Hares in the long grass: increased aircraft related mortality of the Irish hare (Lepus timidus hibernicus) over a 30-year period at Ireland’s largest civil airport

Abstract

Collisions between wildlife and aircraft are a serious and growing threat to aviation safety. Understanding the frequency of these collisions, the identity of species involved, and the potential damage that can be inflicted on to aircraft aid mitigation efforts by airfield managers. A record of all animal carcasses recovered from Dublin International Airport, Ireland’s largest civil aviation airport, has been maintained since 1990 where strikes with the endemic Irish hare (Lepus timidus hibernicus), a protected subspecies of mountain hare, are of particular concern despite substantial management efforts from the airfield authority. The first strike event with a hare was recorded in 1997, and strike events have substantially increased since then, with a sharp increase recorded in 2011. Over a 30-year period, a total of 320 strike events with the Irish hare have been recorded at the airfield. To date, no strike event with a hare has resulted in damage to an aircraft. However, carcasses can present as a major attraction to avian scavenger species in addition to posing as a risk of causing foreign object damage in the event of an undetected carcass. Hare strikes are discussed in the context of the rate of civil aircraft movements, possible direct and indirect damage to aircraft, and airfield wildlife hazard management. Here, we demonstrate that not only are strike events increasing by 14% on an annual basis, but that the kinetic energy of such an event has the potential to cause significant damage to an aircraft.

Hareport hazard: Identifying hare activity patterns and increased mammal–aircraft strike risk at an International Airport

“…Despite the presence of other mammal species occasionally reported at the airfield including foxes ( Vulpes vulpes ), hedgehogs ( Erinaceus europaeus ), rabbits ( Oryctolagus cuniculus ), rats ( Rattus norvegicus ), domestic cats ( Felis catus ) and bats (Kelly et al., 2017), strike events with these species are rare (Bolger & Kelly, 2008). With an increasing number of hare strike events reported annually and a sufficient kinetic energy to cause damage to an aircraft (Ball, Butler, et al., 2021a), the Irish hare is the most hazardous mammal species at the airfield. Therefore, here we focus on the Irish hare due to a high incidence of strike events.…”

“…runways, taxiways) following a reported strike event or during mandatory routine inspections with the location and environmental conditions surrounding an event recorded (e.g. weather; see Ball, Butler, et al, 2021a). From 2012 onwards, temporal data detailing the date and time of a strike were also recorded, resulting in n = 238 hare strike events with an associated strike time from 2012 until December 2021.…”

“…Lagomorphs (particularly rabbits and hares) are frequently reported in airfield environments and are reportedly involved in strike events near globally (Ball, Caravaggi, & Butler, 2021b; Dolbeer & Begier, 2021; Kitowski, 2016). A population of the Irish hare ( Lepus timidus hibernicus , Bell 1837), an endemic subspecies of the Mountain hare ( L. timidus , Linnaeus 1758), resides at Dublin Airport in the Republic of Ireland where strike events between hares and aircraft have been increasing by an average of 14% annually since 1997 (Ball, Butler, et al., 2021a). The damage potential of a hare strike (10,576 J; Ball, Butler, et al., 2021a), in tandem with the conservation status (Caravaggi et al., 2017; Reid et al., 2010) of this endemic subspecies, require that effective management strategies be developed to mitigate against strike events.…”

“…A population of the Irish hare ( Lepus timidus hibernicus , Bell 1837), an endemic subspecies of the Mountain hare ( L. timidus , Linnaeus 1758), resides at Dublin Airport in the Republic of Ireland where strike events between hares and aircraft have been increasing by an average of 14% annually since 1997 (Ball, Butler, et al., 2021a). The damage potential of a hare strike (10,576 J; Ball, Butler, et al., 2021a), in tandem with the conservation status (Caravaggi et al., 2017; Reid et al., 2010) of this endemic subspecies, require that effective management strategies be developed to mitigate against strike events. Here, we investigate whether motion‐activated camera traps – an easily accessible and relatively inexpensive method of monitoring – can be successfully used to identify periods of increased strike risk between aircraft and hares.…”

Oliver Tambo International Airport, South Africa: Land-Use Conflicts Between Airports and Wildlife Habitats

“…As airport buffer zones attract birds and other wildlife, airport operators must manage bird strike hazards (Ball et al, 2021;Carswell et al, 2021). They do this by deploying three main strategies: (1) directing bird behavior; (2) modifying habitats, and (3) adjusting cockpit actions for landings and take-offs (Dolbeer, 2011;Metz et al, 2021).…”