12/09/2012 02:17 pm ET

Animal Photos Of The Week: Polar Bears, Hummingbirds, Tiger Cub With Puppies And More Pictures

This week saw a number of great animal stories to bring you holiday cheer. The National Zoo in Washington, D.C. announced that Billie Jean, an Andean bear, is pregnant with twins! If she carries her cubs to term, they will be the only surviving Andean cubs in a North American zoo since the birth of Billie Jean’s first cubs. This news is especially poignant since her mate, Nikki, was euthanized in August after a long struggle with cancer.

The scientific community has chosen to honor President Obama by naming a new species of fish after him. Etheostoma obama, a newly discovered freshwater darter, lives in Tennessee rivers and creeks. "We chose President Obama for his environmental leadership, particularly in the areas of clean energy and environmental protection, and because he is one of our first leaders to approach conservation and environmental protection from a more global vision," the researchers said.

Farther up north from the new fish species, wild horses are at the center of a land dispute in Kentucky. Sequoia Energy is trying to rid the horses from a former mining site, while the Humane Society of Kentucky argues that landowners have given permission for the animals to remain. "Just leave the horses alone, that's all we want out of it," Humane Society president Marcella Chadwick said Tuesday.

Meanwhile, stray dogs are finding sanctuary across the world in Sarajevo, where a law stops them from being killed. Although other regions in Bosnia have ignored the edict, the law is respected in the capital city, thanks to a government-supported dog shelter that performs sterilizations.

As the year wraps up, Vetstreet has announced their list of Most Popular Puppy Names Of 2012. Click here to find out if your pooch made the top 10.

If you have a cute pet, make sure to submit a photo to our Cutest Pets of 2012 slideshow.

Find some of the week's best animal photos below:

Animal photos of the week 12/2--12/8
Animal photos of the week 12/2--12/8