The majority(but not all) online photo albums I looked at show N. ShovelerxCinnamon Teal hybrids showing deep cinnamon flanks extending completely over the breast. N. ShovelerxB-w Teal hybrids have paler & sometimes mottled breasts. The co-bird/ebird duck
discussed shows the flank becoming noticeably paler towards the breast, though breast is not definitively shown. Adult N. Shovelers can show a well-defined white crescent going into eclipse plumage in early fall(sub-eclipse--Madge & Burn, Waterfowl,
1988) which probably does not apply to cobirds duck dated 3-24-19.
I'm still leaning (but now not as far) towards N. ShovelerxB-wTeal hybrid. But perhaps the safest conclusion is to the leave unanswered the question re: cobirds duck: "Who's
yo' daddy???" ------- & maybe mommy too?
Dave Silverman
Rye CO