Tilly the otter welcomed the two pups last month.
Den cameras at the Oregon Zoo are giving animal fans a behind-the-scenes glimpse into the progress of its newest additions: Two adorable otter pups.
Footage taken from the maternity den shows mom Tilly snuggling with her two tiny pups, who were born on February 26.
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The unnamed pups — one male and one female — each weighed just 4 ounces at birth, but they've already doubled in weight, thanks to their mother's naturally high-fat milk, according to Oregon Zoo. Tilly also gave birth to a third, smaller pup that did not survive.
The two surviving pups are expected to open their eyes after three to six weeks, and should begin walking at about five weeks old, the zoo said. They'll make their public debut in a month or two.
"Young river otters are extremely dependent on their moms, and Tilly has been very nurturing," Senior Keeper Julie Christie said in a statement released by the zoo.
Tilly successfully raised two healthy pups, Mo and Ziggy, after giving birth in 2013. She also took in an orphaned pup named Little Pudding, who was found at the side of a road in 2015.
"We expect she'll do well with her new babies as well," Christie said.
Among her roles, Tilly will have to teach the pups how to swim.
"This will be the first time Tilly has raised more than one pup at a time," said Curator Amy Cutting. "It's exciting that they'll be growing up together and have the opportunity to play and wrestle with each other."
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Tilly and the pups' dad, B.C., are key in helping to breed the otter population across North America. Tilly was just 4 months old when she was found wounded by an animal attack. She was nursed back to health before moving to the Oregon Zoo.
B.C., short for Buttercup, was also found orphaned in Arkansas in 2009. He was initially taken to the Little Rock Zoo, but transferred to Oregon the following year as a companion for Tilly.
Watch: Otter Parents Give Swimming Lesson to Their 5 Pups
