1) “Seven Worlds, One Planet” finale, 9 p.m. ET, BBC America and IFC; 9 p.m., AMC and Sundance; also, 12:30 a.m. ET, BBC America. Most nature shows start in Africa; this gorgeous seven-parter ends there. We see chimps fashioning hammers to crack nuts … And a cheetah team (shown here) with a well-plotted attack … And tiny birds living on giraffes, to feast on fleas and ticks. There’s also grim news about poachers and about reduced habitat; David Attenborough, 93, meets the only two survivors from a rhino sub-species.
2) “Saturday Night Live,” 11:29 p.m., NBC. John Mulaney was an “SNL” writer for six years, working well with others. With Bill Hader, he created the Stefon character; with Justin Timberlate and others, he wrote an Emmy-winning song. Mulaney went on to create a failed comedy series and a successful stand-up special; he’s also returned to “SNL.” He’ll have hosted in each of the past three years. His music guest, David Byrne, isn’t nearly as much of a regular; this will be his first “SNL” gig in 30 years.
3) “FBI: Most Wanted,” 8 p.m., CBS. After surviving a mass shooting, a young man was radicalized and became an anti-government terrorist. Now the team tries to stop him before he can strike. That’s followed at 9 by “Bull,” defending a young social-influencer whose father controls her money.
4) “Heartland Vets, DVM” finale, 10:03 p.m ET., Nat Geo Wild, rerunning at 1:15 a.m. This series has focused on a likable married veterinary team in small-town Nebraska. In the finale, Ben Schroeder has his patience tested by a young stallion and does an emergency cesarean birth of a heifer. Erin Schroeder sees a beloved basset hound with difficult issues; also, the entire family helps a newborn fawn.
5) And more: It’s a day for live events – coverage of the South Carolina primary on the news channel and sports on two networks. ABC has XFL football (Los Angeles-New York) at 2 p.m. ET and basketball (Rockets-Celtics) at 8:30. Fox has XFL (Seattle-St. Louis) at 5 p.m. ET and soccer (Atlanta-Nashville) at 8:30. Also, cable has college basketball.