Luke Dollar is on a mission for the National Geographic Society. He is out to save the world's big cats -- the lions, tigers and leopards that you would think are perfectly able to take care of themselves.
They're not, said Dollar, who is a biologist by training. There are twice as many tigers in captivity, he said, as there are in the wild.
"We'd like to think of these animals as magnificent predators, but there's a super-predator, and that's us," he said.
Dollar is part of a project at National Geographic called the Big Cats Initiative -- an effort on television, in the society's magazines and online to spread the word that the animals need help. ABC News is a frequent content partner with National Geographic.
Fifty years ago, says National Geographic, there were 450,000 lions in the bush; their numbers have since dropped to 20,000.
So the society is trying to raise money so that local farmers in poor countries can get help tending the land in ways that do not threaten the species around them.
The society asks people to make donations online or by texting. If trick-or-treaters come to your door on Halloween dressed as lions or tigers, look to see how their coin boxes are decorated; they may be collecting for the Big Cats Initiative.
"I have a two-year-old," said Dollar, "who just loves those animals. I can't imagine having to explain to him that we knew there was a problem, and we knew what to do."
This is not to accuse human beings of mindless evil.
Certainly, there is plenty of hunting that goes on, but the bigger problems are destruction of the animals' habitat, and rampant poaching that happens in Asia and Africa, where there is often poverty beyond Westerners' ability to imagine.
In the mountains of Central Asia, snow leopards are being killed because they prey on livestock owned by local herders, and because some of their body parts are used as ingredients in traditional Eastern medicine.
In Indonesia and surrounding countries, two percent of the clouded leopard's habitat is lost every year, according to National Geographic, because trees are cut down for palm oil.
"The cats are keystone species," said Dollar, "like the keystone of a bridge. As predators, they help maintain the balance of nature.
"They're also indicator species. If they're disapearing, something more serious is going on as well. We're also putting ourselves in danger."
It would not take that much money to protect the animals.
Conservation biologists have latched on to the idea of "hotspots," specific places where many species thrive together.
Protecting those few hotspots, scientists say, is much more efficient than trying to get overburdened local governments to try to cordon off large swaths of the wild.
"We have these iconic, majestic animals," said Russell Howard of National Geographic, "and we don't want to talk about them to our children the way we do about dinosaurs."
(For more information, and to see what you can do, go to the site set up by National Geographic: "Cause an Uproar.")