The U.S. Geological Survey, Western Ecological Research Center (USGS-WERC) was requested by the Bureau of Ocean Energy Management (BOEM) to create a database for marine birds of the California Current System (CCS) that would allow quantification and species ranking regarding vulnerability to offshore wind energy infrastructure (OWEI). This was needed so that resource managers could evaluate potential impacts associated with siting and construction of OWEI within the California Current System section of the Pacific Offshore Continental Shelf, including California, Oregon, and Washington. Along with its accompanying Open File Report (OFR), this comprehensive database can be used (and modified or updated) to quantify marine bird vulnerability to OWEIs in the CCS at the population level. For 81 marine bird species present in the CCS, we generated numeric scores to represent three vulnerability indices associated with potential OWEI: population vulnerability, collision vulnerability, and displacement vulnerability. The metrics used to produce these scores includes global population size, proportion of the population in the CCS, threat status, adult survival, breeding score, annual occurrence in the CCS, nocturnal and diurnal flight activity, macro-avoidance behavior, flight height, and habitat flexibility; values for these metrics can be updated and adjusted as new data become available. The scoring methodology was peer-reviewed to evaluate if the metrics identified and the values generated were appropriate for each species considered. The numeric vulnerability scores in this database can readily be applied to areas in the CCS with known species distributions and where offshore renewable energy development is being considered. We hope that this information can be used to assist meaningful planning decisions that will impact seabird conservation. These data support the following publication: Adams, J., Kelsey, E.C., Felis J.J., and Pereksta, D.M., 2016, Collision and displacement vulnerability among marine birds of the California Current System associated with offshore wind energy infrastructure: U.S. Geological Survey Open-File Report 2016-1154, 116 p., https://doi.org/10.3133/ofr20161154.

To better inform continued offshore wind energy development in the region, U.S. Geological Survey, Western Ecological Research Center (USGS-WERC) has updated the database of marine bird vulnerabilities to offshore wind energy infrastructure (OWEI) in the Pacific Outer Continental Shelf Region (POCS; waters within the Exclusive Economic Zone off California, Oregon, and Washington). The installation of OWEI at sea may affect marine birds by increasing the risk of mortality from collision with OWEI (Collision Vulnerability) and disturbance and displacement from suitable habitats (Displacement Vulnerability). For the marine bird species present in the POCS, USGS-WERC updated relative scores of Collision Vulnerability (CV) and Displacement Vulnerability (DV) to OWEI based upon new research and data, additional species present in the POCS, and an evolved understanding of the application and utility of the index. The metrics used to produce the CV and DV scores in the 2024 Vulnerability Index are flight activity, percent time spent flying at rotor swept zone height, macro-avoidance rate, and habitat specificity. Metric values were generated from over 150 published literature sources. The methods of generating metric values and calculating CV and DV from those values are described in the accompanying Data Report. This Vulnerability Index database can be used by the Bureau of Ocean Energy Management and other resource managers to evaluate potential impacts associated with siting and construction of OWEI within the POCS. For example, the relative vulnerability scores in this database can be compiled with species distribution and density information for areas in the POCS where offshore renewable energy development is being considered to evaluate potential marine bird impacts.

To better inform continued offshore wind energy development in the region, U.S. Geological Survey, Western Ecological Research Center (USGS-WERC) updated the database of marine bird vulnerabilities to offshore wind energy infrastructure (OWEI) in the Pacific Outer Continental Shelf Region (POCS; waters within the Exclusive Economic Zone off California, Oregon, and Washington). The installation of OWEI at sea may affect marine birds by increasing the risk of mortality from collision with OWEI (Collision Vulnerability) and disturbance and displacement from suitable habitats (Displacement Vulnerability). For the marine bird species present in the POCS, USGS-WERC generated relative scores of Collision Vulnerability (CV) and Displacement Vulnerability (DV) to OWEI. The references herein were used to generate these relative Collision Vulnerability and Displacement Vulnerability scores for the 89 marine bird species in the POCS.

