• Potential effects of offshore wind energy development on birds include reducing the detrimental impacts of climate change, physical habitat changes, bird behavioral changes, and changing bird mortality risks. • Seabird habitats and prey availability may change with new physical structures in the ocean and disturbance to the seafloor from offshore wind turbine and cable installation, changes to other human activities like fishing, and potential changes in oceanography. • Birds may change their behavior in response to offshore wind structures and activities primarily through attraction or avoidance at various scales. • Birds may collide with offshore wind infrastructure. Collisions are difficult to directly observe offshore, so collision risk models are generally used to estimate collision probability while direct detection methods (e.g., cameras and other technology in combination with visual observations) are developed and validated. • A combination of effects, or repeated exposure to one or more effects, may potentially have cumulative effects on bird behavior and survival over space and time. For more detailed information and scientific citations, please see the full FAQ document linked below.

• Potential risks to birds from offshore wind energy development are evaluated based on a combination of exposure (e.g., overlap in space/time between birds and wind facilities), effectors (the threat[s] posed by the wind facility), and vulnerability (e.g., how susceptible an individual bird or the bird species is to the threat). • Attributes of individual offshore wind facilities (including the physical presence of structures, associated lighting, and vessel traffic) can change birds’ habitat, resources, and foraging conditions. These shifts may exert positive, neutral, or negative effects on the surrounding ecosystem, and effects may change over the construction and operational periods of an offshore wind facility. • Various bird life history characteristics (such as flight height, body size, flexibility of habitat use, and migration strategy) factor into the potential level of risk posed by offshore wind energy development across individuals, populations, and species. For more detailed information and scientific citations, please see the full FAQ document linked below.

• Offshore wind facilities can kill birds directly through collisions and affect them indirectly through displacement and altered food availability. While it has been suggested that some of these indirect effects may increase energetic costs, there is currently no evidence of measurable impacts on the population level. • Studies using remote technologies (such as radar and cameras) in Europe and the U.S. indicate that bird collisions with offshore turbines are rare, in part because bird densities are generally low over open ocean relative to densities over land. • Measuring offshore collisions is inherently challenging compared to land-based sites because birds that collide with infrastructure fall into open water and become difficult to collect. Regulators address this by requiring reporting of any carcasses found on structures/vessels, deploying advanced remote tracking tools, and using collision risk models. • Offshore wind facility siting seeks to avoid sensitive habitat and areas frequented by migratory birds. Developers deploy a range of mitigation strategies across all facility phases (i.e., construction to decommissioning) to minimize risks, alongside pre- and post-construction monitoring technologies to inform adaptive management. • Offshore wind energy development causes a minor fraction of human-caused bird mortality compared to major land-based threats (such as cats and building collisions) or marine threats (such as invasive species and bycatch). Furthermore, renewable energy development has the potential to mitigate the severe long-term threat to global bird populations caused by climate change. For more detailed information and scientific citations, please see the full FAQ document linked below.

• Yes, offshore wind energy development has the potential to change bird behavior, movement patterns, and habitat use. Not all bird species appear to respond to offshore wind energy development, but the most common responses are avoidance and attraction. • Avoidance can occur at multiple scales. Birds can avoid an entire wind facility (“macro-avoidance”), avoid individual turbines (“meso-avoidance”), or make last-minute maneuvers around turbine blades (“micro-avoidance”). Macro-avoidance of wind facilities can lead to displacement and functional habitat loss. • Some birds may be attracted to offshore wind facilities due to increased perching, roosting, and foraging opportunities on and around offshore structures and vessels. Some birds may also be attracted to and disoriented by artificial lighting at night. • While research in Europe has shown behavioral responses, with some species (e.g., loons) more likely to avoid and/or be displaced by offshore wind energy development, and others (e.g., cormorants) more likely to be attracted to offshore wind facilities, transferability of these results to the U.S. wind context is uncertain. Variation in local species presence, wind facility layout, and geography likely influence how species respond. For more detailed information and scientific citations, please see the full FAQ document linked below.

• Many millions of birds use the waters off the U.S. Atlantic coast, but not all species using or migrating over this region will be affected by offshore wind energy development. • To date, most data on negative effects on birds from offshore wind energy development are from European studies. Bird collisions with offshore turbines appear to be rare, but effective habitat loss has been observed when some birds avoid specific areas of offshore wind energy development (i.e., displacement). However, impacts from collisions and displacement are difficult to measure at the population scale. • Improving our understanding of potential impacts to bird populations from offshore wind energy development is a focus of ongoing research globally. For more detailed information and scientific citations, please see the full FAQ document linked below.