Among the many animals the family used to fill various needs, the turtle, the buffalo, the whale, and the ostrich are especially notable.
One of the first animals the family catches is a giant tortoise. Fritz harpoons the creature, who, in a desperate attempt to escape takes the little boat Fritz is in on a perilous ride. When the capture is complete, the family cooks the flesh of the tortoise to eat, and uses its huge shell to make a pure water tub for cooking and washing linen (Ch.18).
The family later find a young buffalo and its mother. The mother buffalo is killed, her tongue and flesh used as meat, and the skin from her feet kept to later make boots and shoes. The young buffalo is captured and tamed, and trained to be a beast of burden (Ch.24).
On an excursion to another island, the boys find a whale "between sixty and seventy feet long", washed up dead on the beach. After much arduous labor, the family secures blubber to make whale oil, some of the intestines with which to make sacks to store the oil, and strips of tough skin with which to fashion harnesses for the domesticated animals (Ch.38-39).
Perhaps the most interesting animal the family uses is the ostrich. The boys catch and tame the animals, and, using seadog-skins as saddles, train the ostriches to allow them to ride upon their backs (Ch.47).
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