Monday, January 31, 2011

Winter Shorebirds of Budd Inlet

A few days ago Glen and I were taking a walk along East Bay in Olympia. This is the southern terminus of Puget Sound, where Indian and Moxie Creeks pour their waters out, and feed nutrients into the East bay estuary. We happened to take our walk at extreme high tide, and only the boiling turmoil on the surface of the bay showed the outlet of the creeks.

As we walked along, Glen remarked on the squeaky sounds of birds, and pointed out some American widgeons in the distance. Then he stopped suddenly as he realized he was wrong, and showed me a group of birds perched on some rocks just below us: a flock of Dunlins, shorebirds that spend their winter lives around the estuaries of Puget Sound. Here, ten feet away from us, was part of a resident flock in Budd Inlet making their peep noises of alarm.

Dunlins are shorebirds, which means they spent most of their lives on muddy tidelands, probing those long bills into the fine silty muds, seeking by touch a wide variety of polychaete worms and arthropods. They feed as long as they are able throughout the tidal cycle, but once the incoming water covers the mud flats that are the dinner table, they retire to some safe perch. This is their high tide roost, and here they digest, preen out their feathers, take a quick nap and wait out the tide, watching the fall of water that signals that the dinner table is available once again.

Notice how well their color blends into the surrounding rocks. This is no mistake; they blend beautifully into their surroundings and if they hadn’t made their alarm calls, Glen and I would never have seen them. A safe high tide roost is a necessity, as these birds are the favored prey item of Peregrine falcons, Merlins and pretty much any other hawk that can catch them.

The location of the roost is no mistake either; just below these rocks are the highest mud flats in East Bay, and as the tide turns and drops, these are the first mud flats available to the Dunlins.

Shorebirds are notoriously hard to identify, especially when they are in their drab winter plumages. How do we know these are Dunlins? Some key identification marks include dark legs, dark long bill and dark eyes. The long bill has a characteristic slight droop at the tip. In winter they are a uniform brown; their heads are very round and the dark eye is like a bull’s eye in the middle of that round head.

If you look carefully at the feathers on the backs of many of these birds, you will notice they are very faded and worn around the edges. These birds molted in new feathers last July, while on the breeding grounds in Alaska and in preparation for their long migration flight south to Puget Sound. By now, through many months and the storms of winter, those feathers are both faded and very ratty around the edges.

However, some of these birds are juveniles; born last summer, they molted in a different way and in a different timing, and so their feathers are more fresh. Here you can see a bird of the year, with a few dark, gold-rimmed feathers on its back, and the gold-rimmed flight feathers below. This bird has not yet seen its first birthday, yet it has made it through the long flight south, and the hard winter. It is a miracle of survival.

Over a long and varied life as a naturalist, I have spent many many long days sitting on the mud flats, watching shorebirds as the incoming tide pushes them in. Some of the best memories of my life are these vigils in the wild places, my butt planted on cold sand, beach grasses whipping my face, the calls of wild birds filling my ears. There is a feeling that if I wait long enough, quietly enough, the tide will push the flock all around me and I too will become one of the wild migrants, travelers from an unknown land, making my living on the rich dinner table that is a muddy estuary. Such is the beauty and magic of shorebirds.

Janet Partlow
Resources: Photos by Nancy Partlow

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