When animals and aircraft occupy the same airspace at the same time, accidents happen. Birds are the animal most commonly involved in animal-aircraft collisions, according to the Federal Aviation Administration (FAA) website’s section about wildlife management, accounting for approximately 97% of wildlife strikes annually. Mammals and reptiles (particularly white-tailed deer, coyotes and alligators) collectively make up the remaining 3% of annual wildlife strikes.
The Wildlife Services division of the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) states in its “Strike One — You’re Out!” publication that conservative estimates place the annual cost of wildlife strikes in the U.S. at more than $625 million and 600,000 hours of lost time. The publication adds that the actual figures are likely much higher, because it is estimated that only about one in five wildlife strikes are properly documented and reported to the FAA.
In spite of the obvious financial and safety incentives, effective wildlife management remains a challenging task. Increasing human and wildlife populations lead to competition for space. The populations of many species that are often implicated in wildlife strikes have risen dramatically in recent decades, as detailed in the APHIS Fiscal Year 2019 report, “Protecting the Flying Public and Minimizing Economic Losses Within the Aviation Industry.” For example, the Canada goose, whose large size and flocking tendency makes it especially hazardous to aircraft, has an estimated population of more than 5 million in North America, according to BirdLife International’s Data Zone profile of the Canada goose Branta canadensis. Unfortunately, Canada geese and other hazardous wildlife rapidly grow accustomed to various wildlife management techniques and deterrent methods.
Still, through persistent preventative measures and ongoing management, wildlife hazards at airports can be minimized. It is sometimes said that airports need to treat wildlife like relatives who have overstayed their welcome — never let them get comfortable! Airports can discourage animals from using airfields by eliminating or limiting attractants, such as food plants, open water and cover in the form of trees or brush. Selective breeding can produce plant varieties known as “fescue cultivars,” which frustrate wildlife. Tall fescue cultivars contain symbiotic fungi that produce alkaloids, bitter-tasting compounds that deter grass-eating animals and inhibit digestion when consumed. Tall fescues can thrive in airport environments, even with heavy mowing. FAA guidance suggests that stormwater detention basins should be modified to allow for complete drainage within 48 hours, when possible. For detention ponds that cannot be drained completely, the FAA’s advisory circular of Feb. 21, 2020, encourages the use of physical barriers, such as floating covers, netting or wire grids, after eliminating emergent and submergent vegetation that can be used as sources of cover and food.
To protect the public, airports need a comprehensive wildlife hazard management plan (WHMP). The FAA provides general guidance, but the first step is always a risk assessment, or wildlife hazard assessment (WHA), to determine specifics. Depending on the location of the airport, the WHA will provide baseline data from which to prepare an effective WHMP. While many tools are available, not all airports need the same plan. A large airport with a high volume of operations involving large, turbine-powered passenger aircraft should have a complete wildlife control program. On the other hand, a small airport that deals mostly with light, piston-powered, fixed-wing aircraft may manage with a communications and warning procedure to advise pilots of unusual wildlife activity, according to the FAA Wildlife Hazard Mitigation Program fact sheet released Dec. 17, 2020.
Successful wildlife management requires a data-based foundation formulated from an on-site assessment of the particular airport. Once the WHMP is completed, long-term success will always depend on continued leadership support, flexibility and persistence.
Hanson has the staff and knowledge to help with wildlife mitigation at your airport. For more information, contact Jessica Householder at jhouseholder@hanson-inc.com.