Hi Anyone & everyone, I know this is long shot but I saw a bird yesterday (4/3/19) afternoon in NYC, midtown, 50th St & Broadway. It was about the size of a small seagull but not a seagull as the beak was too small. All white on the back & body but had blue color on the underside of the wings, a longish neck and the most striking thing was the colored ring that went fully around the neck that had what seemed like the most perfectly shaped bright green ovals each with 3 or four black dots within each oval. I'm kicking myself that my phone was on my desk when I stepped out for a second and when I got within about 10 feet to get a better look it took off and flew atop the building across the street. I've been looking for it out my window every chance but I haven't seen it return and probably won't at this point. I've been scouring over pictures on the web since I saw it and cannot find anything that looks really like it. Also wondering if the ring around the neck could be a one-off mutation or something along those lines? Any help would be appreciated.