Birds of the Seas
Seabirds’ lives play out over ocean waves. They are true marine organisms, feeding at sea and only coming to land to breed. Ornithologist John Chardine will tell us more about them.
Seabirds are our constant companions on our cruise aboard the expedition ship, some following us all day. They are never lost, even thousands of miles from land. They are right where they want and need to be: Where the food is. Living their lives at sea isn’t easy. Only about 300 of the world’s 10,000 species of birds know how to survive among the ocean waves.
There are four main groups of seabirds. The first are penguins. The second are 'tube-nosed' petrels and their cousins, such as the iconic albatrosses. Third are the cormorants, pelicans, and gannets. Fourth, we have gulls, terns, auks, and skuas. With the exception of penguins, who live exclusively in the southern hemisphere, the three other seabird groups can be found on the coastlines and adjacent oceans of all seven continents.
Finding food among the waves
Food is spread out over vast distances on the open ocean, found in patches of concentrated areas of high ocean productivity where algae grows profusely. To find enough food to sustain themselves, many seabirds use the wind to cover vast distances and effortlessly glide over the waves. Some seabirds even find their meals by smelling the chemical that algae produce.
Seabirds are at the top of marine food chains and eat crustacea like krill, small fish like herring, and squid. Species such as penguins and auks are prodigious divers and plunge hundreds of feet under water. They can stay underwater for several minutes to catch their prey.
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Photo: Dr. John W. Chardine
Nothing to Drink at Sea
Living things need freshwater, which is a big problem when you live at sea. Seabirds have evolved a special gland, the salt gland, which strips salt from their blood. The gland is located at the top of the head, just under the skin, and exudes a highly saline solution that drips from the seabird’s bill (or from the nose, in the case of the seabirds with tube noses). Given the chance, penguins prefer eating snow at the colony to obtain freshwater. We have even seen young penguin chicks catching snowflakes as they fall from the sky—a magical and humorous sight to behold!
The Circle of Life
Seabirds can’t build their nests on the ocean, so they come to land to breed. Most breed together in tightly packed colonies on the ground or on cliffs. Colonies tend to be on islands or isolated stretches of coastline, free from mammal predators. Some colonies are a long way from concentrations of food, but that’s not a problem for most seabirds, because they fly so efficiently.
Typically, seabirds only lay one egg per year. This is because the parents only bring back enough food from sea to feed a single chick. Some species can rear more chicks because their colonies are closer to where they feed.
Many seabirds return every year to exactly the same place in the colony and pair with their mate from previous years. Returning to the same spot is a way they find each other. Seabirds have long lives (albatross can live to be over 60!) and sometimes stay with the same mate for many years, until one of them dies. Irreconcilable bird differences sometimes occur as well, leading to a ‘divorce’ and the birds searching for new mates.
Helping our seabirds survive
Sustaining seabird populations is a big concern. One problem is floating plastic, such as discarded straws and lighters, which seabirds may mistake for food and bring back to their chicks to feed. If this happens, the plastic takes up space in the chick’s stomach and the bird eventually dies.
We at Hurtigruten are very sensitive to this problem and have eliminated single-use plastics from our ships.
Introduced rats wreak also havoc in seabird colonies by eating bird eggs and chicks. Rat removal programs have allowed colonies to recover. Oil pollution, overfishing, climate change, and coastal development are other serious problems facing seabirds. The goal of conservation is to promote healthy populations and not let any species go extinct, as happened to the Great Auk in the 1800s.
Our expedition cruises are the best way to see a range of seabirds and learn more about each of them from the expert Expedition Team on board the ship. They’ll point out different species to you out on deck. By the end of your cruise, you’ll likely be able to identify them yourself. Understanding the incredible ingenuity and skill it takes for these birds to survive and thrive will only add to your admiration for them.
