Whiffling is a term used in ornithology to describe the behavior whereby a bird rapidily descends with a zig-zagging, side-slipping motion. Sometimes to whiffle, a bird flies briefly with its body turned upside down but with its neck and head twisted 180 degrees around in a normal position. The aerodynamics which usually give a bird lift during flying are thereby inverted and the bird briefly plummets toward the ground before this is quickly reversed and the bird adopts a normal flying orientation. This erratic motion resembles a falling leaf, and is used to avoid avian predators or may be used by geese (family Anatidae) to avoid a long, slow descent over an area where wildfowling is practised.
The behavior is seen in several species including lesser yellowlegs (Tringa flavipes), the black-tailed godwit (Limosa limosa), the northern lapwing (Vanellus vanellus), geese (e.g. pink-footed goose (Anser brachyrhynchus)), three species of scoter (Melanitta), and other members of the family Anatidae.
- Ogilvie, M.A. and Wallace, D.I.M. (1975). "Field identification of grey geese". British Birds. 68: 57–67.
- Ceurstemont, S. (January 25, 2012). "Goose flying upside down captured in slow-mo movie". New Scientist TV. Retrieved April 19, 2017.
- Weaver, Pete (1981). "Whiffling". The Birdwatcher's Dictionary. Calton [GB]: T. & A.D. Poyser. ISBN 0-85661-028-3.
- Humphries, D. A.; Driver, P. M. (1970). "Protean defence by prey animals". Oecologia. 5 (4): 285–302. doi:10.1007/BF00815496.