Sunday's Best Bets on TV

"Nature: Vanishing Lions" (7 p.m., PBS): As recently as 10 years ago, about 100,000 lions roamed the African continent. Yet studies have indicated their numbers have dwindled by 70 percent or more. This program sheds light on the predators' plight, including a virus spread via jackals and hyenas and the lions' quest for food that often leads them from the safety of wildlife preserves into the sights of hunters' rifles. The program also examines efforts to maintain the lion population, including a South African experiment with artificial insemination, and a program that electronically tracks the lions' habits, helping livestock owners shield their herds more effectively. Peter Coyote narrates.
"Mystery! Jericho" (9 p.m., PBS): A new four-episode suspense series ushers in the 26th season of PBS' "Mystery!" franchise. Robert Lindsay plays Scotland Yard detective Michael Jericho, a crime solver whose own back story is as intriguing as many of his cases: As a child, he witnessed the murder of his father, a police officer. His dedication to his work -- born of the disappointment he experienced when his childhood sweetheart chose another man -- has made Jericho a media darling. In the first two-part series, "A Pair of Ragged Claws," airing Sunday and May 7, Jericho investigates a murder and a kidnapping that appear connected by the kidnap victim's secret double life.
"Jesse Stone: Death in Paradise" (9 p.m., CBS): Tom Selleck reprises his role as a New England police chief in the third movie based on Robert B. Parker's Jesse Stone novels. This time, Stone investigates the death of a teen-age girl whose parents never reported her disappearance. Viola Davis and William Devane also star.
"Life in the Undergrowth" (8 p.m., Animal Planet): It's bugs galore when David Attenborough takes viewers on a journey deep into the insect realm on "Life in the Undergrowth." This five-part series employs innovations in lighting, optics and computerized motion control to reveal the insect world from the never-before-seen perspective of its extraordinary inhabitants. The first episode charts "Invasion of the Land," when, just over 400 million years ago, tiny creatures left the seas. Since then, invertebrates have become the most successful group of animals, adapting to every environment on Earth. As such, the film is a reminder for its human audience to stick together against our common oppressor: For every one of us, 200 million insects are poised to bug us!
"Family Guy" (9 p.m., Fox): The animated series "Family Guy," never one to run from controversy, takes on the gay-marriage debate in tonight's episode. When Mayor West decides to ban the practice in town, Brian becomes a crazed activist.
"Grey's Anatomy" (10 p.m., ABC): As "Grey's Anatomy" gets closer to wrapping up a stellar second season, Burke is feeling the pressure as he is forced to operate on a musician whom he idolizes. Meanwhile, Addison takes Alex to task for his behavior in a sensitive case.