title: Genetic connectivity across marginal habitats: the elephants of the Namib Desert.
abstract: Locally isolated populations in marginal habitats may be genetically distinctive and of heightened conservation concern. Elephants inhabiting the Namib Desert have been reported to show distinctive behavioral and phenotypic adaptations in that severely arid environment. The genetic distinctiveness of Namibian desert elephants relative to other African savanna elephant (Loxodonta africana) populations has not been established. To investigate the genetic structure of elephants in Namibia, we determined the mitochondrial (mt) DNA control region sequences and genotyped 17 microsatellite loci in desert elephants (n = 8) from the Hoanib River catchment and the Hoarusib River catchment. We compared these to the genotypes of elephants (n = 77) from other localities in Namibia. The mtDNA haplotype sequences and frequencies among desert elephants were similar to those of elephants in Etosha National Park, the Huab River catchment, the Ugab River catchment, and central Kunene, although the geographically distant Caprivi Strip had different mtDNA haplotypes. Likewise, analysis of the microsatellite genotypes of desert-dwelling elephants revealed that they were not genetically distinctive from Etosha elephants, and there was no evidence for isolation by distance across the Etosha region. These results, and a review of the historical record, suggest that a high learning capacity and long-distance migrations allowed Namibian elephants to regularly shift their ranges to survive in the face of high variability in climate and in hunting pressure.
authors.affiliation: Department of Animal Sciences University of Illinois at Urbana-Champaign Urbana Illinois 61801.
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Ishida
authors.affiliation: Department of Biology Queen's University Kingston ON K7L 3N6 Canada.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Van Coeverden de Groot
authors.affiliation: Namibian Elephant and Giraffe Trust Outjo Namibia; Present address: Fowlers Gap Arid Zone Research Station School of Biological, Earth and Environmental Sciences University of New South Wales Kensington NSW 2051 Australia.
authors.forename: Keith E A
authors.initials: KE
authors.lastname: Leggett
authors.affiliation: Department of Life Sciences San Diego Zoo Global San Diego California 92112.
authors.forename: Andrea S
authors.initials: AS
authors.lastname: Putnam
authors.affiliation: Elephant Human Relations Aid (EHRA) Swakopmund Namibia.
authors.forename: Virginia E
authors.initials: VE
authors.lastname: Fox
authors.affiliation: Department of Biology Queen's University Kingston ON K7L 3N6 Canada.
authors.forename: Jesse
authors.initials: J
authors.lastname: Lai
authors.affiliation: Department of Biology Queen's University Kingston ON K7L 3N6 Canada.
authors.forename: Peter T
authors.initials: PT
authors.lastname: Boag
authors.affiliation: Puget Sound Institute University of Washington Tacoma Washington 98421.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Georgiadis
authors.affiliation: Department of Animal Sciences University of Illinois at Urbana-Champaign Urbana Illinois 61801; Carl R. Woese Institute for Genomic Biology University of Illinois at Urbana-Champaign Urbana Illinois 61801.
authors.forename: Alfred L
authors.initials: AL
authors.lastname: Roca
keywords: Etosha National Park; Loxodonta africana zukowski; microsatellites; mitochondrial DNA