Acoustic Monitoring

Acoustic monitoring is conducted along the LCR using bat detectors. Bat detectors record the echolocation calls of bats and download them to an external storage drive. Different species give different echolocation calls and these calls are identified to species with the help of computer software. This allows us to determine where LCR MSCP bat species occur and what their activity levels are in each of these areas. The following are LCR MSCP bat species:

• California leaf-nosed bat
• Townsend’s big-eared bat
• Western red bat
• Western yellow bat

Currently, acoustic monitoring is conducted at two scales. System-wide acoustic monitoring is conducted through a cooperative agreement with Arizona Game and Fish Department’s Research branch. They are collecting and analyzing data from four long-term acoustic stations that are located within different reaches of the river. The data also allows us to see if these species are distributed evenly across the LCR MSCP planning area, or if they are concentrated in certain areas. This information allows us to better manage for bats when creating habitat.

Post-development acoustic monitoring is conducted specifically at habitat creation areas to determine if LCR MSCP bat species are utilizing the habitat. Other areas nearby the created habitat, such as agricultural fields and non-native saltceder stands were simultaneously monitored to determine if bat activity is higher in the created habitat. Preliminary data shows that some bat species, including the western red bat and the western yellow bat, have higher activity within the created habitat compared to the others. The different aged patches of created habitat are being monitored as well to discover if bats utilize these areas differently. Long term acoustic stations were also set up at four habitat creation areas. In 2011, a pilot study began to determine the feasibility of conducting driving acoustic surveys within LCR MSCP habitat creation areas. Acoustic data is also collected during capture surveys, enabling additional reference files of known bat calls to be collected when bats are released.

For additional information on this project, please refer to Work Task D9: System Monitoring and Research of Covered Bat Species (PDF) and Work Task F4: Post-Development Monitoring of Covered Bat Species (PDF). Find Technical Reports for this Work Task here.

Updated October 14, 2011