Use of pinyon-juniper woodlands by bats in New Mexico

In recent years, the demand has grown for information on how to conserve bat populations in forested ecosystems. Many researchers have responded with studies of bats in forests, but few have studied bat communities in arid-adapted forest types, such as pinyon-juniper woodlands, which are widespread and abundant throughout the west. In this study, I evaluated the relative use and importance of pinyon-juniper woodlands to bats in west-central New Mexico by comparing bats captured in pinyon-juniper woodlands with those captured in ponderosa pine forest. I compared species richness and relative abundance of bats captured in these vegetation types and evaluated the relative importance of each based on its use as reproductive habitat by females. Bats were mistnetted over stock tanks in pinyon-juniper woodlands for 55 nights during 1995-1997 and in ponderosa pine forest for 22 nights in 1998-1999. Although overall capture rates (bats per net hour) were not different between study sites, more species were captured in pinyon-juniper woodlands. The bat community of this pinyon-juniper woodland was dominated by species typically found in upper elevation forests, but also included species from lower elevation shrublands and grasslands. A greater proportion of females was reproductively active in pinyon-juniper woodlands than ponderosa pine, suggesting that females prefer woodlands for rearing their young or that fecundity rates of females are higher in this vegetation type. Results of this study demonstrate that pinyon-juniper woodlands support abundant and diverse bat communities and provide important summer habitat to reproductive females. Thus, biologists and land managers should plan activities in pinyon-juniper woodlands with greater attention and consideration to bats and their habitat requirements.