Proportion of time that Pacific Flyway geese are at risk of wind-turbine strikes during transoceanic migrations

Renewable energy facilities are a key part of mitigating climate change, but can pose threats to wild birds and bats, most often through collisions with infrastructure. Understanding collision risk and the factors affecting it can help minimize impacts on wild populations. For wind turbines, flight altitude is a major factor influencing collision risk, and altitude-selection analyses can evaluate when and why animals fly at certain altitudes under certain conditions. To provide information about collision risk to the Bureau of Ocean Energy Management (BOEM), the USGS used GPS tags to track geese on transoceanic migrations between Alaska and the Pacific Coast of the contiguous U.S., an area where offshore windfarm development is beginning. We evaluated how geographic and environmental covariates affected 1) whether birds were at rest on the water versus in flight and 2) altitude selection when in flight.