Two metrics were used to determine Collision Vulnerability: Macro-avoidance and habitat flexibility. Macro-avoidance (MA)—The macro-avoidance values for species indicate the species-specific probability of avoidance for birds associated with wind power infrastructure. For each species, we derived this value from observed macro-avoidance rates (via human observation and radar) at existing offshore wind power sites. In cases where species-specific data were not available, we used information from similar taxa. Habitat Flexibility (HF)—the degree to which a species shows habitat-specific feeding strategies (habitat flexibility) influences its vulnerability for displacement by offshore infrastructure. We evaluated literature involving diet, feeding habits, and habitat use to estimate HF or each marine bird species in the CCS database. These data support the following publication: Adams, J., Kelsey, E.C., Felis J.J., and Pereksta, D.M., 2016, Collision and displacement vulnerability among marine birds of the California Current System associated with offshore wind energy infrastructure: U.S. Geological Survey Open-File Report 2016-1154, 116 p., https://doi.org/10.3133/ofr20161154. These data were revisied in June 2017 and the revision published in August 2017. Please be advised to use CCS_vulnerability_FINAL_VERSION_v10_DV.csv

Two metrics were used to determine Collision Vulnerability: Macro-avoidance and habitat flexibility. Macro-avoidance (MA)—The macro-avoidance values for species indicate the species-specific probability of avoidance for birds associated with wind power infrastructure. For each species, we derived this value from observed macro-avoidance rates (via human observation and radar) at existing offshore wind power sites. In cases where species-specific data were not available, we used information from similar taxa. Habitat Flexibility (HF)—the degree to which a species shows habitat-specific feeding strategies (habitat flexibility) influences its vulnerability for displacement by offshore infrastructure. We evaluated literature involving diet, feeding habits, and habitat use to estimate HF or each marine bird species in the CCS database. These data support the following publication: Adams, J., Kelsey, E.C., Felis J.J., and Pereksta, D.M., 2016, Collision and displacement vulnerability among marine birds of the California Current System associated with offshore wind energy infrastructure: U.S. Geological Survey Open-File Report 2016-1154, 116 p., https://doi.org/10.3133/ofr20161154. These data were revisied in June 2017 and the revision published in August 2017. Please be advised to use CCS_vulnerability_FINAL_VERSION_v10_DV.csv

Six metrics were used to determine Population Vulnerability: global population size, annual occurrence in the California Current System (CCS), percent of the population present in the CCS, threat status, breeding score, and annual adult survival. Global Population size (POP)—to determine population size estimates for each species we gathered information tabulated by American Bird Conservancy, Birdlife International, and other primary sources. Proportion of Population in CCS (CCSpop)—for each species, we generated the population size within the CCS by averaging region-wide population estimates, or by combining state estimates for California, Oregon, and Washington for each species (if estimates were not available for a region or state, “NA” was recorded in place of a value) and then dividing the CCSpop value by the estimated global population size (POP) to yield the percentage of the population occurring in the CCS. Annual Occurrence in the CCS (AO)—for each species, we estimated the number of months per year within the CCS and binned this estimate into three categories: 1–4 months, 5–8 months, or 9–12 months. Threat Status (TS)—for each species, we used the International Union for Conservation of Nature (IUCN) species threat status (IUCN 2014) and the U.S. Fish and Wildlife national threat status lists (USFWS 2014) to determine TS values for each species. If available, we also evaluated threat status values from state and international agencies. Breeding Score (BR)—we determined the degree to which a species breeds and feeds its young in the CCS according to 3 categories: breeds in the CCS, may breed in the CCS, or does not breed in the CCS. Adult Survival (AS)—for each species, we referenced information to estimate adult annual survival, because adult survival among marine birds in general is the most important demographic factor that can affect population growth rate and therefore inform vulnerability. These data support the following publication: Adams, J., Kelsey, E.C., Felis J.J., and Pereksta, D.M., 2016, Collision and displacement vulnerability among marine birds of the California Current System associated with offshore wind energy infrastructure: U.S. Geological Survey Open-File Report 2016-1154, 116 p., https://doi.org/10.3133/ofr20161154. These data were revisied in June 2017 and the revision published in August 2017. Please be advised to use CCS_vulnerability_FINAL_VERSION_v9_PV.csv

