posted on 2011-12-30, 19:49authored byRune Dietz, Ari D Shapiro, Mehdi Bakhtiari, Jack Orr, Peter L Tyack, Pierre Richard, Ida Grønborg Eskesen, Greg Marshall
Copyright information:
Taken from "Upside-down swimming behaviour of free-ranging narwhals"
http://www.biomedcentral.com/1472-6785/7/14
BMC Ecology 2007;7():14-14.
Published online 19 Nov 2007
PMCID:PMC2238733.
during the third dive of each animal. To dispense with the ambiguity of equal and opposite turns off the central axis, imagine a unit circle coincident with a trans-axial cross-section of the body where 0 and π lie along the right and left sides of the body midline, respectively. The thicker segments in the figure correspond to the roll angle ranging between ±π/2 passing through 0 and the thinner segments to the roll angle ranging between ±π/2 passing through π. The purple and green dots at the bottom of the two panels indicate when the animals were turning clockwise and counter-clockwise, respectively.