【英语时差8,16】同胞争宠（上）

（单词翻译）

 If you grew up with a brother or sister, you probably know what sibling¹ rivalry² is like. For a spotted³ hyena⁴ though, sibling rivalry is a matter of life and death. Spotted hyena mothers usually have twins. They give birth in a private burrow⁵ where the newborns live for the first few weeks of life. By the time the mother moves her offspring from the natal⁶ burrow to the community den⁷ however, there’s a fifty-fifty chance that one of her infants will be dead. What’s more, her children always emerge from their nursery covered with wounds. A look inside the burrow reveals what’s going on. After a long gestation⁸ cycle, newborn hyenas⁹ are remarkably¹⁰ well developed. Like Red Riding Hood’s wolf, they have big, open eyes and full sets of teeth. They won’t hunt for many months to come, so what are these adaptations for?