Flying in a flock comes at a cost in pigeons

Nature. 2011 Jun 22;474(7352):494-7. doi: 10.1038/nature10164.


Flying birds often form flocks, with social, navigational and anti-predator implications. Further, flying in a flock can result in aerodynamic benefits, thus reducing power requirements, as demonstrated by a reduction in heart rate and wingbeat frequency in pelicans flying in a V-formation. But how general is an aerodynamic power reduction due to group-flight? V-formation flocks are limited to moderately steady flight in relatively large birds, and may represent a special case. What are the aerodynamic consequences of flying in the more usual 'cluster' flock? Here we use data from innovative back-mounted Global Positioning System (GPS) and 6-degrees-of-freedom inertial sensors to show that pigeons (1) maintain powered, banked turns like aircraft, imposing dorsal accelerations of up to 2g, effectively doubling body weight and quadrupling induced power requirements; (2) increase flap frequency with increases in all conventional aerodynamic power requirements; and (3) increase flap frequency when flying near, particularly behind, other birds. Therefore, unlike V-formation pelicans, pigeons do not gain an aerodynamic advantage from flying in a flock. Indeed, the increased flap frequency, whether due to direct aerodynamic interactions or requirements for increased stability or control, suggests a considerable energetic cost to flight in a tight cluster flock.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acceleration
  • Animals
  • Biomechanical Phenomena
  • Body Weight
  • Columbidae / anatomy & histology
  • Columbidae / physiology*
  • Energy Metabolism*
  • Flight, Animal / physiology*
  • Geographic Information Systems
  • Models, Biological
  • Social Behavior*
  • Time Factors
  • Wings, Animal / physiology