A Tale of Two Tortoises
In a ZooKeys article published this year, Academy curator emeritus Alan Leviton and colleagues, collaborating with Dr. Robert Murphy of the Royal Ontario Museum, solved the identity crisis of the desert tortoise Gopherus agassizii -- a saga almost as old as the Academy itself. First, by sifting through the original species description in The Proceedings of the California Academy of Natural Sciences (as the Academy used to be called), they determined that the species was first described in 1861, not 1863 as had long been thought. Next, they deduced that one of the three original specimens used to describe the species was likely lost during the most devastating event in the Academy's history -- the 1906 earthquake and fire. (A second specimen is currently housed at the Smithsonian, while the whereabouts of the third remain unknown.) Third, they reviewed the tumultuous taxonomic history of the species, which has changed its genus name five times in the past 150 years. Finally, using DNA analysis, they concluded that G. agassizii is not one, but at least two distinct species -- one that lives to the northwest of the Colorado River in California and Nevada (G. agassizii), and one that lives to the southeast of the river in Arizona and Mexico (a new species, which they named Gopherus morafkai).
This newfound clarity has important implications for conservation, because the geographic range of G. agassizii is now only 30% of its former range. Having significantly declined in numbers over the past three decades, it may warrant a higher level of protection than its current "threatened" status. And now that G. morafkai has a distinct name and its own identity, its conservation status can be evaluated as well.
