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Acoustic surveys of bat echolocation calls are an important management tool for determining presence and probable absence of threatened and endangered bat species. In the northeastern United States, software programs such as Bat Call Identification (BCID), Kaleidoscope Pro (KPro), and Sonobat can automatically classify ultrasonic detector sound files, yet the programs' accuracy in correctly classifying calls to species has not been independently assessed. We used 1,500 full-spectrum reference calls with known identities for nine northeastern United States bat species to test the accuracy of these programs using calculations of Positive Predictive Value (PPV), Negative Predictive Value (NPV), Sensitivity (SN), Specificity (SP), Overall Accuracy, and No Information Rate. We found that BCID performed less accurately than other programs, likely because it only operates on zero-crossing data and may be less accurate for recordings converted from full-spectrum to zero-crossing. NPV and SP values were high across all species categories for SonoBat and KPro, indicating these programs' success at avoiding false positives. However, PPV and SN values were relatively low, particularly for individual Myotis species, indicating these programs are prone to false negatives. SonoBat and KPro performed better when distinguishing Myotis species from non-Myotis species. We expect less accuracy from these programs for acoustic recordings collected under normal working conditions, and caution that a bat acoustic expert should verify automatically classified files when making species-specific regulatory or conservation decisions. [ABSTRACT FROM AUTHOR]

It has long been known that human listeners can echolocate a sound-reflecting surface as they walk toward it. There is also evidence that stationary listeners can determine the location, shape, and material of nearby surfaces from reflected sound. This research tested whether there is an advantage of listener movement for echolocating as has been found for localization of emitted sounds. Blindfolded participants were asked to echolocate a 3 × 6 ft wall while either moving or remaining stationary. After echolocating, the wall was removed, and participants were asked to walk to where the wall had been. Results showed that participants were somewhat more accurate with moving than stationary echolocation for some distances. A follow-up experiment confirmed that this moving advantage was not a function of a specific type of training or the multiple stationary positions available during moving echolocation. This subtle moving advantage might be a function of echoic time-to-arrival information. [ABSTRACT FROM AUTHOR]

The article reports on the findings of a research in the U.S. revealing that bats appear to be the main victims of wind turbines. Two species, the hoary or eastern red bats, appear to be particularly affected, with more than 60% of bat carcasses retrieved from wind farms. Wind turbines may have a negative effect on bat populations, as bats are long-lived and females usually only produce one or two offspring per breeding season. It is unclear why bats are unable to avoid turbines. It is speculated that high-frequency noise interferes with the bats' echolocation system.