BAT MONITORING AT AQUARIUM
July 29, 2016
On a steamy July day, Han Li and Kevin Parker stood beside a large pond on the grounds of the N.C. Aquarium at Fort Fisher and set up sensitive audio equipment. While they kept an eye on the water for signs of a resident alligator, they pointed their equipment toward the sky and made notes.
The men, researchers from the University of North Carolina Greensboro, trusted the equipment would record the nocturnal calls of wild bats and gather important data on local populations.
This is the second year Li has collected data at the Aquarium site for the North American Bat Monitoring Program. Li is the North Carolina Coordinator for the program. In 2015, the equipment detected 354 audio files and five different species of the flying mammals: eastern red, big brown, evening, silver haired, and tricolored.
The special equipment records the high-frequency sounds made by the bats. Humans can detect sounds up to 16 khz, while bats produce sound in a range two to three times higher than humans can hear. The equipment creates a visual record of the sound that allows the researchers to identify the species.
Bats in North Carolina are critically important, especially in regards to agriculture and pest control Li said. Bats feed on many insects that feed on farm crops. Currently, millions of bats around the country are dying from white-nose syndrome.
Li has completed only a preliminary examination of the most recent data from the Aquarium site. Nineyt-six bat recordings were made over a four night period with confirmation of eastern red, evening and tricolored bats. A nearby site in Carolina Beach State Park had more than 2000 bat files during the same 4 nights, with the same species confirmed. That site was not monitored in 2015.
“So far we cannot use [the results] to suggest a declining bat population,” said Li. “But it certainly does suggest the need to keep monitoring.”