Examples of USGS Bat Research
Image 1: This passive acoustic recording device has been deployed in Montana (MT) as part of the North American Bat Monitoring Programs (NABat) summertime survey efforts. It has an ultrasonic microphone placed at the top of a 10ft pole that records echolocating bats from sunset to sunrise. The high frequency recordings are used to identify the bat species. USGS scientists at the Northern Rocky Mountain Science Center are working with Montana Fish, Wildlife, and Parks on statistical research for modeling the acoustic data and assessing impacts of Whitenose Syndrome on Montana bat populations. The acoustic devices can often be found on the property of citizen scientists participating in Montana NABat survey efforts. In Montana, the program has collected acoustic data since 2020 and the project has been highly successful! NABat partners with Montana Fish, Wildlife, and Parks send out reports and letters informing them what species were detected and information on those species. This encourages participating landowners to “discuss their bats with their neighbors”!
Image 2: Mexican free-tailed bats that emerged from Bracken Cave in Texas fly among the trees in the early evening sky. Bats are the only flying mammals that are active mostly at night and occur on all continents except Antarctica. Bats are ecologically diverse, with a range of species that specialize in feeding on fruit, nectar, blood, fish, small mammals, and insects. However, of the more than 1,100 known species of bats on Earth, the majority specialize in feeding on insects. In the United States for example, of the 45 different species of bats, 42 are insectivorous. These small creatures of the night are diverse in shape and size, with most relying on echolocation to detect insect prey and find their way through darkness. Many of these bats form colonies that feed on seasonally available insects from spring to autumn.
Image 3: This spotted bat, native to western North America, is a hibernating insect-eating bat that may be at risk as the disease white-nose syndrome (WNS) moves westward. During the winter of 2006–2007 WNS began devastating colonies of hibernating bats in a small area around Albany, New York. Colonies of hibernating bats were reduced 80–97 percent at the affected caves and mines that were surveyed. Since then, millions of insect-eating bats in 38 states and eight Canadian provinces have died from this devastating disease. Bat population declines are expected to have substantial impacts on the environment and agriculture. Bats eat insects that damage crops and spread disease. Consumption of insects by bats saves farmers billions of dollars in pest control services annually.
Image 4: Many of the 47 species of bats in North America migrate in the spring and fall to reach roosting and breeding areas. USGS scientists are studying how tall structures such as wind energy turbines affect some tree bats that make long migrations to overwinter in more southerly latitudes or coastal regions where they have been observed flying offshore during spring and fall migration periods. To help assess the potential risk to bats from planned offshore wind energy, researchers tracked bat movements using acoustic recorders placed on structures such as lighthouses on Virginia’s barrier islands. Researchers noted that bat visitation offshore or to coastal barrier islands at night is associated with lower wind speed and higher temperature and visibility, and visitation varies seasonally (True and others, 2021). These findings were used to develop a tool to predict occurrence of bats at potential future offshore wind sites. This information can help the offshore wind industry plan for strategies to minimize collisions with bats flying offshore.