Ospreys Differ in Foot Preference While Carrying Fish
Written by Andy McCormick
Andy McCormick, Volunteer and Former Board President of Eastside Audubon
In a study of Osprey published in Brain and Behavior, Seattle neurologist Michael Doherty, MD and a team of observers learned that over half of the Osprey observed in analysis of online photographs preferred keeping their left foot forward when carrying fish prey. Ospreys capture live fish in spectacular feet first dives into lakes and rivers and then arrange the fish into a head forward position as they fly back to their nest. The team wanted to know if there was a preference among the Osprey for how they carried the fish.
WHICH FOOT IS DOMINANT?
Among humans, skateboarders, snowboarders, and surfers display a preference for one foot forward of the other on their boards. The “conventional” stance has the left foot forward and the right foot back. The right foot forward and left foot back stance is called “goofy” as in a goofy-footed surfer. Most of us have a dominant foot which would become the back foot in a surfing or skateboarding position. But, what about Ospreys?
Ospreys do not always use two feet to carry fish. Many of the photos the team reviewed showed the Osprey carrying prey with one foot. In my brief review of photos of Osprey carrying food at the Macaulay Library the one-foot carry was likely to be with a smaller fish.
STUDY FINDINGS
Four team members reviewed one of four different search engines (Google, Bing, Yahoo, and DuckDuckGo) and combined their findings. They found a 68% to 32% split of left foot forward to right foot forward stance preference among Ospreys. They found no foot preference for one-foot carries. This result compared well with humans. Surfers tend to be 65% left foot forward and skateboarders were 56% left foot forward. Snowboarders, however, were outliers coming in at 66% right foot forward.
IS ONE FOOT BETTER THAN THE OTHER?
Photo by James McNamara / Macaulay Library at the Cornell Lab of Ornithology (ML508059411)
The entire discussion of foot forward preferences and the term “goofy foot” may betray a certain bias against right foot forward as there sometimes can be against left-handedness. However, one reviewer Dylan Heyden suggests that most Australians and some of the world’s best surfers may be goofy foot surfers. Doherty and the team also suggest that foot forward preference, at least in humans, may be more complex, especially among highly talented surfers during direction-shifting maneuvers. As they twist into the wave and then turn back to surf with the wave, they can become regular or goofy footed as the need arises. The team concluded that, like humans, Osprey have some level of lateralized brain function leading to a foot preference when flying with a live fish.
What the study does not show and what we don’t know is if the same Osprey will alter its foot forward preference depending on how the talons grasp the fish in the water. Do they strike with the same foot forward each time or can they switch feet with circumstances? Someone will have to study the same Osprey during multiple captures of fish to see what they can learn to determine this.