Date: 10/1/19 11:13 am From: Lars Norgren <larspernorgren...> Subject: [obol] Provenance of passerine migrants
Many common, widespread songbird species both nest in western Oregon and pass through here en route to more distant breeding and wintering grounds. The details of various populations remain unknown, and our assumptions unsupported. I suspect that Red-eyed Vireos, Hermit Thrushes, and Varied Thrushes being detected now are not local breeders, but arrivals from hundreds of miles to our north and east. The paucity of passerine detections in the Coast Range is of course an artifact of low observer effort. But the effort is to a large extent limited because experience has demonstrated that effort will not be rewarded . Heat units are low here (I 'm sitting in the silent D-firs and alders right now) and insects few. I left sunny skies and (rising) temperatures in the sixties at Tillamook on Sunday to drive through drizzle and sub-fifties in the Mountains to the east. Willows on the banks of the Willamette or shores of Yaquina Bay offer a great opportunity for migrants to put on fat.