USA: Seattle #11 Aquarium (Part b)

April 1, 2016 by JT & DY

After exploring the exhibits in the indoor area of Seattle aquarium, it was time to venture outdoors to visit the harbour seals and the cute sea otters.

The harbour seals are one of the main attractions around the harbours of towns and villages along this coast. They are seen by researchers as barometers of the health of Seattle’s waterways because of their diet… sole, flounder, sculpin, cod, herring, octopus and squid. These are all links in a food chain that is becoming increasingly vulnerable to pollution, development and other human activities.

When in the water they are streamlined, but out of the water they flip flop along in a rather ungainly fashion. While their hind flippers are used to propel them through the water, these aren’t used on land. When they “haul out” on sandbars, beaches or onto rocks, they have to use their front flippers and an undulating movement to get along, giving them a common nick name of “crawling seals”.

Harbour seals have a thick layer of blubber which not only provides them with insulation in these cold waters of Puget Sound, but also adds buoyancy for swimming.

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Harbour seals can remain underwater for close to 30 minutes while hunting for food. Fortunately we didn’t have to wait that long between dives as their keeper gave them fish to eat. But it was impossible to guess when they would come up to the surface. Most of the time, their nostrils remain closed. Once they resurface, they must consciously open their nostrils to resume breathing.

Some cute sea otters live in the next pool. We asked how these otters came to be in the aquarium when there are plenty of surrounding waterways. The answers were interesting.

One was discovered on an airport runway in Alaska suffering from hypothermia. One was just a few weeks old when her mother was accidentally killed by a boat in Kodiak, Alaska. She was cared for ’round the clock’ by staff and volunteers for several months before joining our other otters. She is now the mother to three pups, all born at the Seattle Aquarium. One of those now has a pup of her own. And another one was rescued after being caught in a fishing net as a young pup. They all seemed very content.

Sea otters have very thick fur to keep them warm. We were told that there are abou 500,000 hairs on every square inch of a sea otter’s fur. That apparently, equals the number of hairs on 3 or 4 normal human heads… normal meaning not including those heads that are thinning or bald! Sea otters don’t go bald. They die of cold if they did.

These two were having a rest after a stint of grooming; rolling and twirling in the water; rubbing and raking their fur with their forepaws and licking the fur with their coarse tongues. They need to keep their thick fur very clean because it insulates their bodies by trapping tiny air bubbles and keeping a layer of air between the water and their skin. Dirty fur loses its insulating qualities allowing cold water to penetrate through to the skin.

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Reluctantly leaving the seals and the otters, we wandered through the connecting dome section of the aquarium to see some of the shore birds of this area. One was the Long-billed Curlew, the largest shorebird in North America. It uses that long, curved bill to probe for prey such as shrimp and crabs in mudflats.

Although the adult birds have long bills, their newborn chicks don’t. They are therefore unable to probe for food in the mud. So their parents take them to grasslands where they can find insects to eat. After two or three weeks, the female usually leaves the care of the brood to the male. She’s done her stint sitting on the eggs in the brooding process.

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Another local shore bird is the Black Oystercatcher… although that is a misleading name. Its favourite food is mussels rather than oysters! It searches at low tide in the places where mussels and limpets adhere to the rocks. It uses its strong bill to pop limpets and chitons off the rocks and separate the fleshy foot from the shell.

One of the beauties of seeing birds up close is to check out the way feathers are distributed over the bird. This bird, a Killdeer, Charadrius vociferus, had just finished grooming.

These birds are sometimes called ‘chattering plovers’. Their scientific species name, vociferous, is Latin for noisy and they are… in fact, we were told that Killdeer chicks start making noise even before they have hatched. That doesn’t help in keeping the chicks safe from predators as they hatch in their simple nest, a scrape on sandy gravel ground. But the adult birds have a way of helping to keep the chicks safe. They often fake a broken wing, twisting one wing up onto their backs. Then they make themselves look vulnerable by dragging themselves away from the nest. It works sometimes!

Unlike many other shorebirds, Killdeers have short necks. But they have long beaks for digging in wet or muddy areas to forage. They feed primarily on invertebrates such as earthworms, snails, crayfish, grasshoppers, beetles and aquatic insect larvae.