Sumatra Water Shrew

The Sumatra Water Shrew (Chimarrogale sumatrana), also known as the Asiatic or Oriental Water Shrew, is a very small insectivorous mammal. Currently listed as critically endangered by the International Union of Conservation of Nature (IUCN), the Sumatra Water Shrew is in danger because of the very specific area that it lives in and its habitat being destroyed. These shrews are found in the Sundaland Biodiversity Hotspot, which is the home of 13 critically endangered species and 82 threatened species. Shrews are some of the smallest mammals on the planet.

The Sumatra Water Shrew is only found in the Padang Highlands, which is on the island of Sumatra in Indonesia. These shrews, true to their names, spend much of their time in the water. They even live in burrows with the entrance underwater. They are usually found in streams in mountainous tropical rainforest areas. It is still uncertain as to the status of the Sumatra Water Shrew, as many experts don’t consider them a separate species but rather a subspecies of the Borneo Water Shrew.

Sumatra Water Shrews are very adapted for their lives in the water. All Asiatic Water Shrews are considered large for their species, reaching full adult lengths of 3-5 inches (80-135 mm) with a tail about 2-5 inches (60-126 mm) long. The fur is dark brown in color, very thick, and water repellant, the eyes are very small, and the ears have a flap that seals them when the shrew is swimming underwater. Their feet are fringed with long, stiff, bristly hairs, and this is a characteristic that is only found in water shrews. These fringes help the shrews when they are swimming by increasing water movement.

Did You Know? The fringes on the Sumatra Water Shrew’s feet trap air bubbles between them, which float and allow the shrew to literally walk on water, running across the surface.

Sumatra Water Shrews are insectivores, and they eat many invertebrate animals, including insects and crustaceans. They have also been known to eat insect larvae and small fish. There is also some evidence that they are able to walk along the bottom of a river or stream, hunting and eating the bottom-feeding animals that are found there. Most shrews have very fast metabolisms and, therefore, must eat incredibly large amounts. Because of this, they are constantly active throughout the day and night on their hunt for sustenance.

Little is known about the mating and reproductive habits of the Asiatic Water Shrews, possibly because of the hidden, underwater entrances to their burrows. North American water shrews, which have many of the same characteristics as the Asiatic shrews, can reach sexual maturity as early as three months of age for the females. Males reach maturity in the winter of their first year. The gestational period is generally between 13 and 28 days, and litters are produced that typically have five to seven young shrews. The average life span is only 18 months, and females will often produce up to three litters in their lifetimes.