Volume 6
Issue 2

The U.S. Fish and Wildlife Service Endangered Species Recovery Team for bats was hosted by BCI in Austin in early April. Sixteen experts discussed a wide range of conservation initiatives, status surveys and further research needs for endangered bats in the United States.

Endangered Gray bats and Ozark and Virginia big-eared bats are stable or increasing in numbers. Of the three, the Gray bat has markedly increased its numbers, apparently a direct result of reduced disturbance of cave roosts brought about by protective gates, signs, land owner and caver cooperation. Education appears to be playing a key role in the increase of all three of these year-round cave dwellers after decades of steady decline. Prior to conservation efforts, Gray bats were declining at an alarming rate throughout most of their range.

Population changes in Gray bats at Hambrick, Nickajack and Blowing Wind Caves in central Tennessee and northern Alabama are prime examples of the extent of progress. When BCI’s Science Director, Dr. Merlin Tuttle, gained federal protection of these heavily disturbed sites in the late 1970’s, Hambrick and Nickajack Caves had lost their large nursery colonies, and the Blowing Wind colony had been reduced from a past population likely in excess of a half million to 128,000 bats. Reports presented at the latest recovery team meeting show reestablishment of large nursery colonies in all three caves, with a combined total of 820,000 Gray bats, an overall increase of more than 80%, and up 20% just since 1985 (BATS, December 1986). Protective efforts are responsible for this dramatic success.

Unfortunately, the Indiana bat continues to decline at an alarming rate, despite efforts to date. A 55% decrease has been recorded since 1980, though losses are not geographically uniform. Populations from the Appalachian and Adirondack Mountain areas remained relatively low but stable, while those in the Midwest, where the largest concentrations are located, have continued to fall rapidly.

In the Midwest, Indiana bat losses generally continued in major hibernation caves even where protection had been provided, though there were notable exceptions. Pesticide poisoning and loss of summer feeding and roosting habitat were suggested as possible causes. Procedures for investigating these possibilities were discussed, and federal and state agencies will be asked to fund the needed studies. An early priority will be to compare pesticide levels in bats from stable populations with those from declining populations.

The Gray bat population at Nickajack Cave in Central Tennessee is now recovering due to the protection offered by a fence, wich keeps potential explorers out. PHOTO BY J.R. JORDAN