Six metrics were used to determine Population Vulnerability: global population size, annual occurrence in the California Current System (CCS), percent of the population present in the CCS, threat status, breeding score, and annual adult survival. Global Population size (POP)—to determine population size estimates for each species we gathered information tabulated by American Bird Conservancy, Birdlife International, and other primary sources. Proportion of Population in CCS (CCSpop)—for each species, we generated the population size within the CCS by averaging region-wide population estimates, or by combining state estimates for California, Oregon, and Washington for each species (if estimates were not available for a region or state, “NA” was recorded in place of a value) and then dividing the CCSpop value by the estimated global population size (POP) to yield the percentage of the population occurring in the CCS. Annual Occurrence in the CCS (AO)—for each species, we estimated the number of months per year within the CCS and binned this estimate into three categories: 1–4 months, 5–8 months, or 9–12 months. Threat Status (TS)—for each species, we used the International Union for Conservation of Nature (IUCN) species threat status (IUCN 2014) and the U.S. Fish and Wildlife national threat status lists (USFWS 2014) to determine TS values for each species. If available, we also evaluated threat status values from state and international agencies. Breeding Score (BR)—we determined the degree to which a species breeds and feeds its young in the CCS according to 3 categories: breeds in the CCS, may breed in the CCS, or does not breed in the CCS. Adult Survival (AS)—for each species, we referenced information to estimate adult annual survival, because adult survival among marine birds in general is the most important demographic factor that can affect population growth rate and therefore inform vulnerability. These data support the following publication: Adams, J., Kelsey, E.C., Felis J.J., and Pereksta, D.M., 2016, Collision and displacement vulnerability among marine birds of the California Current System associated with offshore wind energy infrastructure: U.S. Geological Survey Open-File Report 2016-1154, 116 p., https://doi.org/10.3133/ofr20161154. These data were revisied in June 2017 and the revision published in August 2017. Please be advised to use CCS_vulnerability_FINAL_VERSION_v9_PV.csv

Four metrics were used to determine Collision Vulnerability: Diurnal and nocturnal flight activity, flight-height (defined as time spent in rotor sweep zone), and macro-avoidance. Nocturnal flight activity (NFA) and diurnal flight activity (DFA)—Nocturnal and diurnal flight activity can influence the risk of collision; therefore, we used available information to estimate the amount of time each species spent flying during night and during day. Time spent in the rotor sweep zone (RSZt)— the percentage of time each species spends flying at the same height as wind turbine blades (as opposed to above or below the sweeping zone of the blades) will influence collision vulnerability. Based on flight-height analyses and published accounts, we estimated each species’ percentage of time flying within the rotor sweep zone (RSZ; 10-200 m above the water). Macro-avoidance (MA)—The macro-avoidance values for species indicate the species-specific probability of avoidance with wind power infrastructure. For each species, we derived this value from observed macro-avoidance (via human observation and radar) at existing offshore wind power sites. In cases where species-specific data were not available, we used information from similar taxa. These data support the following publication: Adams, J., Kelsey, E.C., Felis J.J., and Pereksta, D.M., 2016, Collision and displacement vulnerability among marine birds of the California Current System associated with offshore wind energy infrastructure: U.S. Geological Survey Open-File Report 2016-1154, 116 p., https://doi.org/10.3133/ofr20161154. These data were updated in August 2017: 5 values in the relative displacement vulnerability column have been updated. Users are advised to use the updated CSV: CCS_vulnerability_FINAL_VERSION_v10_CV.csv

Four metrics were used to determine Collision Vulnerability: Diurnal and nocturnal flight activity, flight-height (defined as time spent in rotor sweep zone), and macro-avoidance. Nocturnal flight activity (NFA) and diurnal flight activity (DFA)—Nocturnal and diurnal flight activity can influence the risk of collision; therefore, we used available information to estimate the amount of time each species spent flying during night and during day. Time spent in the rotor sweep zone (RSZt)— the percentage of time each species spends flying at the same height as wind turbine blades (as opposed to above or below the sweeping zone of the blades) will influence collision vulnerability. Based on flight-height analyses and published accounts, we estimated each species’ percentage of time flying within the rotor sweep zone (RSZ; 10-200 m above the water). Macro-avoidance (MA)—The macro-avoidance values for species indicate the species-specific probability of avoidance with wind power infrastructure. For each species, we derived this value from observed macro-avoidance (via human observation and radar) at existing offshore wind power sites. In cases where species-specific data were not available, we used information from similar taxa. These data support the following publication: Adams, J., Kelsey, E.C., Felis J.J., and Pereksta, D.M., 2016, Collision and displacement vulnerability among marine birds of the California Current System associated with offshore wind energy infrastructure: U.S. Geological Survey Open-File Report 2016-1154, 116 p., https://doi.org/10.3133/ofr20161154. These data were updated in August 2017: 5 values in the relative displacement vulnerability column have been updated. Users are advised to use the updated CSV: CCS_vulnerability_FINAL_VERSION_v10_CV.csv