ND2 as an Additional Genetic Marker to Improve Identification of Diving Ducks Involved in Bird Strikes

Knowing the exact species of birds involved in damaging collisions with aircraft (bird strikes) is paramount to managing and preventing these types of human–wildlife conflicts. While a standard genetic marker, or DNA barcode (mitochondrial DNA gene cytochrome-c oxidase 1, or CO1), can reliably identify most avian species, this marker cannot distinguish among some closely related species. Diving ducks within the genus Aythya are an example of congeneric waterfowl involved in bird strikes where several species pairs cannot be reliably identified with the standard DNA barcode. Here, we describe methods for using an additional genetic marker (mitochondrial DNA gene NADH dehydrogenase subunit 2, or ND2) for identification of 9 Aythya spp. Gene-specific phylogenetic trees and genetic distances among taxa reveal that ND2 is more effective than CO1 at genetic identification of diving ducks studied here. Compared with CO1, the ND2 gene tree is more statistically robust, has a minimum of 1.5 times greater genetic distance between sister clades, and resolves paraphyly in 2 clades. While CO1 is effective for identification of most bird strike cases, this study underscores the value of targeted incorporation of additional genetic markers for species identification of taxa that are known to be problematic using standard DNA barcoding.