PBS America (Freeview) Saturday

A look at animals' defensive strategies, including the act of self-sacrifice or risk of harm that typifies a mother's defence of her offspring

Retracing the English writer Agatha Christie's footsteps across England, exploring some of the real places that inspired her fictional works

Discover two of the greatest failed invasions in the history of naval warfare - the defeats of the Spanish Armada and the Allied fleet of the First World War

Investigations reveal the greatest scuttle and act of defiance in wartime history. Testimonies and CGI illuminate the events and subsequent salvage

Examining three historical collisions and discovering how they have shaped regulations and technological advancements

The team discovers two ships laden with deadly cargos - ticking time bombs set to explode, but no one knows when

During the First World War, two warships sank in controversial circumstances north of Scotland. Discover the mysterious stories behind these two wrecks

Retracing the English writer Agatha Christie's footsteps across England, exploring some of the real places that inspired her fictional works

Examining how the German Siegfried Line and the French Maginot Line protected their countries during World War II by using modern technologies

Pulitzer Prize-winning author Douglas A Blackmon, a member of the first integrated class in Mississippi, looks back at the school desegregation and how it transformed lives