When Taxonomy Makes a Species Less Critically Endangered

The story of many San Francisco butterflies are well known and depressing. The area has been heavily impacted by human development for over two centuries and is the infamous home to the first known example of an extinct American butterfly, the Xerces blue. While other butterflies are hanging on, or getting help to hang on like the Mission Blue, some like the Bay Checkerspot have continued to decline despite valiant efforts for reintroduction. Today, the only known colony of the Bay Checkerspot is within Santa Clara County on a site called Coyote Ridge. It was twenty one years of intensive study of the checkerspot in the 1960’s and 70’s by the famous biologist Paul Ehrlich that provided the impetus for federal listing in 1987. As of 1998 the colonies he studied have since gone extinct. Here is an excerpt from a 1980 paper in the Journal of the Lepidopterists’ Society “Two California Checkerspot Butterfly Species, One New, One on the Verge of Extinction” (.pdf).

“The Bay Checkerspot is already an endangered butterfly. This sad situation is all the more distressing since its populations are among the best known – ecologically and genetically – of any invertebrate. We are attempting to get official protection for E. e. bayensis and are designing some experiments to recolonize areas of suitable habitat that are now vacant.”

Bay Checkerspot Bill Bouton

All efforts to relocate this butterfly have failed, and the future of this animal is not looking bright.

And so what exactly is this creatures name? In 1937 Robert F. Sternitzky described what he thought to be an overlooked San Francisco butterfly “Euphydryas editha var. bayensis“. Those early descriptions of variations and races are roughly equivalent to today’s subspecies – and so the butterfly remained bayensis for decades and became a mascot for conservation. But where was the very first Euphydras editha from and how did the San Francisco bayensis differ? Unfortunately the original description is vague and the collecting locality is simply listed as “California”, as was the unfortunate habit of Boisduval who described the butterfly 1852. But all hope is not lost since the famous French Lepidopterist was having specimens sent to him by the earliest California Lepidopterist, Pierre Joseph Michel Lorquin. An eager gold prospector and butterfly collector, Lorquin traveled California from 1849 to 1858 and again in 1869. Every butterfly that was sent back to France was a new species and subsequently described by Boisduval – who of course named one of California’s most beautiful butterflies after Lorquin.

Enter Emmel, Emmel and Mattoon in 1994 who were writing the Systematics of Western North American Butterflies. In the process of cleaning up the mess of these early western species they had to designate a Lectotype for E. editha editha since Boisduval never fixed a Holotype in 1852. Essentially he named a new species without designating the taxonomic standard for the group, making future work ambiguous for taxonomists. Thankfully the travels of Lorquin have roughly been documented and we can ascertain that he should have been in San Francisco around 1849. Comparisons of the original specimens to the Bay Checkerspot made for an overwhelming case that it was this butterfly that was sent to France in the 19th century. The result of this finding therefore places the Bay Checkerspot Euphydryas editha bayensis into synonymy with the older name Euphydryas editha editha. The name bayensis effectively dissappeared because it was a re-description of a butterfly that was already known.

Euphydryas e. editha as it turns out has been known from coastal California from the bay region down to San Luis Obispo – and so voila, the range of the Bay Checkerspot just exploded. But of course the story isn’t that simple and the butterfly didn’t become magically safe with a name change. Conservation groups and ecologist kicked and screamed and refused to accept the change, even the Xerces Society hasn’t jumped on board with the consensus of taxonomists out of what I can only assume is fear of the appearance that their butterfly is no longer endangered.

I’ll emphasize that this doesn’t mean that the populations in the bay are no longer threatened – there is still a need for protecting these biologically significant populations as they are significantly declining. Habitats all throughout the region are facing ongoing and pernicious threats (pdf). All in all the name change is trivial, we can now call the Edith’s Checkerspot the Bay Checkerspot, and still fight to protect this butterfly. I’m unsure of what would be required to amend the federal register, and if it’s at all possible to expand protection of an animal like this without re-petitioning the endangered species act. So perhaps I can understand the failure to embrace the name change since from the outside it looks like their bug is no longer endangered. On the other hand, this could bring attention to populations of a butterfly that have been overlooked for decades.


Many thanks to John Pelham for conferring with me over this taxonomic headache.



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