Uses
Tusks have a variety of uses depending on the animal. Social displays of dominance, particularly among males, are common, as is their use in defence against attackers. Elephants use their tusks as digging and boring tools. Walruses use their tusks to grip on ice and to haul out on ice. The presence of a tusk in only the male narwhals suggests that for these whales the tusk is a secondary sex characteristic.
Tusks are used by humans to produce ivory, which is used in artifacts and jewelry, and formerly in other items such as piano keys. Consequently, many tusk-bearing species have been hunted commercially and several are endangered. The ivory trade has been severely restricted by the United Nations Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).
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