Differences between stance and foot preference evident in Osprey (Pandion haliaetus) fish holding during movement.

BACKGROUND: Skateboarders, snowboarders, and surfers all show stance preferences for which foot is forward while moving. We are unaware of other animals than humans with a stance preference, perhaps excepting Osprey, who fly their caught fish beneath them in a foot-forward stance. We hypothesize there should be no difference between left foot forward, right foot back (conventional) versus right foot forward left foot back (goofy) stances or for fish holding with unilateral left or right foot. Online, publicly available, convenience images of Osprey catching fish were accessed and assessed by five independent reviewers using different Internet search engines or online photo series. Stance preference and footedness were tested using chi-square analysis.

RESULTS: Stance preferences were evident with the left foot forward (conventional stance) on average 64-78% of the time (all p < 0.02). No difference in foot preference for either one-foot grabs of fish during flight or for non-flight nest/perch fish holding was evident.

CONCLUSION: Flight stance of Osprey holding fish shows a lateralized preference in a proportion similar to skateboarders of surfers. We discuss stance preferences in the setting of complex movements and potential flight and survival advantages for Osprey.