PALO ALTO (CBS SF) — A mountain lion and cub were spotted in a 100-foot-tall redwood tree in Palo Alto Thursday morning, but have not been seen since according to police.

Police said the call came at 6:20 a.m. from a resident in the 1700 block of Webster Street.

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Palo Alto police, animal control officers and regional park rangers are patrolling the streets and keeping an eye out for them.

Coincidentally, it was a man experienced with the big cats was the person who spotted them in his backyard.

“This particular resident has experience in the past with actually radio-collaring mountain lions, so we have very little doubt as to his credibility for what this animal actually is,” said Palo Alto Police Capt. Zach Perron.

The man’s wife, Marcella Bernstein, said the sound she heard in the redwood trees just before sunrise could not have been anything else but a mountain lion.

“I can tell you it’s a very percussive sounding, like drumming. Really guttural deep, deep sound. You can look it up on YouTube,” explained Bernstein with a laugh.

This is what an agitated mountain lion sounds like.

Bernstein is veterinarian. She said there were two big cats, likely a young female and her cub.

The female cat tried to walk out onto a small branch, when it started to give way.

“She came out to the edge of the branch, to see if she could jump, and decided it wasn’t a good idea and walked back toward the tree,” said Bernstein.

Police say the large cats come down from the hills into the city by walking through creek beds, but this case is unusual and more dangerous.

“It’s not just one animal we’re dealing with,” said Perron. “It’s two, and it may be one that’s more inclined to be protective of its young.”

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The area where the animals were spotted is a heavily residential area and also near schools including Walter Hays Elementary. Parents were advised to drive their kids to school as a precaution as authorities looked for the cats.

Some locals were left on edge.

“In this area, there are so many kids who bike and families that bike together. There’s such a mass number,” said area resident Jill Johnson.

However, others felt safe because of the increased patrols.

“I wasn’t at all concerned about a mountain lion attacking us given the police presence. That was very reassuring,” said Palo Alto resident Margaret Chai Maloney.

The California Department of Fish and Wildlife has also been notified to assist in the search.

Officers spent all day patrolling the neighborhoods, scanning the trees and used thermal imaging cameras to look for the pair of mountain lions, but came up empty.

Bernstein told KPIX 5 she will keep her dogs out of the backyard for at least another day.

“They could very well not find them. And they could be here until it’s dark and they can wander back in safety and comfort where they belong,” she said.

Palo Alto police says residents can follow their Twitter account at for updates on the situation.

Police advise anyone who sees a mountain lion to call 911.

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