Date: 5/7/18 5:24 am From: Young, John (DPU) <john.young...> Subject: [MASSBIRD] All dark swallow 6 May Hanson
Late yesterday afternoon (6 May) at Burrage Pond in Hanson, I saw an almost all-dark swallow among a large flock of mostly tree swallows, along the dike between the pond and the old bogs, near the concrete foundation and forested island. It was either marginally larger than the tree swallows or the same size. It seemed to prefer their company but they seemed to harass it. There was a bit of whitish on the throat/upper breast and maybe on the flanks, but mostly it was a blackish brown color like the top of a dull female tree swallow or primaries of a bank swallow.
I would guess it was just some sort of over-pigmented tree swallow, rather than a runt purple martin, a super-dark rough-winged swallow, or some South American type, mostly because I couldn't distinguish the shape or flight action from the other tree swallows. Just a bird of interest; look for it if you're at the pond, and good luck!