I mistakenly ID’ed juvenile Song sparrows on Santa Cruz Island yesterday at Savannah sparrows. The eBird tool questioned the submission as rare, but I spent some time observing the birds and took some photos that I studied before submitting them. One of the factors I considered was that there was a pretty big flock of these sparrows. Another birder with me estimated up to 30 or more individuals in a loose flock mostly on the ground near the picnic area. I counted at least 12. Some of the birds were clearly newly fledged, tails not yet grown. I think of Song sparrows as not being in flocks like this, but after being corrected on the photo I submitted to eBird as juvenile Song sparrow, not Savannah sparrow, I did some research on flocking in juvenile Song sparrows. It looks like male juvenile Song sparrows do gather in “social groups” especially in the early summer, less so by late summer and fall. Here is a reference to this phenomenon. http://www.ncbi.nlm.nih.gov/pubmed/22479140

Here are photos of the birds: