When a nearby bull elephant took notice, he quickly moved in to protect them, charging our vehicle in the process.

CNN: The Gathering: Sri Lanka's great elephant migration

The call of a bull elephant is unmistakable in the African plains.

CNN: Drought endangers wildlife in African park

We jumped from the imminent attack of one fur seal, into the flappers of another, passing en route the odd bull elephant seal weighing in at about four tons.

CNN: STORY HIGHLIGHTS

We were eating lunch in the central tent, washing down slices of tasty wood-fired pizza with glasses of gin and tonic, when a massive, six-ton bull elephant decided to crash our party.

BBC: Zimbabwe, a side you've never seen

As we approach them in the vehicle, an elephant bull charges a lion as a few other lions look on.

WSJ: Walk With the Animals

The elephant bull continues to chase the lion, holding him at bay and allowing the younger, slower elephants to put some distance between themselves and the super-predators.

WSJ: Walk With the Animals

On a recent visit to the National Zoo in Washington, I met with Preston Foerder and Diana Reiss of Hunter College, who showed me what Kandula, a young elephant bull, can do if the problem is presented differently.

WSJ: The Brains of the Animal Kingdom