Brown-polar hybrid bears may be a result of climate change, herd formations help caribou avoid mosquitos, data system connects animals from different zoos for captive breeding, and fluoride keeps sharks cavity-free.

This week's dirt: new study suggests a warmer, greener Antarctica 20 million years ago, gorilla populations start to rebound after 2004 ebola outbreak, sponge DNA may give us new insight into our central nervous system, new research shows that goat moms know their kids' voices, and more.

This week's dirt: New species for 2012 includes sneezing monkey, zebrafish "smell fear", harvestman spider managed to cross the Pacific Ocean 82 million years ago, tomatoes contain more genes than humans, and more.

Among the mountain gorillas of Rwanda, Titus reigns as king. Watch the full episode online.

NATURE producer Jill Clarke gives an update on the leadership shakeup in Titus's gorilla family.

While his prolific mating is a clear sign of the king's success, this unique gorilla's extensive family tree grew out of tragic circumstances.

NATURE retraces the life of Titus, silverback leader, from birth to present reign, spanning a tumultuous period in the history of a species and a nation in "The Gorilla King."

Check out these baby animal wallpapers to use on your computer or mobile phone.

In 1967, local villagers in Africa's Equitorial Guinea captured a remarkable baby gorilla with a coat of pure white. Watch the full episode online.

Recent challenges to Titus's rule by his rival, Kuryama, have the entire group of gorillas on edge.