He was traveling with his squabble, (specieism alert! - hard-to-tell though, they all look the same), north to eastern Canada .
At first Jonathan was rather aloof and stand-offish. After warming to my presence he informed me they were of the genus Chroicocephallusa, one of the 10 species moved from Larus genera to differentiate them from the great black-headed gull. Jonathan added, with a hint of disdain, that the ornithological authorities, (homo sapiens !), have only recently become aware of the differences in the species. Then, with a "hi-yo SIL-verrr.", off they went.