Dawn Chorus along Stossel Creek

The marsh along Stossel Creek in Western Washington had a wonderful dawn chorus in early May.
Wetland along Stossel Creek.

Droplets bounced from bow to bow, making light ringing sounds as they fell through the Western Hemlocks and Red Cedars. Although it didn’t appear to be raining right then, the built-up water in the trees still tumbled. Water in the Red Alders gave a little different sound in this pre-dawn light, but the songs of hundreds of Pacific Chorus Frogs dominated the dark. A wide, slow-moving portion of Stossel Creek extended for a hundred feet or more in front of me. There, grasses, bushes, and small trees grew in the wetland, the perfect habitat for these tiny anurans. The males will climb a grass stem or twig, puff out their gular sack and let forth with that song. Within five minutes, a Common Yellowthroat added its “witchy witchy witch” to the dawn chorus, and shortly an American Robin began his melodious song. The area was getting lighter, dawn was happening.

The Dawn Chorus along Stossel Creek a mile or two north of the Big Pond.

It would be another five minutes after that before I heard the long, raspy whistle of a Varied Thrush. His note lasted almost a second and stayed all at the same pitch; then, he paused before giving another note at a higher pitch. He continued this pattern, long pause, long note, either higher or lower than the previous, always different than the immediately prior one. For me, this bird symbolizes the thick coniferous forests, especially at mid-elevations, of Western Washington. I wasn’t sure they would be at Marckworth Forest in May, so this was a special treat. Their tune gives me an eerie feeling, one also of mystery and intrigue. Hearing it always fills me with envy, for I wish my house were among thick, giant conifers such that this bird sang around me each spring. But I’d found one and my heart rose with delight.

It was mid-May, and many residents and early migrants had begun breeding. Other migrants would be arriving from their southern wintering grounds over the next few weeks. The Common Yellowthroat winters well south of Washington but had come back in April. A Song Sparrow and a Red-winged Blackbird gave their unique melodies to this morning ensemble. The sparrow probably stayed here all winter, while the blackbird might have wandered in western Washington before moving back to these marshes.

The forests in the Stossel Creek valley are filled with Western Hemlocks, Western Hemlocks, and Douglas firs. It is wet forest typical of the Pacific Northwest.
The forest along Stossel Creek.

Behind me, the high pitch song of a Chestnut-backed Chickadee drifted in, and the energetic trill of a Pacific Wren filled the forest with cheeriness. Unfortunately, I’m losing my ability to hear the high notes of the chickadee. Age is catching up to me. Soon I will need to seek a hearing aid to continue listening to these birds, for spring without them is unthinkable. 

A Steller’s Jay gave his rattle, and I looked down to see what my phone thought had been calling. Last year, Cornell Laboratory of Ornithology added song recognition to their Bird Identification app, Merlin. They had volunteers go through thousands and thousands of recordings, marking which songs belong to what species, and then used machine learning to teach the app. They even used a few recordings I had made. The app said that a Northern Flicker and a Sora had called, but I hadn’t caught either in this morning’s chorus. 

I’d been there almost 40 minutes when I shut down my recorder and wondered what the chorus here might be like in another few weeks when more migrants had arrived, and some of the residents might be less vocal as they concentrate on raising young. I’ll have to come back again. 

Anuran Chorus at Stossel Creek

Pacific Tree Frogs were in full chorus, and a few American Bullfrogs added to the performance. The marsh system along Stossel Creek provides ideal habitat for these species.

The frogs were in full chorus. Swamp stretched across the valley for a hundred yards and for a half-mile along Stossel Creek. A mixture of willows and grasses grew in the wetlands, and then a pond opened downstream from this spot. The loudness and diversity of their songs made me think that hundreds were singing simultaneously. These were Pacific Tree Frogs Pseudacris regilla, and I was trying to absorb that a tiny anuran, less than 2 inches long, could make that much sound.

They also go by the name Pacific Chorus Frog and hearing this choir made me think that chorus frog might be a better name. When one male begins to sing, any nearby male will jump right in and try to outsing the other. Each puffs out its vocal sack as it puts forth the song. This was not an organized chorus with all of them singing together, but rather each male was trying to out-compete the next. If he succeeds, a female may come his way. He needs to sing louder or differently to entice her to pay attention to him. 

In the distance, I noticed the deeper and more resonating call of an American BullfrogLithobates catesbeianus. This introduced species is a severe problem in Washington. The Washington Department of Fish and Wildlife has listed it as an invasive species. Bullfrogs grow to be big. With their legs stretched out, they can be up to ten inches long and are voracious predators, eating anything they can catch. They were natives in Western Pennsylvania, and I searched for them along the shoreline of ponds near my parent’s farm. 

At fifteen minutes into my recording, a lull of ten seconds happened. Perhaps, one male needed a break to catch a snack, and all the rest followed, but I suspect it was more likely that one sensed a possible predator nearby, and they went silent. Eventually, one male frog couldn’t resist and croaked. The rest then started back up. Barred Owls are common in these lowland forests of the Pacific Northwest and will hunt these frogs. 

Tree frogs need to breed, though; these anurans sing even if it exposes them to the risk of being eaten.