Dunnarts from Boullanger Island: new evidence and reassessment of a taxonomic issue with resource implications.

Abstract

Crowther et al. (1999) described an island population of an Australian dasyurid marsupial, Sminthopsis griseoventer, as a new subspecies on molecular (allozyme) and morphological grounds despite a previously published, contradictory genetic study and evidence of sympatry with its mainland conspecific. The legitimacy of this taxonomic arrangement has implications for the allocation of scarce management resources because the new taxon could be considered 'Critically Endangered'. Samples of the original tissues from which the molecular data cited by Crowther et al. were obtained no longer exist. Therefore, salient components of that work were rerun with fresh tissue and the results used to reassess evidence that the island population warrants recognition as a subspecies. We conclude that neither the molecular nor the morphological data supports differentiation at taxonomic or evolutionarily significant levels. Nevertheless, there is a good case for recognising the island population as an important management unit. This case study emphasises the importance of sound taxonomy determined by macro and molecular characters as a prerequisite to allocating resources for conservation.