The wildlife strikes back: determining the secondary strike risk associated with a mammal–aircraft collision

Wildlife–aircraft collisions are becoming increasingly common and pose a serious threat to the global aviation industry. While wildlife strike mitigation is a well-researched area, often focusing on a specific species or taxonomic group, secondary strike risk with scavenger or predatory species is rarely considered within the literature. Dublin Airport is the largest civil airport in the Republic of Ireland, reporting an average of 23.9 (±12.8 SD) strikes with native Irish hares (Lepus timidus hibernicus) annually. We employed motion-activated camera traps to identify the species attracted to simulated hare-strike events and to record the time to initial carcass detection. We used commercially available rat carcasses as a proxy for hare carcasses to assess the secondary strike risk associated with such events. We recorded 542 detections within 24 hours of carcass deployment from 82 trials. Hooded crows (Corvus cornix) were the most frequently detected species, involved in 86% of interactions. Initial carcass detection took an average of 4 hours and 54 minutes for avian species, with birds spending an average of 5 minutes and 29 seconds with a carcass. In comparison, it took mammal species an average of 9 hours and 32 minutes to detect the carcass in the first instance. Mammals remained with the carcass for an average of 2 minutes and 35 seconds. These data indicate that current clean-up practices at Dublin Airport (i.e., immediate clean-up and closing of the runway to facilitate clean-up operations) are adequate for reducing the likelihood of a secondary strike event.