Field Notes: a Northwest nature blog
One of the reasons many of us live in the Pacific Northwest is the natural wonders that amaze us all. On this blog Seattle Times writers and photographers will share their explorations of the natural world from snowcaps to whitecaps. Write us at firstname.lastname@example.org with your own sightings, questions and wonders to share.
Seattle Aquarium's Aniak the otter due any time
The Seattle Aquarium is expecting a baby otter any time from Aniak, above. Captive births are rare and special. The pregnant otter was photographed at the Seattle Aquarium on Dec. 20, 2011. (Courtney Blethen Riffkin/The Seattle Times)
Aniak couldn't be happier, munching on fresh, local seafood. But her keepers are pacing the floor. Aniak is due to give birth any minute now, and that has bird and mammal curator Traci Belting and C.J.Casson, director of life sciences at the Seattle Aquarium, standing watch.
She's doing great, and serenely going about her normal day, seems comfortable and right on track for an all-systems-go delivery, they report. The Seattle Aquarium was the first in the world to successfully breed northern sea otters, so Aniak, one of the aquarium's three resident northern sea otters, is in good hands. She's also done this before with success, another good sign.
But it's always dicey: Sea otters give birth in water, and the chances of a live birth are about 50-50. "They are an air breathing animal, born into water, there are just a lot of hurdles to have a successful pup raised. You can easily lose a pup and it's nobody's fault," Belting said. "We'll be monitoring it very closely."
So it's a nervous time.
But not for Aniak, who's been eating up a storm, gaining more than ten pounds from 62 to an expected 75 when she delivers.
Whenever that will be. It's always a bit hard to know with these things, because northern sea otters' implantation of the embryo is delayed, with the exact time between fertilization and implantation and the start of gestation hard to know.
Aniak was born at the aquarium from Lootas, a rescue from Alaska, so if her pup survives, three generations of the family will reside at the aquarium. Whether the pup stays there will depend on its gender -- if it's a male he will need to eventually be relocated, as males would compete with Adaa, the male already at the aquarium, and father of the pup.
But for now, it's just another day of eat, eat, eat: northern sea otters are the smallest marine mammals, and they maintain a 100 degree body temperature and humming metabolism by eating about 25 percent of their body weight a day in Dungeness crab, squid, white spot prawns, clams, the works. The northern sea otters at the aquarium get nothing but the best: local sea food from a vendor in Hood Canal, all restaurant quality.
It costs about $16,793 to a year to feed each otter, and a lactating female is a real budget buster. "We'll be asking the public for help," said Tim Kuniholm, spokesman for the aquarium. If the birth is successful, visitors will get to see the pup right away. There's no plan to close the exhibit or sequester the otters, who are used to activity and visitors.
The pregnancy was not an intended breeding, but a surprise.
The aquarium's goal was to limit breeding to make room for stranded sea otter pups, in partnership with the U.S. Fish and Wildlife Service and the Association of Zoos and Aquariums. To do that, Aniak's breeding was suspended, using birth control.
No one knew the longevity however of the birth control method being used with sea otters. So, aquarium scientists were keeping track of Aniak's hormone levels for the past four years. They were surprised to discover her pregnancy last June. Hormone levels had lead biologists to believe she was not capable of becoming pregnant.
"Aniak sure showed us," Casson said.
A baby sea otter pup looks a bit like a gray dandelion fluff, said Casson, because of their unusual natal pelage, a fur that is so fluffy it enables pups to float while the mother hunts.
"They are one big puff ball," Casson said.
A pup is about three and a half pounds at birth, and about the size of a fuzzy football. At about one month, a pup begins to swim and attempt to dive -- but it can't, Casson noted, because it is still so buoyant. Once it sheds that fluffy fur though, past the first month, "it's almost like your teenager getting a driver's license, that pup starts to dive and it will be everywhere, chasing mom."
Mothers do all their young's grooming at first, fluffing and blowing air into the fur and licking it, keeping the hairs locked together. Sea otters were mercilessly hunted for their incredible fur, which keeps their skin dry to the touch -- it's that dense, with at least half a million hairs per square inch. Water sucks heat 25 times faster than air, and all the air in between those hairs provides critical insulation.
The father of the pup, Adaa, is taking a little vacation at the Oregon Zoo, to make sure he doesn't bother either Aniak or the pup when it's born, Casson said. Aniak is about 8, and Adaa is 12. Aniak first gave birth in 2005, to a pup now in Pittsburgh.
The aquarium has featured northern sea otters in its exhibits ever since it opened in 1977, and the animals always have been very popular. "Next to the octopus, they are probably our number one," Casson said.
If the pup makes it, the public will be asked to help pick a name for the aquarium's newest arrival, all fluff and puff. And lungs: otter pups have piercing voices, very high and loud. "You'll be able to hear it all the way at Pike Place Market," Casson jokes.
Aniak did well the last time she gave birth, Belting said, and her mother Lootas was a skilled mother as well, Belting said, "So maybe that will add up to success."