Born on Monday, July 10, at the Philadelphia Zoo, the female Amur tiger cub was the only survivor in her litter of five; two of her siblings were stillborn, one died from an injury sustained by its mother and another suffered from a critical gastrointestinal issue. Despite being a tiny miracle, Zoya was rejected by her mother, 10-year-old Koosaka — a behavior somewhat typical of first-time tiger moms. So the Philadelphia Zoo’s animal care team jumped in to raise her, bottle feeding her and keeping watch around the clock. However, something was missing — namely, peers. “With this single cub,...