NIGHT STALKERS too cowardly to show themselves by day are threatening the very survival of the African elephant. We caution that what our Cover Story shows this morning may be difficult to watch. It comes to us from M. Sanjayan, a CBS News contributor who has since joined the group Conservation International.
As a cloudless day yields to a moonlit night in this savannah in Northern Kenya, a dozen wildlife rangers armed with automatic weapons begin their nightly patrol.
Tonight, the team is on edge, says Commander John Palmieri.
"They give us a big, big worry," he said, as there is more poaching on the full moon.
And it is a deadly business. Six Kenyan rangers and three times as many poachers have been killed in gun battles the last two years.
Each night, rangers go up to an observation point at higher ground, then sit all night long and scour these valleys, looking for any sign of movement, or a gunshot.
Night vision goggles help spot elephants -- and see potential human threats.
For this night at least, it was all quiet for Nature's so-called "great masterpiece."
The African elephant is the largest mammal to walk the Earth; a majestic creature that shares many noble characteristics with humans -- strong family units and maternal bonds, intelligence, longevity and, yes, terrific memories.
Also, like us, they seem to grieve, and appear to mourn their dead, a trait which, tragically, has been on display far too often of late.
Some 25,000 elephants a year are now being lost to poachers in Africa.
"It's the worst that it's been in the last 30 years," said Ian Craig. "It's a steady deterioration, and it's getting worse."
The Kenyan-born Craig leads conservation efforts for the Northern Rangelands Trust, an innovative partnership of nearly 20 wildlife conservancies.
In years past, said Craig, the typical poacher was a solitary local simply trying to feed his family. Today, though, foreign criminal syndicates with sophisticated equipment kill viciously and in ever greater numbers.
In an infamous 2012 episode, an estimated 300 elephants were gunned down in Cameroon right inside a national park.
So who's behind it?
"I think clearly China is driving this, or it's coming from the Far East," said Craig. "Ninety percent of the ivory being picked up in Nairobi Airport, or Kenya's port of entry and exit, is with Chinese nationals."
Despite laws banning the harvest and sale of ivory, it remains a powerful status symbol in China and the Far East, where it is used commonly to make artworks and religious icons.