Strong hurricanes are known to reduce population sizes of birds and bats on oceanic islands. Currently unknown, however, is whether these population losses include a loss of genetic diversity in island populations. This study will document the genetic effects of three strong Caribbean hurricanes in September 2004 on populations of three species of West Indian bats. Its basic hypothesis is that strong hurricanes reduce genetic diversity in bat populations and that plant-visiting species will suffer more than insectivorous species. Modern DNA techniques involving both mitochondrial and nuclear genes will be used to document and compare genetic diversity in pre- and post-hurricane samples from two species on Grand Cayman, which was devastated by Hurricane Ivan, and one species on Grand Bahama, which was damaged by Hurricanes Frances and Jeanne. Pre- and post-hurricane genetic samples from two of these species on Exuma, Bahamas, will be used as a control for storm effects; Exuma was not damaged significantly by Frances and Jeanne.
This study will be the first to explicitly document the genetic consequences of strong storms on island vertebrates. Loss of genetic diversity as a result of hurricanes reduces the evolutionary potential of island species and puts them at substantial risk of extinction. Loss of plant-visiting bats on islands, in turn, could cause reduced plant reproductive success via reduced pollination and seed dispersal. Loss of insect-eating bats could lead to increased insect pest problems on islands.
