Ellen Gray's weekend TV picks: Finale of 'Show Me a Hero,' Discovery's 'Shweekend' and more

* EXPLORER: WARLORDS OF IVORY. 8 p.m. Sunday, National Geographic Channel.

NatGeo marks World Elephant Day with a report on the illegal trade in ivory. Using an artificial elephant tusk embedded with GPS, National Geographic's

Bryan Christy, whose story is the magazine's September cover, tracks the trade through a web of poachers, African militias and terrorist groups.

* SHOW ME A HERO. 8 p.m.

Sunday, HBO.

The final two episodes of this fact-based miniseries from "The Wire" creator David Simon left me gutted, thanks to award-worthy performances by Oscar Isaac ("Inside Llewyn Davis"), as former Yonkers mayor Nick Wasicsko, and Catherine Keener ("Capote"), as Mary Dorman, who turns out to be one of the story's least likely heroes.

* SHWEEKEND. 9 p.m. Saturday and 8 p.m. Sunday, Discovery.

We've survived Discovery's Shark Week and Syfy's third "Sharknado" this summer, but Discovery's hoping there's a little more to chew on before Labor Day, with two nights of shark-related programming that it's calling, yes, "Shweekend."

* GIRLFRIENDS' GETAWAY 2.

8 p. m. Saturday, TV One.

If you watched the first movie - and a sequel suggests plenty of people did - then why miss the reunion of Garcelle Beauvais ("White House Down"), Malinda Williams ("Soul Food"), Terri J. Vaughn and Essence Atkins ("Half & Half")? This latest getaway focuses on the runup to the wedding of Beauvais' character to a high-school teacher, played by "Being Mary Jane" star Stephen Bishop (pictured above with Beauvais).