Incipient signs of genetic differentiation among African elephant populations in fragmenting miombo ecosystems in south-western Tanzania

TY - JOUR

T1 - Incipient signs of genetic differentiation among African elephant populations in fragmenting miombo ecosystems in south-western Tanzania

AU - Lobora, Alex L

AU - Nahonyo, Cuthbert L

AU - Munishi, Linus K

AU - Caro, Tim

AU - Foley, Charles

AU - Prunier, Jerome G.

AU - Beale, Colin Michael

AU - Eggert, Lori S.

N1 - © 2018 John Wiley & Sons Ltd. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details.

PY - 2018/12/1

Y1 - 2018/12/1

N2 - Habitat fragmentation can play a major role in the reduction of genetic diversity among wildlife populations. The Ruaha-Rungwa and Katavi-Rukwa ecosystems in south-western Tanzania comprise one of the world’s largest remaining African savannah elephant metapopulation but are increasingly threatened by loss of connectivity and poaching for ivory. To investigate the genetic structure of populations, we compared the genotypes for nine microsatellite loci in the western, central and eastern populations. We found evidence of genetic differentiation among the three populations, but the levels were low and mostly concerned the younger cohort, suggesting recent divergence probably resulting from habitat loss between the two ecosystems. We identified weak isolation by distance, suggesting higher gene flow among individuals located less than 50km apart. In a long-lived species with overlapping generations, it takes a long time to develop genetic substructure even when there are substantial obstacles to migration. Thus, in these recently fragmented populations, inbreeding (and the loss of heterozygosity) may be less of an immediate concern than the loss of adults due to illegal hunting.

AB - Habitat fragmentation can play a major role in the reduction of genetic diversity among wildlife populations. The Ruaha-Rungwa and Katavi-Rukwa ecosystems in south-western Tanzania comprise one of the world’s largest remaining African savannah elephant metapopulation but are increasingly threatened by loss of connectivity and poaching for ivory. To investigate the genetic structure of populations, we compared the genotypes for nine microsatellite loci in the western, central and eastern populations. We found evidence of genetic differentiation among the three populations, but the levels were low and mostly concerned the younger cohort, suggesting recent divergence probably resulting from habitat loss between the two ecosystems. We identified weak isolation by distance, suggesting higher gene flow among individuals located less than 50km apart. In a long-lived species with overlapping generations, it takes a long time to develop genetic substructure even when there are substantial obstacles to migration. Thus, in these recently fragmented populations, inbreeding (and the loss of heterozygosity) may be less of an immediate concern than the loss of adults due to illegal hunting.

U2 - 10.1111/aje.12534

DO - 10.1111/aje.12534

M3 - Article

SN - 0141-6707

VL - 56

SP - 993

EP - 1002

JO - African Journal of Ecology

JF - African Journal of Ecology

IS - 4

ER -