Baby river otter is the Oregon Zoo's newest addition - wave3.com-Louisville News, Weather & Sports

Baby river otter is the Oregon Zoo's newest addition

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Baby river otter, born Nov. 8, 2013. Photo: Oregon Zoo Baby river otter, born Nov. 8, 2013. Photo: Oregon Zoo
PORTLAND, OR (KPTV) -

A baby river otter is the newest addition at the Oregon Zoo.

Tilly, a North American river otter, gave birth to her second pup of the year on Nov. 8. The newborn weighed just shy of five ounces but has nearly tripled that weight in 11 days.

Zoo keepers credit Tilly's naturally high-fat milk for the weight gain.

"We're pretty sure this pup's a male," said Julie Christie, the zoo's senior North America keeper. "But Tilly is very protective, so we can't be positive until our vets conduct a more thorough exam."

Tilly and her pup are currently in a private maternity den. It will be at least another month or two before visitors will see them in the Cascade Stream and Pond Habitat.

Young river otters usually open their eyes after three to six weeks. They then begin walking at about five weeks.

Swimming, however, does not come naturally. Pups must be taught to swim by their moms.

"Young river otters are very dependent on their moms, and Tilly has been very nurturing," said Julie Christie, the zoo's senior North America keeper.

Her first pup, Mo, was born on Jan. 28. That otter was named after the Molalla River.

Keepers have yet to decide on a name for the new pup, but zoo workers said it will likely be named after a local river or waterway, as well.

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