Well, the return of the DBQ was a simple affair with only two mystery birds. The same day of the DBQ, capteagleeyes replied Bird #1 (aka Bird A) is a Black-Legged Kittiwake and Bird #2 (aka Bird B) is a Red-Breasted Merganser. A few days later, our very own SEANET Project Coordinator, Dr. Sarah Courchesne replied “I concur”. Lets review some key characteristics of these mystery birds and see if we can confirm their species identification.
Bird A looks tern or gull-like in winter plumage. However, none of the terns have a squared off tail. Most terns have distinct forked tails or some degree of forking in their tails. Thus, this directs us to the gull family (Laridae). Relative to the pebbles on the beach, this gull appears to be a smaller gull (less than 17″ total length). Next, bill and leg color are good clues its identity. The yellow bill points to Ring-Billed Gull, Common Black-Headed Gull (1st year, nonbreeding) or a Black-Legged Kittiwake. Bird A is lacking a black ring (Ring-Billed Gull) or a black tip (Common Black-Headed Gull) which leaves us with a Black-Legged Kittiwake.
Bird B provides us wings, feet and a sternum. I immediately look at the speculum (i.e. Secondaries) and the color of the webbed feet. Only two species of bay and sea ducks have solid white in their secondaries and secondary coverts. They are the female Red-Breasted Mergansers and the female Common Mergansers. The feet of the Common merganser are deep red in color. The male Red-Breasted Merganser has deep red feet as well while the female has lighter red feet. It appears to me the feet are a lighter red color in the picture. Therefore, we have enough clues without exploring the sternum that point to a female Red-Breasted Merganser.
There you have it. The evidence points to Bird A as a Black-Legged Kittiwake and Bird B as a female Red-Breasted Merganser, therefore, we can conclude the identification of the mystery birds are confirmed! Stay tuned for a future DBQ right here on the SEANET Blog.