Systematics of isolated populations of short-tailed shrews (Soricidae: Blarina) in Texas

Abstract

Two isolated and taxonomically unassigned populations of short-tailed shrews (Blarina) exist in Texas, 1 in the Lost Pines region including Bastrop County and 1 at Aransas National Wildlife Refuge on the Gulf Coast. Molecular and morphological methods were used to determine the systematic status of the 2 disjunct Texas populations. Multivariate analyses of size-influenced cranial measurements were unsuccessful in identifying specimens from these populations at the species level. Phylogenetic analyses of the mitochondrial cytochrome-b gene revealed that the samples from disjunct Texas populations form a monophyletic sister clade to B. hylophaga from Kansas and Nebraska; there is little divergence between the 2 Texas populations. Genetic divergence between Texas and Kansas-Nebraska B. hylophaga is comparable to taxonomically recognized east-west divisions within B. brevicauda and B. carolinensis. Therefore, the name Blarina hylophaga plumbea, which originally was applied to the Aransas County population, also should include the Bastrop County population. © 2005 American Society of Mammalogists.