Bellowing koalas, therapy dogs and hibernating alligators this week in Animal Tales

Therapy dogs  at San Francisco International Airport

Anxious passengers at San Francisco International Airport can now turn to therapy dogs to help quell their fears. 

 CBS station KPIX5 in San Francisco reports that nine therapy dogs known as The Wag Brigade, a new branch of the San Francisco SPCA’s Animal Assisted Therapy Program, will be hanging out – with their volunteer owners – at SFO’s check-in areas, terminals and gates throughout the holiday season. 

Studies show that petting a dog, even for a few minutes, can lower a person's heart rate, relieve anxiety and reduce stress.

Koala bellow finally explained

 Koalas are able to bellow at a pitch about 20 times than they should be able to according to their body size.

Male koala bellows are so deep that the sound designers of Jurassic Park used them to create the T. Rex roars.  

How exactly they do it has long puzzled scientists – until a study came out this week, explaining that koalas have an extra set of vocal cords, unique to this species. 

They're the first known land mammal to produce vocalizations through an organ other than the larynx. Published in the journal Current Biology, the study says that this is the first time such vocal cords have been discovered, but the researchers expect that they will turn up in other animals with low voices.

Alligators prepped for hibernation 

Yangtze alligators like to burrow deep in holes to hibernate through the winter. But for the more than 10,000 of those gators that live in the cement-pools of a nature reserve in East China’s Anhui Province, digging holes is not an option. So this week, officials there brought 8,000 of them indoors for the winter. As for the other 2,000, they’re still trying to find space for them. The gators are listed as first-class protected animals under Chinese law and are classified as critically endangered by the International Union for the Conservation of Nature (IUCN).

The world’s largest oyster?

 A team from the Wadden Sea Centre in Denmark found a massive oyster in October. Measuring in at nearly 13 inches, it could be a record breaker. 

Scientists estimate that it is about 20 years old, based on its size. 

The oyster is still living, and the Wadden Sea Center hopes to keep it that way for years to come. As it waits on the verdict from the Guinness Book of World Record’s the organization is making plans to keep the oyster in an aquarium at the sea center.

A generous monkey becomes a YouTube star

A Capuchin monkey named Chino has developed quite a following on YouTube after he was videotaped teaching a person how to crush leaves with his hand. The video was posted in June 2013, but it caught lots of attention this week.

Chino has been living at the International Primate Rescue sanctuary in South Africa for three years. It's no surprise that he's a smart little fellow -- monkeys, especially chimpanzees and orangutans, are among the smartest species. Studies have shown that chimps are actually better able to remember numbers than adult humans.