A Gilroy woman who stepped into her backyard Sunday morning to chide her small dog for barking during the night was surprised to hear a deep growl - and it wasn't coming from her poodle-mix.

Crouching on top of the backyard fence and staring down at her was a mountain lion cub that had apparently been sharing the backyard, and bowls of dog food, with her 2-year-old dog, Lucy.

"I came out and said, 'Lucy, why were you barking so much?' " and then I heard, 'Grrrrrrrrrrrr,' " Maria Lopez recounted in Spanish. "I turned around and looked up and - Ay mamacita! I was so scared. I thought, 'What is it?' It looked like a baby lion. But I thought, 'No, it can't be.' "

Within minutes, Gilroy police, an animal control officer and state Department of Fish and Game wardens were at her home on the 8800 block of Carnation Lane to tranquilize and remove the 30-pound lion, which was released hours later in a state wildlife area in Santa Clara County.

"We were just surprised," said Lopez's son, Ivan, 16. "We didn't expect a lion in our backyard, especially because there's a lot of other houses around."

No one knows when or how the lion got to Lopez's backyard, which is in an urban residential area not far from the hills. Lopez said that for the past week Lucy had been barking during the night, and generous portions of her food had been disappearing.

"She wasn't getting fatter. I thought there must be a rat or something," Lopez said.

At 11 p.m. Saturday, Lucy was barking again and Lopez walked out to check on her but didn't see anything unusual - except that her bowl was empty.

"I thought that maybe my son forgot to feed her, so I gave her some food," Lopez said.

The barking started again at 3 a.m.

"I thought my neighbors were going to be upset about it," she said.

Sunday morning, after seeing the lion, she ran to her neighbor, who took one look at the spotted feline and called police.

Gilroy police Sgt. Wes Stanford said the unusual call came just before 9 a.m. Sunday. Stanford said the cub was lying on the fence when officers arrived.

An animal control officer used a tranquilizer gun to shoot a dart into the cat from a window. The cat jumped down into the backyard and fell asleep.

Stanford said Carnation Lane is on the western side of the city in an urban residential area that is close to the hills.

He said last year on Memorial Day, he shot and killed a 70-pound mountain lion that was in a tree - a killing that was captured on video and prompted much criticism of the department.

"I felt terrible shooting it," Stanford said. But he said tranquilizing the big cat was a dangerous option because the drug might not work right away, the cat could run, and there were many people in a park nearby.

"We were all very happy today with this outcome," he said.

Maria Lopez said her family once caught a parakeet that had visited the backyard and now owns it as a pet.

"But a lion - no," she said. "It was beautiful. It was quite big. It's a good thing nothing bad happened. There are lots of young children in this neighborhood."

From now on, she said, Lucy - and her food - will spend nights indoors.

"She had her doghouse and bedding, but it's getting cold," she said.