Wildlife Strike Risk Assessment at Aerodromes

What Wildlife Strike Risk Assessment Involves

Wildlife strike risk assessment is the structured process of identifying, analysing, and evaluating the likelihood and potential consequences of aircraft collisions with birds, mammals, and other fauna in and around an aerodrome operating environment.

The process typically draws on three categories of input: historical strike data specific to the aerodrome or region, ecological surveys that characterise local species populations and movement patterns, and operational data such as traffic volume, runway orientation, and seasonal scheduling.

The FAA Wildlife Strike Database (https://wildlife.faa.gov/) is one of the most extensive publicly available repositories of reported strike events in civil aviation, covering incidents reported by pilots, airlines, and airports across the United States, and the Transport Canada Wildlife Strike Reporting Program (https://tc.canada.ca/en/aviation/wildlife-strike-reporting) maintains equivalent records for Canadian aerodromes.

Risk assessment outputs are generally expressed as a combination of strike probability and severity potential, often mapped against aircraft categories and operational phases such as approach, landing roll, departure, and climb-out.

Key Hazard Species and Ecological Factors

Not all wildlife presents equivalent risk. Strike severity is influenced by the mass and flocking behaviour of the species involved, the phase of flight at the time of encounter, and the specific aircraft systems affected.

Large soaring birds such as vultures, eagles, and pelicans are associated with higher-severity strikes due to their mass and tendency to occupy climb and approach corridors. Flocking species such as starlings and blackbirds present a different risk profile, with potential for multiple simultaneous ingestion events in turbofan engines.

The Bird Strike Committee USA (https://www.birdstrike.org/) publishes species-specific strike data and guidance documents that aerodrome wildlife managers use to prioritise hazard species identification and habitat modification efforts.

Ecological factors that elevate risk include proximity to wetlands, agricultural land, landfills, and roosting habitat. Seasonal migration corridors can produce transient but significant increases in bird activity that may not be captured in baseline survey data. The Cornell Lab of Ornithology BirdCast (https://birdcast.info/) provides near-real-time migration forecasting that some aerodrome operators reference for short-term hazard awareness. Mammal strikes, while less frequent than bird strikes, carry significant risk on runway surfaces, with deer, coyotes, and rabbits among the most commonly reported mammal species in North American strike records.

Wildlife Hazard Assessments and Management Plans

A Wildlife Hazard Assessment (WHA) is a formal ecological and operational study conducted at an aerodrome to characterise the nature and extent of wildlife hazards. In the United States, the FAA requires a WHA under specific triggering conditions defined in 14 CFR Part 139 (https://www.ecfr.gov/current/title-14/chapter-I/subchapter-G/part-139), including after a damaging strike or when certain wildlife activity thresholds are observed.

A WHA is typically conducted by a qualified wildlife biologist and includes systematic surveys of the aerodrome and surrounding area, species identification, population estimates, and an analysis of attractants. The findings inform a Wildlife Hazard Management Plan (WHMP), which documents the strategies, responsibilities, and procedures the aerodrome will use to reduce strike risk.

In Canada, Transport Canada’s Aerodrome Standards and Recommended Practices (TP 312) (https://tc.canada.ca/en/aviation/publications/aerodrome-standards-recommended-practices-tp-312) address wildlife hazard management as part of broader aerodrome certification requirements.

NorthSky provides operational risk decision support and advisory guidance. Outputs do not constitute regulatory certification, aerodrome licensing, compliance verification, or formal authority determinations.

Habitat Modification and Deterrence Methods

Habitat modification is generally considered the most durable approach to reducing wildlife attractiveness at and around an aerodrome. Common measures include grass height management to reduce foraging suitability for large birds, drainage improvements to eliminate standing water, and removal of seed-bearing vegetation.

The USDA Animal and Plant Health Inspection Service (APHIS) Wildlife Services (https://www.aphis.usda.gov/wildlife-damage/airports) program provides technical assistance to airports in the United States and publishes guidance on habitat management practices specific to aerodrome environments.

Active deterrence methods include pyrotechnics, distress call broadcasts, laser devices, and trained falconry. These methods are most effective when integrated into a broader programme that includes monitoring and adaptive response protocols. Deterrence alone, without habitat modification, tends to produce diminishing returns as wildlife habituates to repeated stimuli.

Lethal control is used in some programmes as a last resort or when specific hazard species cannot be adequately managed through other means. Its use is subject to applicable wildlife protection legislation, including the Migratory Birds Convention Act (https://laws-lois.justice.gc.ca/eng/acts/M-7.01/) in Canada and the Migratory Bird Treaty Act (https://www.fws.gov/law/migratory-bird-treaty-act-1918) in the United States.

Strike Reporting and Data Quality

Accurate and consistent strike reporting is foundational to risk assessment. Underreporting is a well-documented limitation of existing databases. A study published in the Journal of Wildlife Management (https://wildlife.onlinelibrary.wiley.com/journal/19372817) estimated that actual strike rates may be substantially higher than reported figures suggest, particularly for smaller birds and strikes that do not result in visible aircraft damage.

Effective reporting programmes typically include clear internal procedures for crew and ground staff, standardised forms aligned with national database requirements, and periodic review of reported data to identify trends.

Post-strike inspections, including collection and identification of biological remains, improve data quality and support species-specific risk analysis. The Smithsonian Institution Feather Identification Lab (https://www.si.edu/featherid) provides forensic identification services for strike remains submitted by airports and airlines.

Data from strike reports should be reviewed at regular intervals and used to update local risk assessments. A single year of data is generally insufficient to characterise seasonal or multi-year variation in wildlife activity.

Operational Considerations for Safety Personnel

Wildlife risk is not static. It varies by time of day, season, weather conditions, and local land use changes. Safety personnel benefit from maintaining situational awareness of ecological conditions in addition to operational ones.

Communication between wildlife control staff, air traffic services, and flight crews is a practical factor in real-time hazard management. Timely reporting of observed wildlife activity on or near movement areas allows crews to make informed decisions during critical phases of flight.

Some aerodromes integrate wildlife activity data into their safety management system (SMS) processes, treating wildlife strikes as reportable occurrences subject to investigation and corrective action review. The ICAO Safety Management Manual (Doc 9859) (https://www.icao.int/safety/SafetyManagement/Pages/GuidanceDocuments.aspx) provides a framework for integrating hazard identification and risk assessment into aerodrome SMS structures.

Training for aerodrome operations staff on species identification, reporting procedures, and deterrence equipment use is a recurring element in effective wildlife hazard management programmes.