Arctic terns (Sterna paradisaea) travel over 12,000 miles annually between their winter home in Southern South America and Antarctica and their nesting range in Alaska. They have been known to nest on Mendenhall Lake since at least 1978.
Terns often nest in colonies or groupings of several nests. They prefer areas with sparse vegetation near water, and the beaches created by the retreat of the glacier are good habitat for them. About 80 birds frequent Mendenhall Lake in the summer, although only a few of them successfully breed. The young birds will be ready to fly south by mid-August.
The birds can be viewed from the Photo Point trail diving for small fish and touching down on the sand bar. Juneau is one of the only places in the world that observers can get so close to a breeding colony of Arctic terns without disturbing them. The ground nests are well camouflaged, but a little patience may yield a look at the nestlings through binoculars.
The Forest Service asks that viewers heed the temporary signs around the colony because the nests are difficult to see and are at risk for accidental trampling, and to leash dogs when hiking toward Nugget Falls.