Abstract
► We detect 17 hybrids with ancestry in the extinct Galápagos tortoise C. abingdoni. ► Our results suggest many F1 and possibly purebred C. abingdoni live on Volcano Wolf. ► We show these individuals are spatially concentrated on western Volcano Wolf. ► These individuals are valuable for repatriation of C. abingdoni to Pinta Island.
The death of Lonesome George, the last known purebred individual of Chelonoidis abingdoni native to Pinta Island, marked the extinction of one of 10 surviving giant tortoise species from the Galápagos Archipelago. Using a DNA reference dataset including historical C. abingdoni and >1600 living Volcano Wolf tortoise samples, a site on Isabela Island known to harbor hybrid tortoises, we discovered 17 individuals with ancestry in C. abingdoni. These animals belong to various hybrid categories, including possible first generation hybrids, and represent multiple, unrelated individuals. Their ages and relative abundance suggest that additional hybrids and conceivably purebred C. abingdoni individuals still occur on Volcano Wolf. Spatial analyses suggest locations where additional individuals with C. abingdoni ancestry are most likely to be recovered, consistent with historical records of human movement of tortoises. These results provide an opportunity for species recovery of Pinta Island tortoises using individuals with C. abingdoni ancestry.