Before looking for uncommon or rare birds, one needs to become familiar with the common species. When you know the common birds well, uncommon birds will stand out, especially if you put the time in to find them. In this case, Tim Carney, an avid Maryland birder, found what originally appeared to be a Tufted Duck. Before pulling the whistle on this rarity, he studied it further and suspected that it may be a hybrid since the back wasn’t dark black. After sending photos to experts (other Maryland birders and the fine folks at eBird), the ending consensus is Tufted Duck x Lesser Scaup. I’ll try and walk through some of the key identification points accompanied by a suite of Tim’s photos.
From this angle and distance, the bird looks decent for Tufted Duck, but notice the paleness to the back (towards the head) and the flanks are kind of dingy. A pure Tufted Duck would have a dark gray back and pure white sides. Lesser Scaup features in this photo include a small bill and the head is not rounded, as it would be in a Tufted Duck. In all three photos, you can see grayish back and non-rounded head.
In this photo series (bird is near the center) the dark gray back, rather than dark black is evident. Since the bird is tucked, other features are not obvious, but this just shows that even with a sleeping bird, diligently studying the characteristics in view can lead to a conservative identification. In this situation, it definitely does not look right for Tufted Duck, but I would wait until it was untucked before pulling the trigger on an ID.
This hybrid has only been recorded in eBird on two prior occasions, one from Colorado in 2012 and another from Newfoundland and Labrador in 2015.
Check out the following links for photos and information on Tufted Duck x scaup hybrids.
Also, I found this interesting excerpt from McLaren and Nova Scotia Bird Society (2012) regarding Tufted Duck x scaup hybridization in Nova Scotia:
Hybridization with Greater Scaup is known in Iceland, and three or four such hybrids have been reported here, two photographically confirmed.
Male hybrids with Greater Scaup have stubby tufts and vermiculations (narrow, wavy barring) that may be hard to see on the dark grey back; female hybrids would be more difficult to identify.
As birders, we should always be on the lookout for birds like this, because hybrids can give us insight into breeding dynamics of closely related species and the identification challenge is always fun!
McLaren, I. A., & Nova Scotia Bird Society. (2012). All the birds of Nova Scotia: Status & critical identification. Kentville: Gaspereau Press.