Kinematics of the transition between aquatic and terrestrial locomotion in the newt Taricha torosa.

California newts (Taricha torosa) are capable of locomotion in both aquatic and terrestrial environments. The transition between swimming and terrestrial walking was examined by videotaping individual Taricha walking both up and down a ramp, inclined at 15 degrees to the horizontal, that had its lower end immersed in water and its upper end out of the water. When ascending the ramp, California newts first approached it by swimming, then used their limbs to walk while still in water, and finally left the water using a normal terrestrial walking gait. The reverse of this sequence was observed when individuals descended the ramp. In both directions, Taricha used a lateral sequence walk with a duty factor of approximately 76% when out of the water. Timing of footfalls was more variable in water and featured shorter duty factors, leading to periods of suspension. Comparison of angular and timing variables revealed effects due to direction and degree of immersion. Few timing variables showed differences according to stride within sequence (indicating whether the animal was in or out of the water), suggesting that the basic walking pattern is equally good in both environments.