LOS ANGELES (AP) -- It may sound like a West Side Story-style love story, but some dogs love big cats.
Cheetahs are the fastest mammals in the world, but they also are the world's biggest scaredy-cats -- so much so that they don't breed easily and are in danger of going extinct.
Some zoos are introducing dogs to calm the skittish cats and bring attention to their plight. They're pairing "companion dogs" with some cheetahs to serve as playmates and to provide the cats with guidance.
"It's a love story of one species helping another species survive," said Jack Grisham, vice president of animal collections at the St. Louis Zoo and species survival plan coordinator for cheetahs in North America.
Or, to quote Stephen Stills, it's a matter of loving the one you're with, he said.
"It is all about comforting and reassuring the cheetah," said Janet Rose-Hinostroza, animal training supervisor at the San Diego Zoo Safari Park -- the top U.S. breeder of cheetahs in captivity. In the past 40 years, 135 cheetahs have been born at the park's breeding facility.
The cheetahs most often found at zoos and wildlife parks are not considered good breeding candidates, they don't relate well to other cheetahs, or they are abandoned by their mothers, Rose-Hinostroza said. But they seem to take easily to companion dogs and look to the dogs for play and example.
Of the 19 cheetahs at Safari Park, four have dogs. Four of the zoo's cheetahs also have dogs.
The dogs, usually from animal shelters, and cheetah pups generally are introduced when they are about 3 months old.
"In this relationship, the dog is dominant, but we look for dogs that want to be a buddy," Rose-Hinostroza said. "The dog always has the cat's back, but it's never the other way around. Dogs worry about their cats. They protect their cats."
One of the most popular draws at Safari Park is the 100-meter cheetah run where the public gets to see firsthand the speed of "nature's perfect sprinter."
"Speed is incredibly important. It is their survival technique, in a nutshell," Rose-Hinostroza said. "If they can't run, they won't survive. They are not equipped to be confrontational."
A cheetah's claws don't retract, so they have footing that takes them from "zero to 60 in 3.4 seconds," she said.
"That's faster than every single car on the market, and it only takes three steps," Rose-Hinostroza said.
Cheetahs use their tails like a rotor to balance while they are running. Their top speed is 60 to 70 mph, based on size, but they can run that fast only for 20 or 30 seconds. Extending that to a minute or more puts the animal in serious jeopardy of death.
"Overexertion, heat exhaustion can literally cook their organs at that speed," Rose-Hinostroza said. She added the average cheetah chase in the wild is 200 to 300 meters.
Safari Park's cheetahs chase a lure for 100 meters, a sprint that seldom exceeds 6 seconds.
A century ago there were 100,000 cheetahs in the wild, Grisham said. Today there are fewer than 12,000. The species has become extinct in at least 13 countries. There are about 280 captive cheetahs in zoos across the United States.
As captive efforts to save the species continue, Grisham worries there is no wild to send them home to because habitat is being swallowed up by developers and poachers are killing the cats for their fur.
Cheetahs live 12 to 15 years in captivity. Males weigh 120 to 150 pounds, and females 100 to 120 pounds.
The dogs come in all sizes. At Safari Park, the smallest and sweetest is Hopper, a male mutt who weighs 40 pounds. He's teamed with Amara, the toughest female cheetah on the team, Rose-Hinostroza said.
Cheetah females don't go into heat like other cats. Instead, they have to be brought into estrus by a male cheetah, the experts explained. That's why breeding is so hard -- because they aren't social animals, they live independently, and they seldom hang out with one another.
Although the dogs and cats live together, they are not always with one another. Dogs have play dates with other dogs and humans. Mealtimes always are spent apart. The dogs eat kibble, and the cheetahs eat steak.
"The dogs are the bosses in these relationships," Rose-Hinostroza said. "If they ate together there would be one really fat dog and a really skinny cheetah."
One of Safari Park's dogs -- the only non-shelter dog -- is Yeti, an Anatolian shepherd. She works with two cheetahs -- Johari and her brother Shiley.