Independent lines of evidence document the identification of bird–aircraft collision sample of Western Marsh Harrier (<i>Circus aeruginosus</i>) in continental USA

Abstract

Bird–aircraft collisions (birdstrikes) occur daily and are global in scale. In the USA, the Federal Aviation Administration (FAA) tracks information regarding birdstrikes in the National Wildlife Strike Database to improve aviation safety. Here, we describe the use of independent lines of evidence for final species identification of an unusual birdstrike sample submitted for identification from Newark Liberty International Airport, New Jersey, in November 2022. Using DNA barcoding, molecular sexing, feather pattern matching, feather ultrastructure, and online community science reports, we surmise that the birdstrike sample originated from the same individual Western Marsh Harrier (Circus aeruginosus) that was photographed and reported to eBird at a location proximate to where the birdstrike occurred. The identification of this sample suggests an unusual end to a rare bird in the USA with the feather sample representing the first specimen record (USNM 665437) of Western Marsh Harrier in the continental United States. This case study underscores the importance of linking independent lines of evidence to confirm complex bird identifications, help document bird records, and track unusual bird movements.