What animal sees the most daylight and has the longest migration of any on earth? This would be the Arctic Tern, recently back to Alaska and from Antarctica.
Sleek and swift, their body styles are fitting; terns look the part of a long-distance athlete and their wings cut through the air as if by magic.
Even after a pole-to-pole migration, the birds spend most of their time on the wing, diving and eating in the air, even sleeping aloft with one eye open.
Fuel comes in the form of small baitfish, insects and other invertebrates. Local terns spend a lot of time feeding in the rich waters near the mouth of the Mendenhall River. The Airport Dike Trail can also be a great place for tern watching, as riotous feeding groups of terns and gulls make a gauntlet for small fish, like capelin (a small fish resembling a smelt), in the spring.
Locally, Arctic terns are the most common tern. The Fish and Wildlife Service estimates there are about 11,000 statewide.
However, Alaska hosts a similar size species, the Aleutian Tern that can be seen around Glacier Bay. Often, the two types of terns may be in the same area, living a similar summer life.
They take radically different routes in the late summer.
Aleutians have been observed over coastal waters of Java, Bali, and Sulawesi. While the specific route of Alaska Arctic terns are not well documented, the most likely route takes them south along the Pacific, and crossing the Andes between Chile and Argentina before heading to Antarctica, a distance of at least 9,500 miles from Juneau.
A third species of tern, the Caspian, is rare in Southeast Alaska. These birds dwarf the others, being about the size of a large gull. But the narrow wings, bushy crest, and bright red bill set them apart. Even at a distance, they resemble a prehistoric dinosaur-like flyer.
And, they may be becoming more common locally. Thousands of Caspian terns nest on an island near the mouth of the Columbia River. A bird banded as a chick at this colony, in 2004, was seen by local bird watchers last July on the Mendenhall wetlands. Pacific Northwest birds may be straying as far as Alaska because of changing marine conditions and an increase of bald eagles down south is making nesting there more difficult. Researchers believe these factors could be causing these terns to seek out new areas.
Two of these Caspian terns were observed recently near the mouth of the Mendenhall River.
When it comes to nesting, terns seek open, flat areas near water, especially islands where fewer predators lurk, to make a simple scrape on the ground for the eggs.
One of the best places to observe nesting Arctic terns is near the Mendenhall Glacier Visitor Center. Photo Point offers a view right into the nesting zone for a colony of about 100 birds.
Welcoming the migrants back to Juneau from their long journeys will be one of the activities planned by the U.S. Forest Service and other local groups for International Migratory Bird Day.
Learning about terns can capture the public imagination, and hopefully inspire further conservation.
During summer months, the nests are vulnerable to disturbance. It is community vigilance that keeps them safe from foot traffic. Terns have nested near the glacier since 1945, and hopefully will continue to follow the sunlight to Juneau each spring.
• Gwen Baluss has been studying Juneau birds for work and fun since 1998.