Near infrasound in birds

Not sure if this has ever been recorded before but during the fights between two male cranes I heard them panting and utter almost infrasound growls (80 to 200 Hz). These calls were not made by the wings. Has anyone heard these before?
Huddunge, Uppland. April 9, 2024

AudioTechnica BP4025 + Zoom F3

Near infrasound in Cranes fighting

This is quite a rare recording where the infrasound of the lekking male capercaillie is clearly audible. This infrasound is thought to be an indication of male quality and the two bands of 35 Hz and 55 Hz probably travel much longer in the forest than the rest of lek. When males utter their infrasounds just after the "plop" they go temporarily deaf so it must be quite exhausting to produce. The males go directly under my microphone and the "crisp" sounds are from dry reindeer moss.

Skogstibble. April 21, 2023.

Mixpre 3ii + AudioTechnica BP4025

Infrasound in lekking Capercaillie

I continue my quest to document near infrasound calls in different bird species (cranes, capercaillies). In this recording you can first hear the male deliver food to the begging female at nest. And directly after (starting at 50 seconds and continuing for the rest of the recording) the male (?) continues with very low-frequency calls (60-80 Hz). 
May 4, 2024, Uppland.

Mixpre 3ii + Lewitt 440 pure in ortf

Near infrasound in Great Grey Owls

Fifth year in a row on different Capercaillie leks. This year started out slowly at 04.10 AM and about 5 males were displaying without much enthusiam until 07.30 when four females arrived. All of a sudden I had 15 males in front of the hide! Where did they come from. Wonderful recordings of the (almost) infrasound (32 Hz) when the males go "blind". If you listen carefully you will also hear mating of Pygmy Owl and hear when the Capercaillie males go quiet when a Goshawk calls in the distance.

Uppland. April 17, 2025.
Zoom F3 + AudioTechnica BP4025

Capercaillie lek with infrasound

Field sound recordist and archivist of vanishing sounds in natural Iandscapes. Highly commended in the Sound of the Year Awards 2024 - Best Natural Sound.

Near infrasound in birds

Bo Söderström