Dublin Hareport: The movement ecology and airfield interactions of resident, airside hares, at an international airport.

Abstract

Understanding how animals move and use space within an environment is vital for the development and implementation of effective management actions. Within airfield environments, animal movement can present a substantial risk to aircraft, resulting in wildlife-aircraft collisions (strikes) if animals enter into the manoeuvring areas of the airfield, namely the runways, taxiways and areas that connect the two (hereafter collectively referred to as 'tarmacked areas'). However, reliable ecological data to inform management decisions can be difficult to obtain in such environments, due to access restrictions. Here, we present the first GPS data describing the movement ecology and spatial use of mammals on an airfield - Irish hare (Lepus timidus hibernicus), at Dublin International Airport - through the deployment of five GPS collars. A total of 4571 tarmacked area interactions were recorded between December 2021 and August 2022, with all five hares engaging with tarmacked areas. Between December and August, the highest number of interactions were recorded for the month of April (n = 1073), followed by March (n = 703). There was a mean of 4.3 (range: 0-65) interactions with tarmacked areas, per hare, per day throughout the study period. Hares most frequently engaged with tarmacked areas between 05:00 and 07:59, with some seasonal variation. The greatest cumulative distance moved per month was observed in May (505 km) and April (503 km). We identified that the average home range size of collared hares was 2.8 km2 (±SD 0.1 km2), based on 95% Kernel Utilisation Distribution. Furthermore, we demonstrate that the hares incorporate tarmacked area habitat types into their home ranges with up to 13% of one individual's movements incorporating these areas. Our study demonstrates the suitability of GPS tracking devices for studying the movement ecology of high-risk mammal species at airfields in order to inform airside management practices.