Cooperative Fish and Wildlife Research Units Program: South Carolina
Education, Research and Technical Assistance for Managing Our Natural Resources

The black-capped petrel (Pterodroma hasitata) is an endangered seabird endemic to the western north Atlantic. Although estimated at ~1,000 breeding pairs, only ~100 nests have been located at two sites in Haiti and three sites in the Dominican Republic. At sea, the species primarily occupies waters of the western Gulf Stream in the Atlantic and the Caribbean Sea. Due to limited data, there is currently not a consensus on the geographic marine range of the species although no current proposed ranges include the Gulf of Mexico. Here, we report on observations of black-capped petrels during two vessel-based survey efforts throughout the northern Gulf of Mexico from 2010 - 2011 and from 2017 - 2019. During 558 days and ~54,700 km of surveys we tallied 40 black-capped petrels. Most observations occurred in the eastern Gulf, although birds were observed over much of the east-west and north-south footprint of the survey area. Predictive models indicated that habitat suitability for black-capped petrels was highest in areas associated with dynamic waters of the Loop Current. We used the Extent of Occurrence (EOO) and Area of Occupancy (AOO) concepts to delimit the geographic range of the species within the northern Gulf of Mexico. We suggest that the marine range for black-capped petrels be modified to include the northern Gulf of Mexico, recognizing that distribution may be more clumped in the eastern Gulf and that occurrence in the southern Gulf remains unknown due to a lack of surveys there. To date, however, it remains unclear which nesting areas are linked to the Gulf of Mexico.