Saturday, December 19, 2020

[Herpetology • 2020] Phylogenetic Relationships and Biogeographic Range Evolution in Cat-eyed Snakes, Boiga (Serpentes: Colubridae)

  Boiga melanota Boulenger, 1896
from southern Thailand

in Weinell, Barley, Siler, ... et Brown, 2020. 
The genus Boiga includes 35, primarily arboreal snake species distributed from the Middle East to Australia and many islands in the western Pacific, with particularly high species diversity in South-East Asia. Despite including the iconic mangrove snakes (Boiga dendrophila complex) and the brown tree snake (Boiga irregularis; infamous for avian extinctions on small islands of the Pacific), species-level phylogenetic relationships and the biogeographic history of this ecologically and morphologically distinct clade are poorly understood. In this study, we sequenced mitochondrial and nuclear DNA for 24 Boiga species and used these data to estimate a robust phylogenetic inference, in order to (1) test the hypothesis that Boiga is monophyletic, (2) evaluate the validity of current species-level taxonomy and (3) examine whether geographic range evolution in Boiga is consistent with expectations concerning dispersal and colonization of vertebrates between continents and islands. Our results support the prevailing view that most dispersal events are downstream – from continents to oceanic islands – but we also identify a role for upstream dispersal from oceanic islands to continents. Additionally, the novel phylogeny of Boiga presented here is informative for updating species-level taxonomy within the genus.

Keywords: Boiga flavescens, Boiga multomaculata, Boiga dendrophila, dispersal, Philippines, South-East Asia, Sundaland, systematics, Wallace’s Line, Weber’s Line

Photos: Ishan Agarwal (Boiga beddomeiB. trigonata and B. ochracea), Kin Onn Chan (Boiga melanotaB. drapieziiB. cynodon and B. cyanea) and Perry L. Wood, Jr (Boiga multomaculata).

Boiga cynodon (F. Boie, 1827) 

Boiga multomaculata (F. Boie, 1827)
Photo: Perry L. Wood, Jr.

Boiga ochracea (Theobald, 1868)
Photo: Ishan Agarwal 

Boiga jaspidea (Dumeril, Bibron and Dumeril, 1854) 
from peninsular Thailand. 
photo by P. Chotipan. 

 Jeffrey L. Weinell, Anthony J. Barley, Cameron D. Siler, Nikolai L. Orlov, Natalia B. Ananjeva, Jamie R. Oaks, Frank T. Burbrink and Rafe M. Brown. 2020. Phylogenetic Relationships and Biogeographic Range Evolution in Cat-eyed Snakes, Boiga (Serpentes: Colubridae). Zoological Journal of the Linnean Society. zlaa090. DOI: 10.1093/zoolinnean/zlaa090