Why do cranes dance?
Dancing is emblematic of cranes. For birds that are usually cautious and often secretive, dancing draws attention and furthermore it is energy-expensive. Dancing is frequent in the lives of cranes because it establishes social relationships, announces teritorial claims, cements decades-long pair bonding, and hastens the education of the young. It looks like fun and, sometimes, it may be play.
Dancing has long capitivated human observers. Nerissa Russell and Kevin McGowan of Cornell University believe that Neolithic peoples imitated the dances of cranes as part of marriage rituals in the village of Çatalhöyük in Turkey at about 6500 BC (Antiquity, 2003, cited below).
For cranes, graceful and forceful dancing springs from nature and nurture; genes are important but so is learning. For each species, the basic postures and the style of the dance and have genetic bases. However, details of the steps of a display, use of dramatic plumage, and choreography differ among species. Males are generally more dashing and females more reserved, yet both participate vigorously and respond powerfully. On another webpage, we have offered a preliminary dictionary of Sandhill Crane dance steps.
Dances like those between Roy and Millie and other pairs on their nesting grounds are the true dance symphonies. Each of individual dance step and posture is isolated in our Display Dictionary and can be seen in context through the Photo Galleries sidebar. We hope to collect repertoires of more individuals so that we can better dissect dance substrucure, recognize common elements, categorize variations, and perhaps investigate cultural transmission.
Nerissa Russell and Kevin J. McGowan, 2003. Dance of the cranes: Crane symbolism at Çatalhöyük and beyond. Antiquity 77:445-455. [Please note: this is a large pdf file.]
See also Cornell news release.
- Dance involves training
- Dance communicates emotion
- Dance and bird song
It takes time to learn to dance well.
"Display and Dance" is a core subject in the early education of crane colts (see Dance school and Roy's tour jeté in photo galleries). As young cranes watch adults, they display, reprogram, and refine. The postures are incorporated into steps which become dances.
Prowess in dance improves with practice. The dances of yearling cranes in their staging areas (like the shallows of the Platte River in Nebraska) are enthusiastic, athletic, emergent, and strongly tinged with dominance and aggression. The springtime dances of long-established pairs, meters away from those exuberant yearlings, are likewise spirited by also smooth and mutually responsive.
We suspect that one of the major challenges facing yearlings and other sub-adult cranes is to learn to dance with precision because dance is a cement for crane social structure. Without skillful commication through dance, pair bonding is likely to be problematical.
Dance reflects mood and mood influences dancing.
- On the spring day that Roy and Millie return from migration, they dance with great gusto (See link). In some years, Roy dances briefly in the early evening of the day that the eggs have hatched. In these contexts, dance reveals an emotional high.
- Roy and Millie dance in the first week on the nest territory but not during incubation. Dance helps synchronize reproductive effort.
- Family dancing (with colts) starts in July and August during years when there was a healthy young colt (2004, 2006, 2009, 2010) or when no colt had survived (2005 & 2007). Dance is physical trainin g but also perhaps builds enthusiam for colt schooling.
- Roy and Millie stopped dancing in mid-July 2008, after Oblio was injured and thus she could not start flight school. In late July and for most of August, Oblio limped and could not run, flap, bound and glide, all prerequisites for flight. In this instance, we think lack of dancing was due to a crane analogue of worry.
Apparently because of Oblio's infirmity, Roy and Millie delayed their southward migration. Roy and Millie Dancing resumed immediately after Oblio's first flight in early September.
There are intriguing parallels between dance and bird song.
- The proclivity to sing or to dance is innate but in many species, the fundamental substrate is plastic - modifed significantly by learning. Young canaries listen, retain the memory of what they heard, and then belt those memories as they practice and improve their songs months later. Young cranes watch closely the dances of their parents, then imitate and initiate in their clumsy first steps, and eventually dance with the parents.
Are learned steps and individual routines passed from one crane to another? If so, does this suggest avian cultural/social inheritance?
- Dance and song are signal systems with hierarchial structure. For passerine song, the sequence is syllable, phrase, song. For dance, the sequence is posture, step, dance.
- We see some dance steps infrequently and in only a few individuals, but our sample size is small. Of course there are differences in inherent athletic ability. But could dance diversity also reflect individual stylistic flourishes? Are these learned from other cranes, perhaps in the pre-reproductive years when young cranes live as groupies?
There are regional dialects in passerine song. We don't know about crane dancing.
- With experience and the proper hardware and software, ornithologists can distinguish individual cranes from one another soley on teh basis of their unison calls. Likewise, the songs of male passerine birds singing are individually distinguishable. We strongly suspect that cranes dentify other individuals by unison calls. Maybe also by dance? Do dance and calls play a role in community structure?
• 2 - First week
• 3 - Incubation
• 4 - Roy's ice dancing
• 5 - Pi hatches
• 6 - Pi dances
• 7 - Dodging Danger
• 8 - Dragonflies
• 9 - Fitness for flight
• 10 - Swim with Dad
• 11 - Dance and fly
• 12 - August flight school
• 13 - Foraging and intruders
• 14 - Pi explores his world
• 15- -Time to migrate