In 2010 the winter wren (Troglodytes hiemalis) and the Pacific wren (Troglodytes pacificus) were recognized as two distinct species. Previously both new species were known as a single species: winter wren (Troglodytes troglodytes). According to Sibley Guides, there are no significant differences in size or shape between the new species. There are subtle and overlapping differences in plumage. The best way to distinguish the two birds is by their voice, especially the call, not the song. I even read the statement that identification of individuals by photographs may be impossible. Range may be the best clue to identification. Arg!!!
The Pacific wren is not as migratory as the winter wren and is present year-round in much of the Pacific Northwest and California. This tiny wren is reclusive and concentrates in cool, shady evergreen forests, preferring firs and spruces. Pacific wrens forage for insects and spiders on the ground and along the banks of streams. In cold weather they will roost in groups.
A good field marking to separate the Pacific wren from other small wrens is the very short tail that is often held upright. Pacific wrens have brown underparts with faint barring, dark brown upper parts with strong barring and a buff eyeline.
Pacific wrens are very difficult to see and are in constant motion.
This Pacific wren was photographed along the North Umpqua Trail in Oregon.