Mallard ducks are capable of performing a wide range of behaviors including nearly vertical takeoffs from both land and water. The hindlimb plays a key role during takeoffs for both; however, the amount of force needed differs in fluid and solid environments. In a new paper in the Journal of Experimental Biology, recent graduate Kari Taylor-Burt (PhD '20) and Prof. Andrew Biewener hypothesize that hindlimb joint motion and muscle shortening are faster during aquatic takeoffs, but greater hindlimb muscle forces are used during terrestrial takeoffs.
Taylor-Burt and Biewener examined the hindlimb kinematics and lateral gastrocnemius (LG), a major ankle extensor and knee flexor, during takeoffs from water versus land in mallard ducks. The researchers saw no change in the ankle; however, the hip and metatarsophalangeal joints (found between the metatarsal bones of the foot and the proximal bones of the toes) showed greater muscle force during land takeoffs. During water takeoffs, they showed almost no motion. The ducks' knees extended during land takeoffs and flexed during water takeoffs.
Because different forces and physical properties are used for water and land takeoffs, animals such as mallards may be challenged to tune their muscles for movement across different environments.
The study also received the coveted cover photo for the issue.