However, the most interesting bird of the trip was a mystery landbird which made a brief pass of the boat, flying toward shore about 4 miles out. Dozens of folks, myself included, saw this bird make a pass as close as 100 feet from the boat. We had a very solid look at it, with good lighting (though the boat was rocking), before it got away from us and into an area of backlighting. The high quality look lasted about 4 seconds. All of us had only binoculars, but thankfully one participant, Zak Pohlen, was able to capture the bird with his DSLR/telephoto rig. Here are Zak's best photos, greatly cropped (he got 7 exposures in total, with 4 in focus enough to use):
The bird was clearly a landbird, and pale gray overall. All who saw it thought it was roughly in the size category of a starling, blackbird, or meadowlark. It was flying quickly and aggressively toward shore, into a steady headwind, and making good progress. The wingbeats were fast, interrupted by bouts of gliding, like a meadowlark. The initial discussion among the birders on deck was of it possibly being a kingbird, starling (esp. a pale juvenile), or even a meadowlark. But once back on land and looking at Zak's photos some additional traits began to emerge and the discussion moved toward a pigeon or dove. But after looking at all the options in this group, none seemed to match well enough to call it, so we eBirded it as a pigeon/dove sp.
Our discussion of the pigeon/dove options went like this: we considered Eurasian Collared-Dove (still very rare in MI), as it seemed to match the overall color of this bird but my judgment was that the wingbeats were too fast and that it was to small to be that species, plus the upperwings appeared wrong. Common Ground-Dove, accidental in MI, was discussed, but the apparent amount of white in the tail corners was thought to be too large, and the tail possibly too short (?). Inca Dove, also accidental in MI, has subsequently been mentioned by some, and may still be a viable candidate (?). A final discussion revolved around whether this could just be an aberrant Mourning Dove, with some kind of symmetrical tail molt making the tail appear perfectly squared, and overall pale coloration. Of course, several traits seemed at odds with this identification as well, including the very pale coloration and relatively large head. Of course, the quality of the photographs is a limiting factor here, and may be distorting some of these traits.
To summarize, this bird may well go down as unidentified, but myself and most of the birders on the boat would love to know what everyone thinks, and either way a good mystery bird is always a lot of fun anyway.
Here are the originals for anyone interested: