WASHINGTON -- The Panda Cam has delivered up the closest look yet of giant panda Mei Xiang with her new teeny tiny cub.

The baby was about the size of a stick of butter when he or she -- we'll know which, hopefully, in a few weeks, when vets are able to do an official exam -- was born on Sunday night.

Zoo spokesperson Jennifer Zoon tells HuffPost DC that until that exam, "we won’t know exactly how much it’s grown."

"However, keepers have seen and heard it nursing," Zoon said. "So we know that it is in fact growing, we just can’t tell by how much quite yet. It’s fair to say that it is still similar in size to a butter stick until we know more."

Be sure to spend all of your waking hours watching this new family on the National Zoo's Panda Cams -- the only way to see them just yet. Here's a link to one of the Panda Cams and another. You can also watch from your phone, using the National Zoo's app.

And check out the Flickr pool of Panda Cam screen grabs showing the baby, too.

Also on HuffPost:

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  • Tai Shan takes a short plunge off the edge of a faux rock during his debut to the press November 29, 2005 at the National Zoo. Tai Shan was sent to China in February, 2010.

  • Mei Xiang and Tai Shan, who was born at 3:41 a.m. July 9, 2005, weighing only a few ounces at birth. This photo was taken in December, 2005.

  • Giant Panda cub Tai Shan cuddles with his mother, Mei Xiang, while they eat melon balls in the morning at the National Zoo's Giant Panda Habitat on August 30, 2006.

  • Giant Panda Tian Tian plays with a box on January 20, 2011 at the National Zoo. The snack is made with apples and pears frozen in apple juice.

  • Giant Panda Mei Xiang eats a breakfast of bamboo at the National Zoo's Giant Panda Habitat on August 30, 2006.

  • Giant Panda Tian Tian enjoys a fruitcicle at the National Zoo on January 20, 2011.

  • The 4th Birthday Of Giant Panda

    Giant panda Tian Tian eats bamboo at the National Zoo on July 9, 2009.

  • Tai Shan officially celebrated his fourth birthday with singing, guests and a massive, three-tiered "veggie-sicle" cake. The frozen masterpiece was made over the course of two weeks by Zoo commissary staff by freezing a combination of water, beets and beet juice while enhancing it with bamboo and fruit. Tai quickly took to the frozen treat, licking at the ice, spotting his furry face with the melting beet juice.

  • Panda cub Tai Shan is examined, weighed and measured on September 19, 2005.

  • The National Zoo's Chief Veterinarian Dr. Suzan Murray, Curator of Primates and Giant Pandas Lisa Stevens and animal keeper Nicole Meese conducted a health exam on Tai Shan when he was a cub in 2005.