Water rail
Water rails are omnivorous, although they mainly feed on animals. These include leeches, worms, gastropods, small crustaceans, spiders, and a wide range of both terrestrial and aquatic insects and their larvae. Small vertebrates such as amphibians, fish, birds and mammals may be killed or eaten as carrion. Vertebrates are impaled with a strike of the bill which breaks the prey's spinal cord. Plant food, which is consumed more in autumn and winter, includes the buds, flowers, shoots and seeds of water plants, berries and fruit. In south Asia, paddy (harvested rice kernels) may sometimes be eaten. The young rails are fed mainly on insects and spiders. Food obtained on land or from mud is normally washed in water before it is eaten. After rain, rails may probe soft ground for earthworms. This species will occasionally feed in the open even when not forced to do so by cold weather; Edmund Meade-Waldo described seven rails feeding in an open meadow. Despite its skulking nature, the water rail appears to thrive in captivity when fed on animal food such as raw meat or earthworms; one individual was taught to jump for worms suspended from a fishing rod.
Marsh shrew
The marsh shrew eats invertebrates, including spiders, earthworms, sowbugs, centipedes, termites and other terrestrial and aquatic arthropods. It was observed in captivity pursuing and killing a goldfish, but not eating it. In contrast, the American water shrew has been observed killing and eating fish. A study of the gastric contents of marsh shrews in Oregon indicated that at least 25% of their diet is aquatic, including insect larvae, slugs and snails, mayfly naiads and other, unidentified invertebrates. Other researchers have reported that their diet may also include aquatic insects (water beetles and stonefly nymphs), craneflies, ground beetles, spiders, harvestmen, centipedes, earthworms, slugs and small terrestrial snails. The marsh shrew swims, making short dives in search of food; its mobile snout, whiskers and lips are used to find and capture underwater prey. Before eating, it returns to land. Air trapped in its fur provides buoyancy, and marsh shrews can run for as long as 3 to 5 seconds along the top of the water. According to mammalogist Donald Pattie, they can "scull on the surface like whirligig beetles". The air trapped in its fur gives it a silvery sheen. On land, its foreleg and opposite hind leg move at the same time.