Archive for the ‘National Wildlife Refuge’ Category

May 22

At the Edge of an Aspen Grove

The leaves on the quaking aspens rustled in the light breeze.

Rustling sounds filled the meadow while millions of small silvery flashes came from the copse. It was just a gentle breeze that morning but enough to make the leaves flutter. A pale green then green-silver would sparkle, and waves of these flickerings would transverse back and forth, like ripples moving across a small pond. No wonder these trees are called quaking aspens. 

A group of Tree Swallows flew around the nest box chattering away as they greeted each other.

A loud commotion came from my left. Just 20 feet away, a 6-foot high post had a birdhouse. Six chattering Tree Swallows were doing acrobatics within a few feet of the box. A pair had a nest there, and perhaps these others were trying to usurp the space. The birds never touched, but they came within inches as each twisted and turned. Their long pointed wings and broad tails providing precise control. Finally, one bird settled onto the roof, chattering lightly, and the others dispersed. At that point, I suspected this was some kind of social interaction, a morning greeting.

Tree Swallow

My attention turned to the aspen grove, and the bird I had come to find. The “chebec, chebec, chebec, ….” drifted from deep in the trees. The Least Flycatcher was singing. This species is in the genus Empidonax,a group of small, drab birds, which look virtually identical and can be reliably separated only by their songs. This individual, less than six inches long, was probably sitting on a branch four or five feet off the ground, scanning for flying insects, and giving its incessant territorial chant. The remarkable thing was that he was well outside his normal breeding range.

Sound Recording of the Willow Flycatcher singing.

I first saw this species in Western Pennsylvania when I was in high school. It breeds north from the central Appalachians through Canada and west to the Rockies. A few breed in northeastern Washington, but this site at Conboy National Wildlife Refuge in south-central Washington is hundreds of miles out of its normal range.

I was curious to find this bird for I had a strange feeling of connection to it, almost like this little guy was a brother. Except for undergraduate school, I’d spent my first 60 years living in Eastern United States before moving west to Seattle. Since settling here, I’ve felt both out of place and yet extremely content. The flycatcher, also, didn’t seem to care if it was far from its regular haunts. Several dozen birders had heard his song over the last week. He was apparently here for the breeding season.

My left hand clutched the parabolic microphone pointing toward the sound, while my right hand held my binoculars in the ready position. The digital recorder was running while I searched the understory for this elusive bird. No one was allowed anywhere beyond these trails, and if I didn’t want human-made sounds in my soundtrack, I couldn’t move. My best chance to see this individual was if it flew and landed on a visible branch. 

White-breasted Nuthatch
Red-breasted Sapsucker

Other birds were also singing on this early June morning. The elaborate warbles of a house wren came from the understory to my left, and a warbling vireo’s slurry notes drifted through the quaking leaves above me. White-breasted Nuthatches, Red-breasted Sapsuckers, Western Bluebirds, and Western Wood-Pewees also made their presence known. Headsets covered my ears, giving me a stereo concert of this forest patch at the edge of the wet savanna that covered most of this Refuge.

Suddenly, I realized a second Least Flycatcher was calling off to my left, so I turned the parabolic reflector in that direction to see if the sound would become more distinct. Yes, it definitely was a second individual. Both sexes sing in this species. The first part of the female’s “chebec” is slightly lower in pitch, but the second part is virtually identical. Males, though, are not evenly dispersed through suitable habitat but rather form clumps of small territories. It is like a classical lek system where the males all compete for females on a stage rather than be spread throughout the theater. My ears weren’t discerning enough to decide if this was a pair or two separate males. 

They have an exciting display, but I was there at the wrong time of day. For a short period after sunset, the male will climb up through the branches to the top of the canopy offering warbles, whits, and chebecs as he goes. He then performs a “flight song.” He flies up from the treetops for 30 seconds, singing non-stop, and then tumbles back down, much the way a butterfly might flutter. Of course, ornithologists think it has something to do with mating, but we don’t know the actual function of this flight song. In my imagination, I can only assume that the male goes high to become visible to a distant female who might be wandering through looking for a mate. 

A flash of brown zipped behind an aspen trunk and then landed on a dead branch a few feet off the ground. The Least Flycatcher looked off to my right, gazing up and down into the small opening under the aspens. A second later, he was gone, but a surge of energy stayed with me. This bird was living life wherever he was. 

The Aspen Grove at Conboy National Wildlife Refuge.