Sampling of environmental DNA for breeding distribution mapping in an endangered goose species, the lesser white-fronted goose

Abstract

AbstractDetecting extremely rare and elusive species from vast wilderness areas is highly challenging. The Fennoscandian population of lesser white-fronted goose (LWfG;Anser erythropus) is the most endangered bird in Europe, with only 25–30 breeding pairs remaining in Northern Norway. Its former breeding range, however, covered mountainous parts of the entire Fennoscandia. Targeted conservation efforts during the 21st century has enabled the LWfG to recolonise some of its former breeding areas in Norway and possibly also in Finland. To locate individuals of this elusive species during the breeding season, we used environmental DNA (eDNA) extracted from filtered lake water from selected lakes in the former breeding habitat in northern Finland. We amplified and sequenced a short region of the mitochondrial control region to identifyAnser-goose species in the lake water. In addition, we sampled eDNA from the water of a spring staging site of the Fennoscandian LWfG and from a known Norwegian breeding site, from which eDNA of the LWfG was positively found. eDNA of the LWfG was not detected within the former Finnish breeding range. Based on this, the LWfG has not recolonised its former breeding habitats in Finland or alternatively, we may not have sampled the exactly right lakes, or the eDNA concentration was below detection limits. Due to genus-specific primers, we discovered taiga (A. fabalis fabalis) and tundra bean goose (A. fabalis rossicus) eDNA from several lakes in Northern Finland, proving the usefulness of the method.