Danielle Tepper had always loved dolphins. When she went on vacation to Hawai'i, she knew she had to see them firsthand. Tepper—now a senior editor at the Humane Society of the United States—wanted to do it ethically, so she avoided captive dolphin attractions. Instead, she booked an excursion to...

In a quiet corner of Black Beauty Ranch, on a stone plinth beneath a maple tree, there’s an oval etching of a man and a burro. The man is Cleveland Amory, author and founder of the Fund for Animals, and the burro is Friendly, one of the first animals to call the sanctuary home. The two met in 1980...