scienceUpdated: Jul 18, 2020 09:13 ISTPerched on a flowering shrub on a windy Andean mountainside, the tiny Ecuadorian Hillstar hummingbird chirps songs of seduction that only another bird of its kind can hear. That’s considered “ultrasonic” for birds, which generally can’t hear above 9 or 10 kilohertz. For the new study, scientists climbed into the Ecuadorian Andes to reach high grasslands called paramos and locate the Hillstars’ breeding grounds. Humans can hear pitches up to about 20 kilohertz, but lose sensitivity to high-pitch sounds with age. During fieldwork, the younger scientists could usually hear the Hillstar hummingbird songs, but the older participants couldn’t, Duque said.

Source: Hindustan Times July 18, 2020 03:22 UTC