Brolga and Sarus Crane calls
Bird calls fulfill a wide range of communication functions between individuals and groups of the same species, or in interactions with other species. On this page Ozcranes looks at the types of crane calls and their functions, with an intriguing musical connection to violins rather than the obvious impression of ‘trumpeting’ or ‘bugling’ calls. By courtesy of recorders and others, we present a range of Brolga and Sarus Crane calls recorded in Australia that can be played from this page, as well as links to other sites with relevant audio or video examples.
Brolga takes flight, calling (Birds as Poetry) ↑
All crane calls are innate (‘hard-wired’, not learned from others or affected by environment). Some are soft, communicating information over short distances: these include contact, stress and food-begging calls of chicks, and purring sounds made by adults while feeding. In contrast the famous unison call or duet by a mated pair, can be heard 2-3 kilometres away , .
Types of crane calls, their volume and distance
|Contact calls (differ by age)||Short-soft|
|Chick stress, food begging||Short-soft|
|Flight landing and take-off||Long-loud|
|Purrs during flight||Soft-short|
|Unison (‘duet’) and Guard||Long-loud|
|Growl, aggressive with display||Short-soft|
Compiled from references  and 
Trumpets, bugles or violins?
Cranes enhance the volume of long-distance calls with a coiled trachea that resonates in the sternum. Coiled trachea and sternum of male Sarus Crane (from Edward Blyth (1881), The Natural History of the Cranes)
The loud calls are known as trumpeting, or bugling, in fact the International Crane Foundation has a regular magazine called ‘The Bugle’. But is this analogy accurate? Abbott Gaunt and team  examined call function in several species and found that loud calls are produced by a process similar to sound in a stringed instrument, not a wind instrument: violins, not bugles...
The tracheal coils that are embedded in the sternum serve a function analogous to the bridge of a stringed instrument, transmitting the vibrations of a tiny sound source to a large radiating surface, the sternum. The sternum then vibrates against the large internal air reservoir of the avian airsac system. As it has a complex shape, the sternum will have many resonances and will respond to many frequencies; as a solid oscillator, its resonances will not be greatly affected by low density gases. Hence, we suggest that cranes and other birds with enlarged windpipes are more properly analogized with a violin than a trombone.
Young cranes transition from juvenile to adult calls during their first year, with a distinct ‘voice break’ at around nine months, when they separate from their parents before the next breeding season , . The unison call between mated pairs is similar in related species, for example the unison calls of Brolga, Sarus Crane, White-naped Crane and (more distantly) Sandhill Crane, are similar in structure .
Brolga unison call, New South Wales (P Merritt) ↑
Calls on Ozcranes
- Brolga making single calls while walking through swamp, no location details (video, YouTube)
- Brolgas walking and calling, Kinka Wetlands SE Queensland (video, YouTube). Brolgas at 0:0-1:17 mins
- Brolgas in flight, Nyngan, New South Wales (audio, zeno-canto)
- Brolga pair display, Cunnamulla-Eulo Road, southern Qld (audio, zeno-canto)
- Brolgas calling in Wasur National Park, Papua, Indonesia (audio, xeno-canto)
Sarus Crane calls
Sarus Crane unison call in ricefield, Uttar Pradesh, India (K.S. Gopi Sundar) ↑
Calls on Ozcranes
- Sarus Cranes calling near the Curtain Fig, Yungaburra, Atherton Tablelands, far north Queensland (audio, Macaulay Library, Cornell University)
- Indian Sarus Cranes calling and flying in to roost in Uttar Pradesh, India (video, YouTube)
- Indian Sarus unison call at the nest, Keoladeo National Park, Bharatpur (video, YouTube)
 Archibald, George W. (1976). ‘The Unison Call of Cranes as a Useful Taxonomic Tool’. PhD, Cornell.
 Nesbitt, Stephen A., and Richard A. Bradley (1996). ‘Vocalizations of Sandhill Cranes’ Paper presented at the Seventh North American Crane Workshop, Biloxi, MS.
 Gaunt, AS, SLL Gaunt, HD Prange, and JS Wasser (1987). ‘The Effects of Tracheal Coiling on the Vocalizations of Cranes (Aves; Gruidae)’ Journal of Comparative Physiology A 161, no. 1: 43-58.
 Klenova, Anna V., Ilya A. Volodin, Elena V. Volodina, and Kirill A. Postelnykh (2010). ‘Voice Breaking in Adolescent Red-Crowned Cranes (Grus Japonensis)’ Behaviour 147: 505-24
 Swaby, Ray J (1983). ‘Tape Recording Sarus Cranes’ The Bird Observer, no. 622: 93-94