Life Sciences Commons^™

Bats Track And Exploit Changes In Insect Pest Populations, Gary F. Mccracken, John K. Westbrook, Veronica A. Brown, Melanie Eldridge, Paula Federico, Thomas H. Kunz

Gary F. McCracken

The role of bats or any generalist predator in suppressing prey populations depends on the predator's ability to track and exploit available prey. Using a qPCR fecal DNA assay, we document significant association between numbers of Brazilian free-tailed bats (Tadarida brasiliensis) consuming corn earworm (CEW) moths (Helicoverpa zea) and seasonal fluctuations in CEW populations. This result is consistent with earlier research linking the bats' diet to patterns of migration, abundance, and crop infestation by important insect pests. Here we confirm opportunistic feeding on one of the world's most destructive insects and support model estimates of the bats' ecosystem services. Regression …

Population Growth Of Mexican Free-Tailed Bats (Tadarida Braziliensis Mexicana) Predates Human Agricultural Activity, A. L. Russell, M. P. Cox, V. A. Brown, Gary F. Mccracken

Gary F. McCracken

Background

Human activities, such as agriculture, hunting, and habitat modification, exert a significant effect on native species. Although many species have suffered population declines, increased population fragmentation, or even extinction in connection with these human impacts, others seem to have benefitted from human modification of their habitat. Here we examine whether population growth in an insectivorous bat (Tadarida brasiliensis mexicana) can be attributed to the widespread expansion of agriculture in North America following European settlement. Colonies of T. b. mexicana are extremely large (~106 individuals) and, in the modern era, major agricultural insect pests form an important component of their …

Brazilian Free-Tailed Bats (Tadarida Brasiliensis) As Insect Pest Regulators In Transgenic And Conventional Cotton Crops, P. Federocp, T. G. Hallam, Gary F. Mccracken, S. T. Purucker, W. E. Grant, A. N. Correa-Sandoval, J. K. Westbrook, R. A. Medellin, C. J. Cleveland, C. G. Sansone, J. D. Lopez Jr., M. Betke, A. Moreno-Valdez, T. H. Kunz

Gary F. McCracken

During the past 12 000 years agricultural systems have transitioned from natural habitats to conventional agricultural regions and recently to large areas of genetically engineered (GE) croplands. This GE revolution occurred for cotton in a span of slightly more than a decade during which a switch occurred in major cotton production areas from growing 100% conventional cotton to an environment in which 95% transgenics are grown. Ecological interactions between GE targeted insects and other insectivorous insects have been investigated. However, the relationships between ecological functions (such as herbivory and ecosystem transport) and agronomic benefits of avian or mammalian insectivores in …