats. Riparian woodlands accounted for more than 50% of all bat activity, whereas riparian marshes were the least used habitat. High species richness and differences in habitat use by most species emphasizes the importance of a diversity of riparian habitats for bats at the study site. The existence of both native and nonnative habitat may elevate bat species richness and increase the degree of differential habitat use to levels higher than would be expected if only native habitat existed at the study site. Understanding differential riparian habitat use by bats in desert ecosystems may have profound management implications.