How do fringed feet help water shrews swim?

The fringed feet of water shrews, such as the elegant water shrew (Nectogale elegans), are specialized adaptations for aquatic movement. These fringes, composed of stiff hairs, serve to expand the surface area of the feet, which allows the animal to push more effectively through the water.1

In addition to providing propulsion, these fringes play a unique role for species like the North American water shrew (Sorex palustris). By trapping air bubbles, the fringes and toe hairs enable the shrew to skitter across the surface of the water. These adaptations, alongside features like webbing, enhance the shrew's agility and efficiency while foraging in aquatic environments.1