Ivalo, Inari,
Finland 68°
38' 36.9" N 27° 31' 23.1" E 17
June 2019
Song/advertising
call uttered in display flight over open birch campsite.
Composed
of two completely different vocalisations: one a muffled,
deep frog-like croaking at 0.73-1.4 kHZ, the other
a much louder, sharp chi-sik
element spanning 3.7-12.1 kHz.
Bialowieza Forest,
Forest, Poland52º
41' 25.0'' N 23º 52' 44.6'' E 29 June 2009, 2110h
Advertising vocalisations from a
roding male flying
a circuit c400 metres in length. High pitched 'chi-sik' phrase
following two to three low pitched (0.6-1.2
kHz)
frog-like notes.