title: Integrating archaeology and ancient DNA analysis to address invasive species colonization in the Gulf of Alaska.
abstract: The intentional and unintentional movement of plants and animals by humans has transformed ecosystems and landscapes globally. Assessing when and how a species was introduced are central to managing these transformed landscapes, particularly in island environments. In the Gulf of Alaska, there is considerable interest in the history of mammal introductions and rehabilitating Gulf of Alaska island environments by eradicating mammals classified as invasive species. The Arctic ground squirrel (Urocitellus parryii) is of concern because it affects vegetation and seabirds on Gulf of Alaska islands. This animal is assumed to have been introduced by historic settlers; however, ground squirrel remains in the prehistoric archaeological record of Chirikof Island, Alaska, challenge this timeline and suggest they colonized the islands long ago. We used 3 lines of evidence to address this problem: direct radiocarbon dating of archaeological squirrel remains; evidence of prehistoric human use of squirrels; and ancient DNA analysis of dated squirrel remains. Chirikof squirrels dated to at least 2000 years ago, and cut marks on squirrel bones suggested prehistoric use by people. Ancient squirrels also shared a mitochondrial haplotype with modern Chirikof squirrels. These results suggest that squirrels have been on Chirikof longer than previously assumed and that the current population of squirrels is closely related to the ancient population. Thus, it appears ground squirrels are not a recent, human-mediated introduction and may have colonized the island via a natural dispersal event or an ancient human translocation.
authors.affiliation: Department of Archaeology, Boston University, 675 Commonwealth Avenue, Boston, MA, 02215, U.S.A.
authors.forename: Catherine
authors.initials: C
authors.lastname: West
authors.affiliation: Department of Anthropology, University of Oklahoma, Norman, OK, 73019, U.S.A.|Center for Conservation Genomics, Smithsonian Conservation Biology Institute, National Zoological Park, P.O. Box 37012, MRC 5513, Washington, D.C., 20013-7012, U.S.A.
authors.forename: Courtney A
authors.initials: CA
authors.lastname: Hofman
authors.affiliation: Alaska Maritime National Wildlife Refuge, U.S. Fish and Wildlife Service, 95 Sterling Hwy #1, Homer, AK, 99603, U.S.A.
authors.forename: Steve
authors.initials: S
authors.lastname: Ebbert
authors.affiliation: Alaska Region, U.S. Fish and Wildlife Service, 1011 East Tudor Road, MS 211, Anchorage, AK, 99503, U.S.A.
authors.forename: John
authors.initials: J
authors.lastname: Martin
authors.affiliation: Center for Conservation Genomics, Smithsonian Conservation Biology Institute, National Zoological Park, P.O. Box 37012, MRC 5513, Washington, D.C., 20013-7012, U.S.A.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Shirazi
authors.affiliation: Department of Anthropology, University of Alaska Anchorage, 3211 Providence Drive, Anchorage, AK, 99508, U.S.A.
authors.forename: Samantha
authors.initials: S
authors.lastname: Dunning
authors.affiliation: Center for Conservation Genomics, Smithsonian Conservation Biology Institute, National Zoological Park, P.O. Box 37012, MRC 5513, Washington, D.C., 20013-7012, U.S.A.
authors.forename: Jesus E
authors.initials: JE
authors.lastname: Maldonado
mesh_terms: D000413:Alaska; D000818:Animals; D001106:Archaeology; D003247:Conservation of Natural Resources; D000072441:DNA, Ancient; D006801:Humans; D058865:Introduced Species; D062312:Islands; D012589:Sciuridae
chemical_list: D000072441:DNA, Ancient
keywords: Urocitellus parryii; ancient translocation; ardilla terrestre; ground squirrel; invasive species management; manejo de especies invasoras; translocación antigua; zooarchaeology; zooarqueología