Michael Ellis takes a look at a pair of seabirds that have set remarkable records for long-distance flying.
Years ago, on my first pelagic birding trip in the middle of foggy Monterey Bay, the on-board naturalist yelled “comic tern!” I asked the lady next to me, “Did he say ‘comic’? “Yep,” she replied. Even this premier birdwatcher could not distinguish at that foggy distance between the common and the arctic tern. They look a lot alike, especially from the deck of a rolling ship. So, we had to make do with the combo “comic” tern. Not something to add to your life list, but I think of it as my first probable sighting of a champion migrator.
Terns are closely related to gulls. I think of gulls as the basic Ford 150 pick-up truck—durable, tough, long lasting, but not too fancy. Terns are more delicate, can turn on a dime, and hover nicely in place, to me a bit more like Porsches.
In the Bay Area, arctic terns are usually seen far offshore during late summer and fall. They fly south from nesting grounds well north of the Arctic Circle all the way to southern Chile, traveling as far as 15,000 miles. In its average 25-year life span, an individual arctic tern may fly over a half a million miles. These terns spend more time in daylight than any other species on earth and were considered for many years the longest migrator on the planet.
Until, that is, researchers outfitted some sooty shearwaters with radio tags and tracked them for over 200 days. These albatross relatives leave their New Zealand breeding colonies and fly all the way to California to spend the austral winter in our summer. Here they feed just offshore on krill and squid in our nutrient-rich waters. In the fall they funnel back south to New Zealand, covering a total of more than 40,000 miles!