As I started down the trail toward Spencer Island, the gurgling and raspy song of the Marsh Wren filled the air. Cattail patches are in the wetlands on both sides of the trail and at regular intervals I could hear a male wren declare loudly that this patch of cattails belong to him. Males in western Washington have a large repertoire of songs with more than 100 different ones. Adjacent males spend a great deal of time in vocal combat. Song is the primary way they defend a territory and having a territory is critical for attracting a mate. I saw several males actively carrying nesting materials. Males will build multiple nests as part of their effort to find a mate. A female may take one of these or may build her own nest once she picks a male. In Washington, Marsh Wrens are polygamous and a male with a prime territory may be able to attract more than one female.
On the boardwalk on Spencer Island, I watched for 30 minutes one male actively constructing its nest. The nest was woven between several cattail stalks about 2 feet above the water. The nest cup was complete and the male was working on building the dome over the nest to form the enclosed nest cavity. He flew down to the water to grab a strip of cattail leaf and carry it up to the nest where he proceeded to weave it into his structure. Jumping in and out of the nest as he pulled the strand to where he wanted it. Ever few seconds during this process, he would stop and sing loudly. After several trips with cattail leaves, he would fly to an old cattail spike which still had down and pull piece of down off to take back for lining the inside of the cavity. About every 5 minutes or so, the male would make a flight out to one or another corner of its territory, sing a few songs and then return to nest building. It takes them about 9 or 10 hours to complete a nest and they do this over several days. He was singing away as I finally walked on down the trail.
Spencer Island is protected and has several loops on dikes that you can walk around the marsh habitat. I watched several green-winged teal feeding in the shallows and a great-blue heron squawked and flew off as I rounded a corner. White-crowned Sparrows, Song Sparrows, and Spotted Towhees were singing loudly in the bushes along the trail. An Osprey sat on top of a dead snag and was quite picturesque against the blue sky. An adult Bald Eagle flew in at one point and scattered the teal. The walk was very pleasant and a nice way to spend the morning.