Eagle Flight Behavior and Risk from Wind Energy

Eagle flight behavior and risk from wind energy TODD KATZNER, U.S. Geological Survey Tricia A. Miller, Conservation Science Global, NJ, USA Adam E. Duerr, Bloom Biological, PA, USA Melissa A. Braham, West Virginia University, WV, USA Michael Lanzone, Cellular Tracking Technologies, NJ, USA David Brandes, Lafayette University, PA, USA Jeff Cooper, Virginia Department of Game and Inland Fisheries, VA, USA U.S. Department of the Interior U.S. Geological Survey

Eastern Golden Eagles 

Aquila chrysaetos canadensis

small population 5,000 -10,000 geographically and genetically distinct migratory breeders in Maine until 1997  extirpated by DDT conservation concern  Mammal traps  lead poisoning  rodenticides/poisons  collisions   

vehicles power lines wind turbines

Eastern Golden Eagles 

Research goals

 Telemetry to understand flight behavior, habitat use and predict risk from turbines

How do birds fly? 

Flapping flight



Subsidized flight

 Thermal soar – glide  Orographic soaring  Dynamic soaring  Contorted soaring

Subsidized Flight  Thermal   

 

sun heats ground ground heats air hot air rises

Orographic



horizontal winds deflected upwards

Dynamic (oceanic) & Contorted (terrestrial)

How do we study bird flight? 

Telemetry

 Trap & telemeter ~85 golden  



eagles (winter) ARGOS satellite telemetry  1-hr GPS data GPS-GSM systems  15-min or 30-sec GPS data

Data analysis – statistical models to identify predictors of flight behavior

Eastern Golden Eagles 

Telemetry to understand flight behavior, habitat use and predict risk from turbines

 Response to variation in 

 Topography  Weather Ultimate goal:

 predict risk from

wind turbines



Responses –

 flight altitude  flight behavior

Flight altitude response 

Topography

 flight altitude linked to landform birds flying over

Flight altitude response 

Weather

 as wind speed increases, eagles change altitude less

Flight behavior  

Flight altitude responds to topography and weather Hypothesis: the flight altitude response is indicative of changing behavior by eagles

 switching from use of thermal updraft to use of orographic updraft

Early Spring

Late Spring

Strong W

Weak

Strong E

Flight behavior  

Flight altitude responds to topography and weather Hypothesis: the flight altitude response is indicative of changing behavior by eagles

 switching from use of thermal updraft to use of orographic updraft



Flight behavior switches in response to availability of updraft



Has consequences for risk from turbines…..