Tenrecs - Family Tenrecidae, Reproduction, Temperature Regulation - Evolution of insectivores
Tenrecs are four-legged nocturnal mammals belonging to the order Insectivora. Tenrecs have evolved into more distinct forms than any other family of animals within the order. Tenrecs can resemble hedgehogs, moles, shrews, or muskrats, depending on the species. Some species of tenrecs have a long tail and long hind legs, while others have a stumpy tail and short hind legs. Furthermore, some species of tenrec have a spiny coat, similar to that of hedgehog, while others have velvety fur.
Within the order Insectivora, there are six general types: shrew type, rat type, hedgehog type, mole type, jeroba type, and otter type. Tenrecs are grouped together with the shrews, and are characterized by an elongated body, and long, pointed snout. Tenrecs belong to the family Tenrecidae.
Evolution of insectivores
Insectivores are the most primitive of all higher mammals, and insectivore-like animals predated all of the orders of today's mammals. The fossil remains of insectivores indicated that they lived during the Cretaceous period. Rat-sized ancestors of today's insectivores date even back further—to the Jurassic and Lower Cretaceous periods. These fossils also indicate that tenrec-like animals and golden moles are related to each other.
Tailless or common tenrec (Tenrec ecaudatus)
The tailless tenrec is, perhaps, the best known species of tenrec. Vaguely resembling a hedgehog, it measures about 12.5 in (32 cm) long, with a stubby tail measuring 0.4-0.6 in (1-1.6 cm) in length. It has a long snout and coarse, bristly fur interspersed with spines. These tenrecs prefer sandier environments, such as highland plateaus and cliffs along riverbanks. During the day, these animals rest in crevices or burrows; at night, they forage for food by digging with their claws and snout. Tailless tenrecs mainly eat insects, lizards, eggs, roots, and fruit. In the dry season, these tenrecs hibernate in deep underground burrows. At the beginning of October, after a long hibernation, they mate. Female tailless tenrecs commonly have as many as 16 surviving offspring.
If threatened, tailless tenrecs stand on their hind legs and bristle their coats, and try to push the bristles into the intruder, while snorting, grunting, and hissing. Although tailless tenrecs are protected by law, the people of Madagascar hunt these animals for their fatty meat.
Rice tenrecs (Oryzorictes spp.)
Rice tenrecs are spinier than tailless tenrecs and, are more closely related to hedgehogs. Rice tenrecs are classified with the shrews because of similarities in their skeletons. The body of rice tenrecs measures between 1.5-5 in (4-13 cm), and their tail measures between 1-6.5 in (3-16 cm). These tenrecs acquired their name because they live on and within the banks of rice paddies, as well as in warm, moist forests, swamps, and meadows. Their front limbs are well adapted for digging and these tenrecs spend a great deal of time underground. Rice tenrecs are only seen above ground at night, but it is assumed that they are very active during the day underground, eating invertebrates and crustaceans. Rice growers in Madagascar consider rice tenrecs to be pests.
- Tenrecs - Family Tenrecidae
- Tenrecs - Reproduction
- Tenrecs - Temperature Regulation
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