Bald Eagles and Bird Strikes
My investigative search gained momentum with a call to Bruce McKinnon, Transport Canada’s Wildlife specialist. He is the editor of “Sharing the Skies: An Aviation Industry Guide to the Management of Wildlife Hazards”. This publication proved to be a veritable encyclopedia on wildlife encounters in aviation. It has widespread application from community leaders to waste disposal companies. Chapter 10 - “Solutions - Pilots” is a must read. The section on Flight Planning and Operating Principles covers strategy to minimize risk and initiatives to take in the event of a bird strike. One statement in particular caught my attention: “Birds of prey have been reported to attack aircraft”. - Q.E.D.! This strengthens my suspicion that my introductory vignettes were not chance encounters but hunter - prey scenarios with the aircraft fulfilling the role of prey!
Comment by David Hancock, Pilot / Biologist - I think this is carrying fantasy a little far. Play, or even perceived defense of their nesting territory - and most of the incidents described above are not defense of territory, nor are they examples of “an eagle hunting an aircraft”. Your implication of the aircraft as prey is simply not true. If they wanted to do that, on a fanatical suicide mission, there would most certainly be no planes. Eagles love to soar on the wind, they develop aerial skills by chasing and joy riding to display and improve their life giving aerial talents. It was this admiration of falcon and eagle flight skills that made me want to fly. Certainly here on the west coast, particularly along the Pacific Flyway where there are more waterfowl and raptors than almost anywhere in North America, it behooves pilots intruding the birds airspace to be vigilant for them. I am always surprised that the millions of waterfowl and gulls result in so few impacts.
The interpretation that an eagle, in close proximity to an aircraft, particularly on a collision course, has it legs out is to be interpreted as aggressive is simply misunderstanding eagles’ behavior. It is similar to the earlier comment I made about people misunderstanding why eagles lock talons and come tumbling earthward. As any pilot can understand any two aircraft coming from different directions and locking wheels are likely to have some airfoil disruption! If now you are a pursued eagle, one who has another eagle bearing down on you in hot pursuit, probably because you are in a neighbors territory - or maybe just in exuberant play - and the pursuer is about to put his talons in your back what do you do? Only one thing. You do a roll and throw your talons up to meet those of the aggressor - the cartwheel is the obvious outcome. Now take the eagle soaring lazily on a thermal, probably watching for food or playing on the wind, and along comes an aircraft on a collision course - and coming very fast!! What does the eagle do? If it can’t readily evade and if a collision is possibly imminent a logical maneuver I would suggest is to put up your only defense - instinctively you raise your hands to ward off a blow - sorry that was to be the eagle warding off the blow so it puts up its talons. Attack or defense mode? You call it.
When I drive I worry about cars going off track, a drunk or incompetent driver doing the unpredictable, mechanical failure or something falling off a passing vehicle. In the air I add in the real potential hazard of hitting a bird - and I try and watch more carefully. If you are really concerned, and you should be, then reduce your flying in the major bird migration routes and times.
Chapter 6 - “Airports” provided more food for thought. The diagram of hazardous zones adjacent to an airport indicates that extremely hazardous sites such as garbage dumps and food waste landfill locations should be no closer than 8 km radius from the airport reference point. My home base, Boundary Bay, is sandwiched between Mud Bay to the south and a landfill site and pond just north of the circuit. Rare is the day that the adjacent airspace is not humming with transiting seagulls, ducks, and great blue herons as soaring hawks and bald eagles compete for a sequence in the circuit - a recipe for disaster!