Recently, I had stumbled upon a photograph I had taken of a flock of lesser snow geese flying over a marsh in Southwest Louisiana. I searched my bird field guide for the scientific name of our beloved snow geese and found “ Chen caerulescens” in my guide published in 1994. As any good biologist would, I double checked my printed resource with a digital one. Much to my surprise, I found conflicting results. Some sites used Chen caerulescens while others used Anser caerulescens as the scientific name for the snow goose. Hmm…. Differentiating genera; how could this be? Scientific names are universal, so it had nothing to do with exceptionalities between my Eastern Region of North America field guide and European based websites. Perhaps there is a subtle name change between the lesser and greater snow goose? Nope, the results again did not match. Okay, I was stumped. So I reached out to an old professor friend… and there I found the answer:
“…Looks like the Genus of snow geese went through a recent revision. It appears that Anser is the most accepted now. But since it used to go by Chen you’ll still see it in some publication. In taxonomy it is called a synonym.”
Since the Snow Goose has a blue and white morph or phase, the taxonomic location of the species’ genus position is conflicting among authorities… or as an old professor of mine would call it, “The Taxonomy Gods”. It seems that Linnaeus placed the Snow Goose in the Chen genus meaning “white geese” in 1758. However, in recent years, scientists have used the genus Anser, which simply means “goose” followed by the species name of caerulescens which means “blue”. This confusion of genera may be due to the fact that the two phases were once thought to be two separate species.
What is the final lesson here? Science is always improving! That is why I love it! As we become more educated, we are able to make more accurate classification decisions. It is noteworthy that a true taxonomic name and its synonym may differ between scientists based on the scientific situation being written of… just in case you were not confused already. For example, while writing this article I used a textbook reference written by Guy Baldassarre. Baldassarre, who passed away in 2012, was a true expert of his field. He uses Linnaeus’ original name for the Snow Goose, Chen caerulescens and notes the preference to use Anser by other authorities.
References:
National Audubon Society. “Snow Goose including "Blue Goose".” Field Guide to Birds Eastern Region, Alfred. A Knopf, Inc., 1994, pp. 385–386.
Hoffman, Justin, and Sara Douga. “Snow Goose Taxonomic Synonym.” 28 Feb. 2018.
Baldassarre, Guy. “Snow Goose (Lesser and Greater).” Ducks, Geese, and Swans of North America, vol. 1, Johns Hopkins University Press, 2014, pp. 131–137.
“Snow goose.” Wikipedia, Wikimedia Foundation, 3 Mar. 2018, en.wikipedia.org/wiki/Snow_goose.
“Synonym (Taxonomy).” Wikipedia, Wikimedia Foundation, 4 Mar. 2018, en.wikipedia.org/wiki/Synonym_(taxonomy).