The associations between weather and topography on golden eagle flight behaviour at a wind farm in the Canadian rockies.

I documented flight tracks of migratory golden eagles in proximity to a pre-operational wind farm in northeast British Columbia, Canada. This is the first Canadian research along a golden eagle migration corridor that indentifies weather and topographic factors associated with flight altitudes in relation to a proposed ridge-top wind farm development. In both spring and fall migration seasons (2008-2010) I documented golden eagle flight behavior in two parts: (1), to determine what temporal, spatial and/or weather variables were associated with eagle flights near the proposed ridge-top turbine string (called the risk-zone) and (2), to determine if weather, topography and/or flight behaviour were associated with eagle altitudes as they entered the risk-zone. I found entries into the risk-zone were positively correlated with hourly passage rates across all years and between seasons. For eagles that entered the risk-zone, flight altitudes increased with increasing wind speed, were lower under head-winds compared to cross- and tail-winds, and were lower over sloped compared to flat ridge-top topography. Post-construction observations are needed to quantify avoidance behaviours in addition to wind data collected near turbine height. I highlight the need for a Cumulative Impact Assessment for the region to oversee the potential accumulation of small impacts on golden eagles at the population level. --P. ii.