By Saundra McBrearty
Have you ever stood in awe watching birds fly in the perfect V formation? The flock looks organized, in sync, and intentional as they migrate. Long-winged birds like geese, pelicans, storks, and Sandhill cranes take advantage of this energy saving V formation flight strategy. Watch the video of Sandhill cranes flying in V formation over the Visitor Center at Deer Haven Park filmed this past December by Park Officer Logan Curfman. (1) Sandhill Cranes – YouTube
Flying in V formation makes flight easier for the flock as it saves up to 30% of their energy compared to flying solo. In V formation the birds position themselves to fly just behind, above, and to the side of the bird in front, timing their wing beats to catch a gain in lift and take advantage of wind eddies.
What is a wind eddy? It is a whirl of air created when wind encounters a solid object, in this case, the bird wings, and it sends a slip of air in a different direction. The birds cleverly and carefully position their wingtips and sync their flapping to catch the eddies updraft from the bird ahead. This leads to the classic V formation that many migratory birds adopt when crossing our skies during migration.
Unsurprisingly, the point leader at the vertex of the V occupies the most laborious flight position, and those behind benefit from the leader breaking through the air. Interestingly, birds positioned in the rear of the line save the most energy and have the easiest flight because they benefit from additional lift which increases for each bird in turn. This means that the larger a flock is, the more efficiently they fly together. And a more efficient flock needs to stop less often to feed, and the more ground they can cover during flight.
Birds in V formation change position often to share the gains from the efficient flight locations. Each bird takes turns to fly in the extra lift positions on extended flights so that individuals of the flock expend a similar amount of energy.
Enjoy the video of Sandhill cranes migrating over Deer Haven Park visitor center and listen to their loud, rattling bugle calls. Visit the bird sanctuary at Deer Haven Park to see amazing raptors housed in the Aviary, and warm up in the visitor center open daily noon – 5pm to watch birds feed from the viewing windows.
