Decorah Lions Club members learn the truth about bats

Luther College biology professor Dawn Reding dispelled some of the myths about bats in a recent speech to the Decorah Lions.

Bats, you will be glad to learn, do not suck blood and do not harbor any more diseases than any other species of wildlife.  In fact bats serve as pollinators and disperse seeds, help control insect pests and produce valuable fertilizer. 

Reding told about the importance of bats in the development of sonar.  She also said bats are being studied for their secrets of longevity, since they typically live for 30 years.
 
Concern has been raised about the affect of wind turbines on bat and bird populations, so Reding and a group of Luther students have been investigating this issue for the past two years.  Estimates are that 600 to 800 thousand bats are killed each year by wind turbines in the United States or 7 deaths per year per turbine.  Bats seem to be attracted to the turbines and are struck by the spinning blades, the tips of which reach speeds of 170 mph, or are knocked out of the air by the pressure gradient around the tips.

The students searched the area around the Luther wind turbine every day from April through October for dead bats and birds.   No birds were found.  However, the students found 27 dead bats the first year and 35 the second year. 

Reding says the small creatures are difficult to find, especially, in deep grass, and some may have been scavenged by domestic or wild animals, so the number of bats killed by the wind turbine might have been slightly higher.  The majority of the bats killed were of the four species which are native to the Decorah area.  A few were of the three species which migrate through the state.

Reding suspects that the higher than national average of deaths due to turbines is because Decorah has ideal bat habitat.  There are rocky cliffs with caves and crevices, timber, rivers and streams and plenty of insects.

Reding suggested several ways to reduce wind turbine bat mortality--acoustic and visual deterrents and curtailment, or not operating turbines when bats are most active.