A stroll along River Road, just upstream, brought me an opportunity to see some of the local regulars as well as some unusual migrants – all at the mouth of Grant Brook. Although the winter’s ice has just begun to recede, the critters moved in quickly. We saw some green-headed Mallard ducks, but also a pair of Mallards with vibrant blue heads:
Meanwhile, a beaver zipped by, then dove.
See the full gallery for more photos of both.
David Kotz 
A reader sent me two links about the color of mallard ducks – apparently, blue and green are two shades of the same iridescent phenomenon: https://www.natureblog.org/ducks-heads/
https://royalsocietypublishing.org/doi/10.1098/rsif.2017.0407