Family:
Soricidae (Shrews)
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Family:
Talpidae (Moles)
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Shrews
& Moles
Shrews,
the smallest mammals, are also important because they represent the most primitive
mammals. Their characteristics most closely resemble primitive mammals that
fossil evidence indicates evolved during the era of dinosaurs. As the name
implies, they feed primarily on insects and other small invertebrates. This
order includes two families, Soricidae, the shrews and Talpidae, the moles.
In Idaho, we have relatively few species.
Soricidae Shrews
Shrews include the smallest known mammals. Because
of their small size they have an extremely large surface area relative to
their body volume. Hence, they lose body heat very rapidly, which requires
an extremely high metabolic rate to accommodate the loss of body heat energy.
They are inactive for only short periods of time, typically feeding and eating
about every 3 hours with rest periods between feeding activity. Because of
this high metabolic rate and voracious appetite, some shrews will eat up to
twice their body rate per day. Shrews typically forage along the surface of
the ground in the duff layer of vegetation for their
food. Some shrews actually use a echolocation to navigate about their
environment. Shrews have a pointed snout, very small eyes, and small ears
which typically are hidden in their fur.
Talpidae Moles
The only mole in Idaho is the Coast mole and it is
only found in the extreme western edge of the state. Moles are larger than
shrews but have shorter tails. They are primarily fossorial, or burrowing mammals.
Like shrews, their fur is short and almost like velvet which allows them to
squeeze through the soil in their burrows in either direction with little
resistance. Moles are very well adapted to burrowing; their front legs have
enlarged feet and claws for digging and are angled outward to accommodate
a "breast stroke" type digging. Their pelvis is very narrow to accommodate
changing directions in their small burrows. Their eyesight is poor, but they
have excellent smell and touch with their snout which enables them to detect
and catch their prey such as earthworms.
Information by Donald
Streubel ©2000.
Page design by Ean Harker ©2000.