Sept. 17, 2012: We've scoured the Web to find the best and most compelling animal stories, videos and photos. And it's all right here.

The National Zoo's Mei Xiang gave birth to a cub on Sunday.

National Zoo (Finally!) Welcomes a New Panda Cub

After five psuedopregnancies in a row, the National Zoo in Washington, D.C., is thrilled that giant panda Mei Xiang gave birth to a cub on Sunday night. “I’m cautiously optimistic as we haven’t seen the cub yet, but we know that Mei is a good mother," said Smithsonian National Zoo director Dennis Kelly in a press release. Mei Xiang was artificially inseminated in April, and the odds of her giving birth were only about 10 percent. This is her second cub. — Read it at NBC Washington

Orca Moms Live Longer to Care for Grown Kids

A new study could help explain why both human and killer whale moms live long past menopause. Orca females often make it well into their 90s, while males rarely live past 50. Scientists from the Universities of Exeter and York, the Center for Whale Research and the Pacific Biological Station studied 36 years of records for two populations of killer whales, finding that whales whose mothers lived longer tended to survive longer themselves — and this was particularly true for sons. Killer whale moms help their sons by assisting with foraging and providing support during fights, among other things. According to researcher Michael Cant, when it comes to humans, “both sons and daughters benefit from the presence of grandmothers, [but] in killer whales, only sons benefit.” — Read it at Discovery News

Efforts to Save Yellow-Legged Frogs Pay Off

They've been threatened by fungus, as well as decimated by wildfires, pesticides and loss of habitat — but restricting public access to some of the streams where mountain yellow-legged frogs live in southern California, and ridding those waters of predatory trout, seems to be helping to save the endangered amphibians. The frogs are now breeding in numbers that haven’t been seen in decades. "Amphibians in general, and frogs in particular, are resilient — if you give them a chance, they rebound," said Sam Sweet, professor of ecology and evolution at UC Santa Barbara. — Read it at the LA Times

Larry would rather nap than chase mice at 10 Downing Street.

New Cat Reports for Work at 10 Downing Street

Move over, Larry. The cat who was tasked with catching mice at London’s famed Downing Street address has been caught sleeping on the job one too many times. Just last week, British Prime Minister David Cameron reportedly found Larry asleep in his chair as a mouse scurried across his study — and the feline didn’t budge when his boss tried to rouse him into action. So Cameron has hired Chancellor George Osborne's tabby, Freya, to patrol the legendary building. The chief mouser post is being called a “job share” to avoid hurting Larry’s feelings. — Read it at the Daily Mail

Owner Gives Up Custody of Dog Abandoned on a Colorado Mountain

Last month, a group of eight hikers took turns carrying Missy, an injured German Shepherd–Rottweiler mix, down from Mount Bierstadt. Her owner, Anthony Ortolani, admitted to leaving her on the mountain a week earlier while hiking, claiming that he was unable to bring her back with him because he was suffering from injuries himself. As he now faces animal abuse charges, Ortolani has agreed to give up custody of Missy to one of the volunteers who rescued her as part of a plea deal. All of Missy’s rescuers are scheduled to appear today on The Ellen DeGeneres Show. — Watch it at Colorado’s 9News

Kim Kardashian Shows Off Her New Kitten

Have Mercy, that’s a cute kitty. Kardashian was photographed heading into the Dash boutique in Miami on Sunday with a fluffy, white kitten. She posted a "My new baby Mercy!" message on Twitter, along with a series of photos of the kitten, who seems to have been named after a song on boyfriend Kanye West’s new album. — See the photo at People Pets