A comparison of taxonomic distinctness versus richness as criteria for setting conservation priorities for North American birds

In choosing sites for a conservation reserve network, representation of the greatest number of species in the sites selected is a common objective. Th is approach implicitly assumes that all species have equal conservation val ue. An alternative objective is to represent the greatest genetic diversity in selected sites. This approach gives greater weight to species that are more genetically distinct. Such species tend to contain more unique genetic material, which would be lost if such species became extinct. In this pape r, we calculate a diversity measure for a given set of species based on the branch length of the phylogenetic tree for the set. We use genetic distanc es between bird species in 147 genera based on the results of DNA hybridiza tion research. Distribution information for bird species in the US comes fr om the Breeding Bird Survey. We compare resulting conservation reserve netw orks when the objective is the number of genera represented versus the dive rsity of genera represented. We find that the different objectives produce notably similar results. (C) 2000 Elsevier Science Ltd. All rights reserved .