Nineteen strangers huddled together, smiling for a group photo. Many had only met that day. But they’d come together for one mission: to rescue over 700 wild animals from a Puerto Rican zoo—closed to the public since hurricanes battered the island in 2017—and a government-run detention center used...

India leaps into his pool, pouncing on a purple plastic egg—his favorite toy, according to his caregivers. After a few minutes, the tiger ambles over to his watering tub. Instead of taking a drink, he plops in and closes his eyes in contentment. Although he’s young—roughly 10 months old on this June...