General Overview
The Soricidae family, commonly known as shrews, is one of the largest mammal families, with over 400 species distributed worldwide except for Australia and Antarctica. Shrews are tiny, insectivorous mammals that resemble mice but are not rodents. They are among the smallest mammals on Earth and have incredibly high metabolic rates, requiring them to eat almost constantly. Despite their size, shrews play an important ecological role in controlling insect populations and serving as prey for larger predators.
Appearance
Shrews are small, generally ranging from 3 to 15 cm in length, with slender, elongated snouts and small, beady eyes. They have dense, velvety fur in shades of gray, brown, or black, short legs, and inconspicuous ears often hidden in their fur. Their tails vary from short to relatively long depending on the species. Unlike rodents, shrews have sharp, spike-like teeth rather than gnawing incisors. Some species possess reddish-tipped teeth due to iron deposits, which strengthen them against wear.
Diet
Shrews are voracious insectivores, feeding primarily on insects, spiders, earthworms, and other small invertebrates. Some species also consume small vertebrates, carrion, and plant matter such as seeds or fungi. Because of their high metabolism, many shrews must consume their own body weight in food every day, and going without food for just a few hours can be fatal. A few species, such as the Eurasian water shrew and certain North American species, possess venomous saliva to subdue prey.
Habitat
Shrews occupy a wide variety of habitats, including forests, grasslands, wetlands, tundra, and even deserts. They are adaptable and can be found from sea level to alpine environments. Many live in leaf litter, under logs, or in burrows, while semi-aquatic species are associated with streams and wetlands. They typically construct small nests of leaves or grass for shelter. Their small size and ability to thrive in different microhabitats make them one of the most widespread mammalian families.
Behavior
Shrews are solitary and highly territorial, with individuals often engaging in aggressive encounters. They are primarily nocturnal or crepuscular, though activity can occur at all hours due to their constant need for food. Most communicate through high-pitched squeaks, scent marking, and tactile cues, while some species may use rudimentary echolocation. Shrews breed prolifically, with females producing multiple litters each year. Because of their rapid metabolisms, they have short lifespans, often living less than two years in the wild.
