Wildlife Strike Risk Assessment in Several Italian Airports: Lessons from BRI and a New Methodology Implementation

Abstract

The presence of wildlife in airport areas poses substantial hazards to aviation. Wildlife aircraft collisions (hereafter wildlife strikes) cause losses in terms of human lives and direct monetary losses for the aviation industry. In recent years, wildlife strikes have increased in parallel with air traffic increase and species habituation to anthropic areas. In this paper, we used an ecological approach to wildlife strike risk assessment to eight Italian international airports. The main achievement is a site-specific analysis that avoids flattening wildlife strike events on a large scale while maintaining comparable airport risk assessments. This second version of the Birdstrike Risk Index (BRI2) is a sensitive tool that provides different time scale results allowing appropriate management planning. The methodology applied has been developed in accordance with the Italian Civil Aviation Authority, which recognizes it as a national standard implemented in the advisory circular ENAC APT-01B.

Estimating interspecific economic risk of bird strikes with aircraft

“…However, their use of prior strike data from the same airport and current survey data in the validation brings into question the independence of the validation. Further, we note that the accuracy of the Soldatini et al (, ) metric is dependent upon the quality of the survey data obtained. We therefore questioned whether a basic, species‐specific strike‐risk estimate might be developed that can be used as a foundation for directing management priorities that subsequently could be fine‐tuned via survey data.…”

“…Risk is a unitless metric comprising a conceptual understanding of the sources of the problem (e.g., particular species struck by aircraft, or factors contributing to wildlife hazards to aviation), realistic endpoints or potential events (e.g., a hull loss), mechanisms by which the sources contribute to the defined endpoints (e.g., a focused assessment of risk of engine failure upon ingestion of a bird), and a temporal or spatiotemporal estimate of exposure to the problem sources (Graham et al ). Schafer et al () and Martin et al () advocated for the implementation of a risk assessment that reflects an index of species frequency within critical locations on and near the airport and associated strike‐damage metrics or species‐specific hazard scores (i.e., the likelihood of aircraft damage or effect on flight when strikes occur; DeVault et al ; see also Soldatini et al , ). Blackwell et al () encouraged the development and maintenance of data sets accessible to airport planners and wildlife managers that would allow for a realistic assessment of strike risk relative to current airport conditions, as well as anticipated increases to airport capacity that would require modifications to habitats on and near airports.…”

“…Soldatini et al (, ) developed a risk metric for comparisons among airports, but modified the metric to assess airport‐specific risk in greater detail. Specifically, their metric includes an airport‐specific hazard component for a species–group—the Group Factor—based on mean mass, median flock size recorded on the airport, mean number of strikes per year standardized by total number of aircraft movements per year at the airport, and the highest ranking for species–group effect‐on‐flight for strikes incurred during that year.…”

“…The authors then multiplied the Group Factor by the mean daily number of individuals for the species–group observed on the airport of interest for the specific month, yielding a species–group risk estimate. Notably, the survey component described by Soldatini et al (, ) is intended as a standardized approach that will yield data relative to bird use of different airport land‐cover types, but the metric relies on count data from a single survey point and does not account for biases in species and group abundances estimated during bird surveys (Blackwell et al ).…”

“…In summary, recent risk models either assume a stasis in risk that is reflected by strikes over the previous 5 years (Allan ), focus on across‐airport comparisons of damaging strikes (Dolbeer and Begier ), attempt to quantify airport habitat contributions to strikes involving a species–group (Soldatini et al , ), or subjectively categorize risk (DeFusco et al ). Although these proposed methods have contributed to the discussion on risk estimation techniques for wildlife strikes, only Soldatini et al (, ) have attempted to validate risk estimates. However, their use of prior strike data from the same airport and current survey data in the validation brings into question the independence of the validation.…”