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

et al. (2011) Wildlife Strike Risk Assessment in Several Italian Airports: Lessons from BRI and a New Methodology Implementation. PLoS ONE 6(12): e28920. doi:10.1371/journal.pone.0028920 Wildlife Strike Risk Assessment in Several Italian Airports: Lessons from BRI and a New Methodology Implementation Cecilia Soldatini 0 Yuri Vladimir Albores-Barajas 0 Tomas Lovato 0 Adriano Andreon 0 Patrizia Torricelli 0 Alessandro Montemaggiori 0 Cosimo Corsa 0 Vyron Georgalas 0 Brock Fenton, University of Western Ontario, Canada 0 1 Department of Environmental Sciences , Informatics and Statistics , University Ca'Foscari of Venice , Venice , Italy , 2 Aeroporto di Venezia Marco Polo S.p.A. SAVE , Venice , Italy , 3 Stazione Romana Osservazione e Protezione Uccelli , Rome, Italy, 4 ENAC - Ente Nazionale Aviazione Civile, Rome , Italy , 5 CMCC - Centro Euro-Mediterraneo per i Cambiamenti Climatici , Bologna , Italy 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 APT01B. - Wildlife, particularly birds, is increasingly present in humanmodified habitats due to an increase of synanthropic species populations and to the process of habituation to anthropogenic resources that many species are undergoing [1,2]. Many of these species present life histories that promote adaptation to urban environmental characteristics [3,4,5]. This factor, together with the increase of air traffic [6], has resulted in a worldwide increase in the number of wildlife strikes [6,7]. To our knowledge, in peer reviewed ISI journals there are only four methods to perform a bird strike risk assessment [8,9,10,11]. A more effective approach to the growing wildlife hazards for the air safety should involve an ecological based tool capable to deal with the species-specific characteristics present in airports, where 96% of the wildlife strikes occur [6]. There are two main components of a wildlife strike event: aircraft and wildlife. From the aircraft perspective, there is not much that can be done to avoid strikes because aircraft have a set route and speed for takeoff and landing and any change to these parameters may create more danger than reducing it. Nowadays, aircraft characteristics are fairly homogeneous on a geographical scale, while from the wildlife perspective, there is a much larger variability, both seasonal and geographical. For instance, some species are gregarious off the breeding period but become solitary/ coupled during the breeding period. Generally, during the migration period, there is a higher richness and abundance along the migratory routes. Besides, after the breeding season, the inexperienced juveniles involved in collisions with aircraft may contribute significantly to the increase of wildlife strikes [12]. The high variability of biogeographic gradients poses a serious problem to wildlife strike risk assessment, as it is reflected in wildlife community composition. This means that airports present in the same geographical area may have differences in wildlife community composition due to differences in the environmental characteristics present in the immediate vicinity and, thus, different risks for wildlife strikes. Habituation to anthropic environments is a process sensitive to cultural dynamics [3,13], therefore the same species may be at different stages of the process in different geographical areas [2,14]. Human activities in the surrounding areas of airports are also crucial in determining the wildlife strike risk because they may attract numerous species that are hazardous for air navigation [15]. The Italian Civil Aviation Authority (hereafter ENAC) requires the environmental monitoring of an airports surrounding area within a 13 km radius from the airport [16]. Furthermore, in Italy, the airport management authority is responsible for collecting and submitting data to ENAC of all wildlife strikes occurring within the airports perimeter and up to a height of 300 ft [17]. Among the several methods to estimate wildlife strike hazard proposed [8,9,10,11], some use an economic perspective [8,11], while others use data collected on a national level [9]. The major problem with these approaches is that they may not reflect the characteristics of each individual airport, making comparisons between airports difficult. To render things even more complicated it often happens that the wildlife strike data available are incomplete because records from pilots may lack species information or carcasses may be lost [18]. Thus, there is a general need for a standardized method that is easy to apply and statistically robust. Considering the differences in monitoring programs between airports, the risk assessment tool should work with different time series of data. On a previous version of the Birdstrike Risk Index BRI [10], we proposed a method that takes into account the ecological characteristics of the bird communities resident in the airport area. In the first version of the index, the novel approach allowed to correlate some of the variables involved in the birdstrike, but since more data became available and airports inter-comparisons were recursively required, the need of an Index improvement appeared necessary. In this paper, we propose a modified version of the Birdstrike Risk Index, BRI [10], here named BRI2, with the aim of introducing a more general applicability by improving the species categorization and testing the robustness of the group risk factor. A formal revision of the index structure was also carried out in order to enable the comparison of results among different airports. An increasing trend in the number of flights per year (Table 1) was observed in the major part of the investigated airports for the period 20062010, contrarily to the high variability of wildlife strike tendency that appears to be largely influenced by sitespecific conditions. The linear regression analysis between airport traffic and wildlife strikes resulted to be significant only for airport D, with a correlation coefficient equal to 0.89. The results obtained fr (...truncated)