There were numerous of these perched on interpretive signs at the far (awat from ocean) end of a dry salt marsh with many native plants, but next to a subdivision.

Curiously of everything I shot yesterday, Lightroom seemed to have real trouble rendering the EOS 50D raw files only from these flies. I'm not sure why. The normal Canon presets just made these brown and dark, neither of which was the case in the field. General - Zeroed and then some manual tweaking got it to this, which is a reasonable rendition of the actual colors, and a much more legible photo.