Wildlife Hazard Management Program at Denver International Airport
Colorado is known around the world for its robust wildlife and natural beauty. But animals and aircraft don’t mix, which is why Denver International Airport (DEN) incorporates a comprehensive wildlife hazard management plan that focuses on protecting the safe operation of more than 565,000 aircraft movements every year.
About the Plan
The airport’s wildlife hazard management program is conducted under the guidance of an FAA-approved Wildlife Hazard Management Plan (WHMP), which guides airport personnel and wildlife professionals on making responsible wildlife management and wildlife mitigation recommendations and decisions.
- The FAA mandates all certificated airports, which includes DEN, to conduct a Wildlife Hazard Assessment which includes an analysis of wildlife attractants within 10,000 feet and a 5-mile radius of the airport.
- The WHMP at DEN places a strong emphasis on “harassment and hazing” of wildlife to ensure that wildlife incidents are mitigated using non-lethal methods and technologies whenever possible.
- DEN mitigates wildlife habitat to the extent possible to alleviate the attractant, including: filling in ponds and water sources, if practicable, and vegetation management (managing grass height depending on bird species that use them).
- The U.S. Department of Agriculture (USDA) relies on wildlife harassment tools to mitigate wildlife hazards. Those tools include: sirens, wildlife patrols, pyrotechnics, trapping and removing, and lethal removal if necessary to protect aircraft.
DEN partners with the USDA’s Wildlife Services, which provides four full-time USDA personnel to perform wildlife management at the airport year round. DEN operational staff also receive required annual training on wildlife mitigation in order to better assist and cooperate with the work done by the USDA. DEN and the USDA share a common goal of protecting aviation and public safety by ensuring runways and roads are cleared of potential wildlife hazards for the safety of the traveling public. The Federal Aviation Administration (FAA) sets guidelines that DEN and USDA adhere to regarding wildlife management standards and recognizes that importance of reporting wildlife activity on and around the airport. FAA controllers also play an important role in managing wildlife by relaying pilot reports of birds and other wildlife hazards to crews on the ground, and alerting pilots in the air of known or anticipated wildlife hazards.
Orville Wright documented the first known bird strike, or collision with an aircraft, during a flight over a corn field near Dayton, Ohio in 1905. Since 1990, the FAA has collected voluntary bird strike reports and maintained a bird strike database. The database is managed by the Wildlife Services Program of the U.S. Department of Agriculture under terms of an interagency agreement with the FAA. According to the FAA, birds make up 97 percent of all reported wildlife strikes on an aircraft. But the number of strikes is not indicative of the success or failure of an airport’s wildlife management program. Every airport faces unique challenges associated with bird activity, which can be influenced by an airport’s size, strike reporting awareness, geographic location, migratory patterns, species and other factors. In 2014, DEN was one of five finalist for the FAA’s inaugural Strike Reporting Excellence Award for its robust reporting program.
The USDA possesses a federal banding permit for trapping, banding and relocation of birds of prey species. The USDA maintains multiple bird traps located throughout the airfield that are used to humanely trap and relocate large birds of prey. The U.S. Fish and Wildlife Service works with the USDA and DEN to track certain animals that are relocated from the airport. A Golden eagle (seen to the right) that was captured and relocated in mid-2014, for example, continues to provide its location via GPS and has been living in the Laramie, Wyoming area.
- There is no particular “bird season” at DEN. In the spring and summer, juvenile birds are flying about, trying to learn to hunt and survive. In the fall, hawks are looking for rodents in the wide open spaces. In the winter, large flocks of migrating geese tend to bunch together.
According to the FAA, the reported costs for civil aircraft wildlife strikes from 1990-2012 totaled $639 million (Dolbeer et al 2014). The FAA maintains a searchable database of all reported wildlife strikes. The annual cost of wildlife strikes to the civil aviation industry in 2015 was projected to be a minimum of 69,497 hours of aircraft downtime and $229 million in direct and other monetary losses.
No airport in the United States has a fully developed avian radar system. In fact, the only systems in the U.S. are FAA-sponsored research and development sites. DEN has previously evaluated avian radar that is currently in development, but the technology is not yet a good fit for DEN for various reasons:
- There is a vast difference between the expectations and the capability of existing avian radars.
- DEN is the largest airport in North America, at 53 square miles, and existing avian radar systems have not been proven to be effective for DEN's size.
- Current technology cannot identify bird species or accurate altitude of birds, and has other limitations that make these systems impractical for DEN. Through a nationwide network of research professionals, the USDA and DEN continue to evaluate new technology and emerging best practices, however.
- USDA currently monitors wildlife activity in the field and can immediately detect and notify tower or airport operations personnel of the impending threat and can also work immediately to alleviate the threat posed to aircraft. In addition, USDA personnel monitor wildlife activity and collect data through the use of GIS technology which illustrates historical trends similar to that of radar at a significantly lower cost.
- Although rabbits and prairie dogs do not pose an immediate threat to aircraft, they attract numerous predators including hawks, owls, and coyotes which are frequently struck by aircraft. The USDA destroys prairie dog burrows and removes rabbits and prairie dogs to prevent them from attracting larger wildlife that could post a threat.
DEN is located on 53 square miles of property that includes agriculture practices, vegetation, structures and drainage that may attract wildlife. DEN works cooperatively with the USDA to identify areas of the airport for mitigation that helps prevent wildlife from being attracted to the airfield. In addition, the WHMP provides updates and priorities for habitat management and recommendations each year.
- DEN operates 17 large mowers that cut vegetation throughout the property each year, as weather and topography permits, to reduce available habitat for multiple wildlife species including blackbirds, coyotes and rabbits. In fact, it is estimated that DIA has spends more than 11,000 hours on annual mowing activities.
- DEN in 2009 and 2015 constructed concrete trickle channels to improve water drainage and remove cattails near taxiways and runways. Since the improvements, wildlife strike incidents and activity have been reduced in those areas and wildlife activity will continue to be monitored.
Dolbeer, R. A, S. E. Wright, J. Weller, M.J. Begier. 2014. Wildlife Strikes to Civil Aircraft in the United States 1990-2013. Federal Aviation Administration, National Wildlife Strike Database Serial Report #20, Office of Airport Safety and Standards, Washington, D.C.
Federal Aviation Administration. Department of Transportation. 2004. Advisory Circular 150/5200-32A, Reporting Aircraft Wildlife Strikes.
Federal Aviation Administration. Department of Transportation. 2007. Advisory Circular 150/5200-33B, Hazardous Wildlife Attractants on or Near Airports.
United States Department of Agriculture, Animal Plant Health Inspection Service, Wildlife Services. 2012. KDEN Wildlife Hazard Assessment. 78 pp.
USDA, APHIS, Wildlife Services. 2015 Revision. KDEN Wildlife Hazard Management Plan.