Genetic and archaeological evidence for a former breeding population of Aleutian Cackling Goose (Branta hutchinsii leucopareia) on Adak Island, central Aleutians, Alaska

Abstract

Many well-preserved bones of medium-sized goose have been recovered from the Zeto Point archaeological site (ADK-011) on Adak Island in the central Aleutians, Alaska, that date to ca. 170–415 years before present based on conventional radiometric dates of the deposits. This prehistoric sample includes remains of adults and unfledged goslings that defied confident identification based on osteological criteria. While the presence of newborns indicates that Adak was a breeding ground, which species was doing the nesting remained uncertain. Of the five species of medium-sized goose (order Anseriformes, family Anatidae) known or presumed to visit Adak Island, three are rarely sighted. The only common visitor is the Emperor Goose ( Chen canagica (Sevastianov, 1802)). The Aleutian Cackling Goose ( Branta hutchinsii leucopareia (Brandt, 1836)) breeds elsewhere in the Aleutians but does not currently breed on Adak Island and there are no records of it nesting there in the past. Here DNA sequences from portions of the cytochrome b (cytb) gene and the control region (CR) of the mitochondrial genome were recovered from 28 of 29 Adak prehistoric goose remains. All adult specimens identified to species were either C. canagica or B. h. leuopareia, but all specifically identified juvenile specimens were B. h. leuopareia. The results demonstrate that Adak Island was a breeding ground of the Aleutian Cackling Goose prior to European contact.