The Eurasian Water Shrew (Neomys fodiens), known in Britain as the Water Shrew, has venomous saliva, although it is not able to puncture the skin of large mammals such as humans. Highly territorial, the Eurasian Water Shrew lives a solitary life and is found throughout northern Eurasia from Great Britain to North Korea.
Eurasian Water Shrew Characteristics
The Eurasian Water Shrew is a mouse-sized insectivore with a moderately long pointed snout and a long tail with a distinct keel formed of stiff hairs which serves as a spine providing structural strength in the water. The water shrew has large feet with hairy fringes and small eyes and ears. The water shrews fur is dense, velvety grey dorsally and whitish beneath. The length of its head and body is around 2.8 to 3.8 inches and it weighs around 0.4 to 0.6 ounces. The Eurasian Water Shrew has a tail up to three-quarters as long as its body.
The water shrews fur traps bubbles of air in the water which greatly aids its buoyancy, however, it also requires it to anchor itself if it wishes to remain underwater for more than the briefest of dives.
Eurasian Water Shrew Habitat
The water shrews preferred habitat is aquatic and terrestrial and includes wet forest, streams and marshes.
Eurasian Water Shrew Behaviour and Diet
The water shrew is particularly adapted to aquatic habits. It can live at least 2 miles away from water but usually inhabits stream banks in which it burrows extensively. Entrances are above or below water and tunnels are made narrow to squeeze water from the animals fur. The water shrew is solitary and active day and night throughout the year.
Water shrews swim fast, remaining submerged up to 20 seconds, hunting frogs, fish, snails, mollusks and insects, which it immobilizes with its venomous saliva. The shrew propels itself in the water with its fringed hind feet, using its keeled tail as a rudder. The water shrews ear passage is closed by two valves.
Eurasian Water Shrew Reproduction
Breeding occurs in April through to September, with two or more litters of 3 – 8 young per season. Gestation is around 24 days. The offspring are weaned in about 37 days.