Arctic Terns

August 13 - We had great fun watched arctic terns, Sterna paradisaea, fishing.

They pluck fish from the surface of the water but can also dive up to 20-inches deep to make their catch. While fish make up most of their diet, they also eat crustaceans, insects, and less often molluscs, worms, and berries. During the time we were watching, we only saw them eating fish.

From our vantage point it was hard to see how large they are. They are 13 - 14 inches from tip of their bill to the end of their tail and have a wing span of 30 - 33 inches but only weigh 3 - 4 ounces. Arctic terns mate for life and nest every one to three years. Together the couple will select a nesting site, defend it against predators, and incubate their eggs. The chicks develop quickly and can begin their first migration within a few months of hatching but won’t reach maturity until they are three to four years old. The annual migration takes a meandering route to take advantage of wind currents. The route is from the Arctic along the coast, of any continent, to the Antarctic and back, an average round trip distance of 30,000 to 40,000 miles or more. When you consider that these birds can live 15 to 30 years they can travel over one million miles or more in their lifetime. Very impressive for something that weighs so little.

Of course I didn’t know much about arctic terns before our trip so I looked up information on All About Birds and American Oceans. Check their sites for more information.

***