RT Journal Article
SR Electronic
T1 Curved flight paths and sideways vision in peregrine falcons (Falco peregrinus)
JF Journal of Experimental Biology
JO J. Exp. Biol.
FD The Company of Biologists Ltd
SP 3755
OP 3763
VO 203
IS 24
A1 Tucker, V.A.
A1 Tucker, A.E.
A1 Akers, K.
A1 Enderson, J.H.
YR 2000
UL http://jeb.biologists.org/content/203/24/3755.abstract
AB When diving at prey straight ahead from great distances at high speeds, a peregrine has a conflict between vision and aerodynamics: it must turn its head approximately 40 degrees to one side to see the prey with maximum visual acuity at the deep fovea of one eye, but the head in this position increases aerodynamic drag and slows the falcon down. The falcon could resolve this conflict by holding its head straight and flying along a logarithmic spiral path that keeps the line of sight of the deep fovea pointed sideways at the prey. Wild peregrines, observed with binoculars, telescopes and a tracking device, did approach prey the size of American robins (Turdus migratorius) and smaller birds from distances of up to 1500 m by holding their heads straight and flying along curved paths that resembled the logarithmic spiral.