The importance of atmospheric attenuation for the echolocation of bats (Chiroptera)

摘要: Abstract Atmospheric attenuation of high frequency sound in air limits the effective range bats' echolocation. Attenuation is proportional to squared, but also increases with absolute humidity, passes through a peak, and declines again. The humidity causing maximum very low at 1 kHz, shifts progressively higher humidities ultrasonic frequencies, by 100 150 kHz peak located levels found tropical rain forests. adaptive advantages various frequencies for an echolocating bat are thus dependent. This may explain use 8 4 orientation sounds unidentified insectivorous Amazon Valley.