Red-breasted Mergansers on inland waterbodies in Contra Costa
Today there were female type Red-breasted Mergansers at Mallard Reservoir and Ellis Lake Park in Concord. I saw them a couple hours apart, and these locations aren't too distant, so not sure about the possibility of these being the same bird. The latter location certainly surprised me given the small size of the lake compared to where I typically see this species.
Other highlights for Mallard Reservoir included a Tundra Swan and two Caspian Terns. Many waterbirds were present and taking advantage of the range of water depths including exposed mud in the southeast corner adjacent to Bates Ave where viewing is possible. Unfortunately I did not have time for a thorough tally of all species present.