Environmental DNA from lake water is effective at detecting elusive
geese and other waterfowl species
Abstract
For many aquatic and semiaquatic mammal, amphibian and fish species,
environmental DNA (eDNA) methods are employed to detect species
distribution and to monitor their presence, but eDNA is much less
employed for avian species. Here, we developed primers for the detection
of true geese and swan species using eDNA and optimized a PCR protocol
for eDNA. We selected taiga bean goose (Anser fabalis fabalis) as
our focal (sub)species and sampled water from lakes, from which the
presence of taiga bean goose was visually confirmed. We filtered the
lake water and extracted eDNA. We also included field negative controls
(sterile water) which were handled similarly as eDNA samples to control
sterility of equipment. For testing if taiga bean goose DNA could be
detected among DNA of other goose species, we similarly sampled eDNA
from a zoo pond housing several Anatidae species. We were able to detect
taiga bean goose DNA in all but one of the tested lakes, including the
zoo pond. The primers developed are not species-specific, but rather
specific for the genus Anser, due to close relatedness of Anser
species. We also developed eDNA primers for Branta-species and
Cygnus-species and tested these primers using the same samples.
Canada goose (B. canadensis) and barnacle goose (B.
leucopsis) DNA were only detected in the zoo pond (in which they were
present), as the sampled natural lakes fall outside the range of these
species. We detected whooper swan (C. cygnus) DNA in three lakes
and the zoo pond (in which the species was present). The eDNA method
presented here provides a potential means to monitor elusive goose
species and to study the co-occurrence of large waterfowl.