Cougar Back in the Wilds After Visit to Irvine : Ecology: He’s groggy from the after-effects of a tranquilizer dart that dropped him out of a tree but otherwise OK. He is wearing a collar device to help researchers study his migration pattern.

M-3 was out for a quiet stroll, maybe for a bite to eat on a Friday night.

But the young mountain lion’s escapade into civilization was quickly halted by Lady, a startled dog who sent M-3--as he was dubbed last year by scientists tracking Southern California mountain lions--scurrying up a tree in the back yard of an Irvine house.

That is where police and city animal-control officials found M-3, cornered, confused and apparently not relishing his second brush with mankind.

“He’s afraid of people,” explained Jan Yost, a warden with the state Department of Fish and Game. “We like it that way.”

The 110-pound, 20-month-old mountain lion wandered out of his natural habitat early Friday evening and ended up in the back yard of Gary and Deborah Goldman’s two-story home, less than two blocks from the rolling hills east of Irvine.

The tracking device on the cougar’s collar told officials that he had been wandering the fringes of the city for the past two days. He was the first cougar to be caught in the city in recent memory, although there have been occasional sightings.

M-3 was released back to the wilderness area about four hours later, after a city animal-control officer shot him with a tranquilizer dart and carted the dazed animal away in a pickup truck.

“He was gorgeous, just gorgeous,” Deborah Goldman, 38, said Saturday about the fawn-colored feline. “Our biggest concern was that the cat wouldn’t get hurt.”

The Goldman family had just settled down to watch a television show at 8:30 p.m. Friday when they heard a loud rustle of leaves, a muffled thud and then the dog barking.

Gary and Deborah Goldman grabbed a flashlight and walked outside, thinking that the noise had come from an opossum climbing their vine-covered brick wall.

Gary Goldman walked under a brushy tree and looked up. To his surprise, he found himself in a face-to-face encounter with a snarling cougar.

“We backed out of there fast, and took the dog with us,” Deborah Goldman said.

During the next 45 minutes, at least four police officers arrived at the scene and held the cougar at bay until animal-control officer Duncan Gill arrived with a tranquilizer gun.

Gill coaxed the animal to turn to the side and then shot him in the left flank.

“He slid out of the tree to the ground,” Gill said. It was then that they noticed the collar.

M-3 is one of 11 mountain lions--eight female and three male--that have been fitted with tracking devices attached to a 2-inch-wide collar, Yost said. UC Berkeley scientists, in cooperation with county and state environmental agencies, have been monitoring the collared animals for the past two years to learn about their migration and territorial patterns.

In fact, M-3 had been tracked by one scientist earlier in the afternoon, wandering the rolling hills about a mile from the Goldmans’ house, Yost said.

“They knew where he was,” Yost said.

Scientists first collared him last year, while he was still living with his mother.

He has been left alone ever since, although scientists have been tracking him on an almost daily basis.

M-3 recently had set out on his own to establish his territory, Yost said, and was probably driven toward civilization by older mountain lions who already have established themselves throughout most of the remaining undeveloped land in the county.

After his capture Friday, Yost, Gill and Irvine police officers loaded up M-3 and drove him to a nature preserve owned by the Audubon Society, 15 miles from where he was found. M-3 was released about 1 a.m. Saturday, after the effects of the tranquilizer had largely worn off.

“He’s got a pretty good hangover by now,” Yost said Saturday.