On the second (or, rather, the first) specimen of the recently described Calliophis salitan (Squamata: Elapidae), with the first report of the species from Mindanao Island, southern Philippines

Abstract. We report on the second known specimen of the recently described banded Asian coralsnake, Calliophis salitan, identified among the Museo Nacional de Ciencias Naturales collections of Dr. Hipolito Fernandez, made in 1886. The specimen was collected on Mindanao Island in the southern Philippines as part of the “Comision Central de Manila,” the Spanish Crown’s effort to catalogue and showcase Philippine biodiversity for the Madrid public. We assign this important specimen to C. salitan (formerly known from a single specimen collected on Dinagat Island) based on its highly distinctive external phenotypic characteristics (scalation, body size, and inferred colour pattern). The discovery of C. salitan on Mindanao significantly extends the known geographic range of this species and partially fills an intermediate distributional hiatus – a large geographic gap in the distribution of large-bodied, long-glanded coralsnakes. This report partially resolves a biogeographic enigma surrounding the question of how a distinctive evolutionary lineage of elapid snakes – more closely related to the Calliophis bivirgatus group from Borneo and other landmasses of Sundaland than to any other Philippine elapids – could have colonized only a small island (Dinagat) in the geographic interior of the archipelago. The answer appears, most likely, that this dispersal occurred over land, via the large intervening island of Mindanao. Although the exact site of collection is unknown, consideration of the collector’s itinerary suggests that it originated most likely in the vicinity of Davao City, southeastern Mindanao. Its discovery confirms that C. salitan occurs on Mindanao (or, at least, did occur on this island as recently as 133 years ago), and that locating additional populations via targeted surveys is an urgent priority for conservation of this remarkable Philippine endemic snake lineage.