Most of the time, the head of a male Mallard definitely appears green.
However, if the light strikes it a certain way, it can appear blue.
Or the colour can be mixed.
Other birds today at Lambton Woods:
Bird Species list: double-crested cormorant, great blue heron, Canada goose, mallard, red-tailed hawk, turkey vulture, ring-billed gull, herring gull, hairy woodpecker, blue jay, American crow, black-capped chickadee, white-breasted nuthatch, red-breasted nuthatch, European starling, American robin, ruby-crowned kinglet, golden-crowned kinglet, house sparrow, common grackle, red-winged blackbird, northern cardinal, American goldfinch, song sparrow. (24 species)
We also glimpsed a bunny:
and had plenty of sun:
10 am group:
1 pm group:
Listen! The wind is rising, and the air is wild with leaves,
We have had our summer evenings, now for October eves! – Humbert Wolfe (1886–1940)