Bird Strike Committee Proceedings


Date of this Version

September 2007


The U.S. Air Force (USAF) and the Federal Aviation Administration (FAA) have been supporting a free-of-charge birdstrike identification program at the Smithsonian Institution for many years. Approximately 50% of the birdstrike cases received are identified to species level using whole feathers, or feather fragments in comparison with museum specimens. The remaining cases are identified using microscopic analysis and/or DNA “barcoding”. DNA barcoding is the newest tool in the birdstrike identification toolbox and involves extracting mtDNA (cytochrome c oxides subunit 1, COI, cox1, “barcode gene”) from birdstrike samples that consist of blood and tissue and then matching the unknown sequence to a DNA library available on the Barcode of Life Database (BoLD). We analyzed birdstrike remains during Fall migration 2006 (1 September – 31 December) to evaluate current collecting methods for minute birdstrike evidence, and to analyze the condition of the samples submitted for DNA testing. Although the age of the sample (time from birdstrike event to time of identification) was not a factor in DNA extraction success, the condition of the sample received in the lab was critical. More than 77% of the cases that contained moldy paper towel samples did not yield viable DNA. The poor condition of these samples leads us to recommend modifications to current field collecting techniques for all birdstrike evidence consisting of blood and/or tissue. New field collecting recommendations include: 1) using alcohol (ethanol or isopropyl) or alcohol-based toweletts, instead of water and paper towels, to wipe the aircraft of bird evidence, or 2) use a DNA ‘fixing’ card such as the Whatman FTA® card to prevent DNA degradation as soon as possible. These methods will help preserve the DNA, prevent mold growth, and increase the ability to extract viable DNA from blood and tissue samples.