Small And Strange Shrews are Unique Mammals
Taming of a Shrew may be More Than a Shakespearean Task
Sep 3, 2009
There are more than 280 species of shrew distributed throughout the world with notable absences in Australia, New Zealand, the West Indies and most of South America (Encyclopedia Of Animals: Whitfield, 1998).
Shrews are insectivores and lead most of their lives along the debris of a forest floor or pasture land. Small in size, ranging from one inch to six inches long depending on the type of shrew, they also have many unique characteristics which one may not expect from such a harmless looking creature.
Shrews have a very high metabolism rate, with an average heart rate of more than 1, 200 times per minute. With such a hyperactive lifestyle, the shrew have enormously large, and sometimes unappealing appetites. Some species of shrew are reported to eat their own feces and also the feces of other animals as well. It is thought that by consuming their own waste, the shrew is capable of boosting their intake of Vitamin K and B, which may relate to their hyperactivity.
Along with feces consumption, some shrews also have poisonous saliva which they use to kill small frogs and fish. Along with their diet of feces and venom-killed prey, shrew also may eat carrion, or dead meat, in order to survive and sustain their need for an enormous amount of food relative to their small size of usually less than six inches.
North American Shrews
Two members of the shrew family are unique to the continental United States: the Masked Shrew and the Short-Tailed Shrew.
The Masked Shrew is seen throughout the United States, although it rarely ventures into more arid areas of the deep south. Inhabiting the surface layers of the forest, it is active throughout both day and night, constantly feeding on such invertebrates such as earthworms and snails. Generally solitary animals, the male and female only pair for mating and a litter of up to ten young are born in the spring and summer. Being weaned after one month, the shrews then go about their solitary life once again.
The Short-Tailed Shrew is found in all terrestrial habitats in the Eastern United States. It has two unusual characteristics not normally found in shrews. The Short-Tailed Shrew will sometimes seek out company in other shrews, although this has only been shown in captivity. It also climbs trees in search of food, which other types of shrews rarely, if ever, do. The Short-Tailed Shrew is an important influence on controlling pests in forest vegetation such as sawflies, which it gorges on continuously. Building a grassy nest under a stump or log, the Short-Tailed Shrew will produce three to four litters a year of up to nine young each.
Shrews Throughout The World
Other interesting species of shrews include the Sri Lankan Long-Tailed Shrew, the Pygmy White-Toothed Shrew and the Armored Shrew.
The Sri Lankan Long-Tailed Shrew is found in the forests and savannas of Sri Lanka and is unique in several regards. While dining on the standard shrew diet of invertebrates, the Sri Lankan Shrew also will eat small lizards and young birds. It is able to accomplish this feat in part because it produces strong scent glands that protect itself from many predators. Another unique characteristic of this shrew is that after a litter of young is produced, the young will leave the nest traveling by “train”, gripping each other’s tails in search of food. This habit of the young working together as a group is unique to this type of shrew alone.
The very small, one to two inch in length, Pygmy White-toothed Shrew is unique because it is the world’s smallest terrestrial animal. Weighing only about one-fourth ounce, the shrew is somehow able to not only survive in the grasslands of Southern Europe, Asia and Africa but thrives on ingesting much larger prey including spiders, insects, grasshoppers and cockroaches.
The Armored Shrew of Africa may be one of the most unusual of the shrew species. The armored shrew has a spine which is fortified by a mesh of interlocking bony flanges and rods, a very unique skeletal structure. Some reports have stated that this small shrew, usually four to six inches in length, can support the weight of a full-grown man on its back due to this anomaly.
Shrews are an Example of the Strangeness of the Animal World
By their unsavory eating habits, venomous bites and solitary lifestyle it is easy to see how the term “shrew” came to mean a violent, scolding or nagging temperamental human. It is by understanding and studying the characteristics of such small mammals that we may become develop a better understanding of the quirks of larger animal life, including humans.
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