Black Grouse Hissing Calls Show Geographic Variability across the Distribution Area.

The black grouse is a species whose population development requires constant monitoring due to a rapidly declining trend, especially in Central Europe. Variability in the voices of geographically separated populations can aid in counting within individual populations. This has been investigated with the black grouse.

Acoustic individuality in the hissing calls of the male black grouse ().

Acoustic individuality may well play a big role during the mating season of many birds. Black grouse () produces two different long-distance calls during mating on leks: rookooing and hissing calls. The first one represents low frequency series of bubbling sounds and the second one represents hissing sound.

Individual-based acoustic variation of the alarm calls in the long-tailed ground squirrel.

Based on their phylogenetic position, Nearctic ground squirrels are closest relatives to the long-tailed ground squirrel even though it has Palaearctic distribution. We aimed to investigate the variability of alarm calls of the long-tailed ground squirrel to test the individual variation in alarm calls. This species is known to produce two types of alarm calls: whistle alarms and wideband calls.