V. Georgalas

An ecological approach to birdstrike risk analysis

Airports are peculiar developed habitats that, besides being extremely noisy and unappealing to some bird species, are highly attractive to others. Bird–aircraft collisions, or birdstrikes, cause losses in terms of human lives, direct monetary losses and associated costs for the civil aviation industry. In recent years, birdstrike risk assessment studies have focused on the economical aspects of the damage caused by wild animals and the hazards of wildlife–aircraft collisions, while an ecological approach, taking into account animal behaviour for the analysis of such events, has seldom been adopted. We conducted a risk analysis for birdstrikes at the Venice Marco Polo International Airport (VCE), Italy. We defined the key variables involved in these events and summarised their interactions in a single metric risk index we called the “Birdstrike Risk Index” (BRI). Our aim was to provide a tool for birdstrike risk analysis that described the risk on the basis of the actual presence of birds at airports. The application of the BRI at VCE allows relative risks across species to be defined, providing information for prioritising management actions. Furthermore, due to the seasonality of bird species presences, the application of the BRI to a long-term data series should give clues of birdstrike risk in future scenarios. This new ecological approach that we applied to a particular airport could easily be adapted for use at other airports worldwide and integrated into risk assessment procedures. The study results and the BRI tool are addressed to scientific consultants of airport safety managers.

Relationships between relative size of sexual traits and male mating success in the Mediterranean killifish Aphanius fasciatus (Nardo, 1827)

Some relationships between the relative size of secondary sexual traits and male mating success were investigated in the killifish Aphanius fasciatus (Nardo, 1827). The relative ability of a male to compete with another male for access to a ripe female was related to the relative size of male sexual traits by means of a behavioural experiment under controlled laboratory conditions. Furthermore, the covariation in the expression of sexual traits was analysed from a sample of field-collected males. Results of the behavioural experiment showed that male dominance and success were positively related to the relative height of the dorsal fin, but not to the pattern of vertical bars along body sides. Within the analysed male population, males with larger fins tended to have thinner bars, whereas there was no statistically significant correlation with bar number or with bar asymmetry. The results were discussed in terms of advantages conferred by larger dorsal fins in killifish breeding systems, and developmental constraints defining a multiple set of traits correlated to male quality were also hypothesised.

The reproductive behavior of Economidichthys pygmaeus: secondary loss of sound production within the sand goby group?

In this study, the reproductive behavior of Economidichthys pygmaeus was investigated under laboratory conditions with simultaneous video and acoustic recordings. Males of the freshwater goby E. pygmaeus do not produce sounds either during the courtship/spawning phase or during aggressive interactions. A detailed analysis of the behavioral sequences revealed the absence of any digging and nest-building activities, whereas the other behavioral components of courtship and spawning are similar to those described for other goby species, showing also a similar function. Results were discussed in terms of secondary loss of sound production within the sand gobies, a group of highly soniferous fishes in the family Gobiidae.

Wildlife strike risk assessment in several Italian airports: lessons from BRI and a new methodology implementation

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.