ML646532851

Observation details

Continuing in and near the same small green ash (46.84158, -114.06554) where William Blake found it yesterday, bark-gleaning on the trunk and sometimes branches, disappearing for a time, and then returning to the same tree. At times flew across the slough to a willow on the other side. Seen early in the observation period with a mixed flock with almost exactly the same composition observed last night - several OCWA and WCSP, a couple of COYE, and a RCKI - suggesting that not just the PROW but also most of its associates didn't move on overnight from this evidently productive foraging area. On the return around 1130-1200, I again saw the PROW foraging in the same tree. I was curious what sort of invertebrates these birds might be finding on the ash bark, so I set up my spotting scope and zoomed in on the trunk. There were numerous winged woolly aphids (Aphididae: cf. Eriosomatinae) present, although when I observed the PROW foraging through the scope I was unable to get definitive confirmation that the aphids were indeed its prey. (However, photos from yesterday by Steve Flood, Thomas Kallmeyer, and Radd Icenoggle confirm that this bird has been gleaning woolly aphids from the trunk.)