Bindi Irwin and Robert Irwin

Bindi and Robert Irwin were made famous by tragedy. Their father, the irrepressible conservationist Steve Irwin, died in 2006 when a stingray pierced his heart. The siblings—who between them have 4.4 million Instagram followers—have proselytized to a whole new generation about the protection and preservation of wildlife. Like their dad, they’re unsnobby. They use social media, TV dancing, animal visits on late-night comedy shows and, since 2018, a new reality-TV series about their lives to get people to do what scientists often can’t: care about the fate of the creatures with whom we share the planet. —Belinda Luscombe