Watch the full episode of PBS Nature's Silence of the Bees, which looks at a recent phenomenon dubbed Colony Collapse Disorder (CCD).

This week's dirt: Scientists say dinosaur flatulence helped warm Earth, Orangutans get into iPads, DNA traces gray whale population decline back to whaling era, Cypress family of trees tells us quite a bit about evolution, Brazilian rainforest fungus takes over ant brains, and more.

An interview about koala communication, vocalization, and social structure with Dr. Bill Ellis, head of The University of Queensland's Koala Ecology Group.

Information about the eucalyptus leaf-eating marsupial Phascolarctos cinereus.

A fight erupts between two koalas after one of the males invades the other's territory.

A male koala roams the Australian suburbs in search of a mate to produce offspring.

A baby koala consumes his mother's pap, a secretion that will give the joey the bacteria needed to digest eucalyptus leaves.

Watch the full episode of the PBS Nature film, The White Lions— the story of two remarkable and extremely rare white lion cubs on their journey to adulthood.

Cracking the Koala Code explores the day-to-day dramas of an extended family of koalas, seen through the eyes of the scientists studying their every move and vocalization. Watch a preview of the film.

Kruger National Park is one of the largest game reserves in Africa, located in north-east South Africa, and spanning 7,523 square miles (19,485 square kilometers).