INVASIVE NORTH AMERICAN BEAVER (Castor canadensis): THE DISTRIBUTION OF MITOCHONDRIAL VARIATION ACROSSTHE ARCHIPELAGO OF TIERRA DEL FUEGON

MARIANA FASANELLA, SEBASTIÁN POLJAK AND MARTA S. LIZARRALDE

MASTOZOOLOGí­A NEOTROPICAL

UNIDAD DE ZOOLOGÍA Y ECOLOGÍA ANIMAL, INSTITUTO ARGENTINO DE INVESTIGACIÓN DE LAS ZONAS ARIDAS, CRICYT, CONICET

Lugar: MENDOZA; Año: 2010 vol. 17 p. 43 - 52

0327-9383

ABSTRACT: In 1946 twenty-five pairs of Castor canadensis were introduced into the IslaGrande of Tierra del Fuego (Argentina). Thanks both to environmental conditions favorablefor colonization and an absence of effective control measures, today the estimated abundanceis about 100 000 individuals. We have conducted molecular analysis of beavers fromthree areas of the Archipelago of Tierra del Fuego, in order to characterize the geneticstructure of the invasive population. Our results from AMOVA (Fst= 0.104, p < 0.001)suggest that geographical barriers and large distances could limit gene flow among thepopulations. In the Tierra del Fuego National Park subpopulation, we found a positive andsignificant autocorrelation out to 800 m (r = 0.193, p = 0.003) and the greatest haplotypediversity (= 0.83), which can probably be explained by the control plan used in this areaor by natural selection combined with greater habitat diversity. We propose using theinformation about the demographic spatial dynamics and the spatial genetic structure inthis invasive population to design an effective control strategy.