Hoary bats (Lasiurus cinereus) exhibit continental patterns of migration that are unique to bats, but details about their behaviors during migration are lacking. We captured 177 hoary bats in spring and early summer 2002 as individuals migrated through the Sandia Mountains of north-central New Mexico. Our results support earlier observations of asynchronous timing of migration between sexes of L. cinereus during spring, with females preceding males by ca. 1 month. We provide the first evidence that hoary bats may travel in dispersed groups, fly below the tree canopy along streams, and feed while migrating during the spring. Analysis of guano revealed that the diet of L. cinereus consisted mostly of moth, with more than one-half of samples identified as Noctuidae and Geometriae. We observed a late-spring decline in consumption of moths that might be related to seasonal changes in abundance of prey, differential selection of prey by bats, or sampling bias. We suspect that spring migration of L. cinereus through New Mexico temporally coincides with the seasonal abundance of moths.
New locality for Euderma maculatum (Chiroptera: vespertilionidae) in New Mexico
Perry, T.W., P.M. Cryan, S.R. Davenport, and M.A. Bogan
Three species of nectar- and pollen-feeding bats unique to the southwestern United States may be critical to the health and maintenance of ecosystems in the U.S./Mexico borderland area. The lesser long-nosed bat (Leptonycteris yerbabuenae) and greater long-nosed bat (Leptonycteris nivalis ) are endangered; the Mexican long-tongued bat (Choeronycteris mexicana) is noted by some as being a species of concern. All three species may be jeopardized by vandalism and destruction of roosting sites and loss of habitat and food resources. The Bureau of Land Management needs updated information on nectar-feeding bats as a part of their conservation activities in southwestern New Mexico. FORT researchers are completing studies on the distribution, abundance, and activity patterns of the two species of long-nosed bats in southern New Mexico. Of considerable interest is the recent discovery of a significant new roost on BLM lands, containing the largest aggregation of these bats found to date in New Mexico.