After a wonderful dinner with friends not far from Potter Marsh, we swung by to see what birds we could find. Note the official time of sunset tonight in Anchorage was 10:46. This picture was about ten minutes later.
And then I heard the unmistakeable croaking sound of a sandhill crane which flew over me, and I'm guessing disturbed the gulls and terns. They're huge birds - wing span about 6 feet, probably a little less than bald eagles (though the web shows a variety of wingspans for bald eagles.)
[UPDATE May 18, 2014 noon: Edgywytch comments below that sandhills eat tern and gull eggs. The Crane Foundation website linked below says:
"All cranes are omnivorous. Sandhill Cranes are generalists and feed on a wide variety of plant tubers, grains, small vertebrates (e.g. mice and snakes), and invertebrates such as insects or worms. Sandhills find these foods in uplands and in shallow wetlands. Like most cranes, flightless chicks forage primarily on a diet of insects and other protein filled foods during their early stages of rapid growth. The Sandhill's tendency to feed on plant tubers creates conflicts with farming. Sandhill Cranes are adept at probing in the ground and finding planted agricultural seeds such as corn. When large flocks of cranes feed on planted fields, the damage they cause to an unprotected crop can be severe enough to force the farmer to replant the entire field. "]
Sandhill cranes are another great bird we get to see in Alaska. You can read a lot more about them at the International Crane Foundation website. I had my telephoto on and finding the bird in my camera and focusing in the fading light was beyond my ability and I'm a little embarrassed by how fuzzy the bird is in the next picture, but it gives you and idea of how big it is. It's the white horizontal line in the picture. I'm guessing it's approach is what upset the gulls and terns. Since its wingspan is close to that of eagles, perhaps they originally thought it might be an eagle. But that's merely a wild guess - you'd think they should have learned to distinguish between the two.
It was pretty far away by the time I got this picture - about 11:05 pm.