Hiram and Baldwin: Swainson's, Nighthawk, NRWS, more warblers & a mystery shorebird (ID Help requested)

[Sean S]

In Hiram today a Swainson's Thrush was seen in a yard, making repeat appearances throughout the day.  Photos: https://ebird.org/view/checklist/S56495813

At Ingalls Pond Railroad Trail (adjacent to the Saco River in Baldwin) were a Common Nighthawk, a Yellow-throated Vireo and 2 Wilson's Warblers.  Also 4 Northern Rough-winged Swallows that showed up around 6 pm...2 of them were trying to mate while an Eastern Kingbird aggressively pursued them in circles, driving them to hide in the trees several times.  Additionally, if anyone can help with a shorebird ID it would be greatly appreciated: there was a chunky, pigeon-like plover (or something) that was seen and distantly photo'd with 2 Spotted Sandpipers on a small mudflat at Ingalls Pond.   It didn't look like a Semipalmated, had a rounded head, fairly short bill and an odd rolling gait to its step, larger than the Spotteds.   The distant photos I could manage to get (with cropped enlargements) are in the following list.    Wish I had brought a scope today but wasn't expecting shorebirds.  Maybe someone can nail it?  Thanks for any help.

List:  https://ebird.org/view/checklist/S56514677

Sean Smith