Pigeon Guillemot Restoration Research in Prince William Sound, Alaska 2012-2023

This dataset describes cruise-based seabird observations in Prince William Sound, Alaska, conducted as part of the Pigeon Guillemot Restoration project, funded by the Exxon Valdez Oil Spill Trustees' Council. Historically, the Naked Island Group had the largest breeding population of pigeon guillemot (Cepphus columba) in Prince William Sound (PWS), Alaska, but it declined over 90% after the 1989 Exxon Valdez Oil Spill. Following the effects of the oil spill, predation of adults and their nests by introduced American mink (Neovison vison) was the primary factor limiting population recovery. During a 5-year pigeon guillemot restoration project, which included mink removal from guillemot nesting areas, counts of pigeon guillemots at Peak, Naked and Story islands have more than doubled from 2014-2018 (69 to 167 individuals) and numbers of known nests increased more than four times (11 to 51 nests). In 2019, we began a second 5-year monitoring effort (2019-2023) at the Naked Island Group. Our objectives were to: (i) search for evidence of mink in guillemot breeding areas, (ii) monitor the recovery of pigeon guillemots, and (iii) monitor relative food availability, using black-legged kittiwakes (Rissa tridactyla) as indicators.Our 2021 effort to continue monitoring the population recovery of pigeon guillemots at the Naked Island Group was highly successful. No mink were recorded visiting bait stations and no mink tracks were observed at the 10 high-use areas identified during previous intensive trapping efforts. Guillemot population counts were conducted in early June 2021 and numbers of guillemots continued to increase at the Naked Island Group compared to previous years (2014-2019). Nest counts of black-legged kittiwakes were conducted and while results are pending, preliminary indications are that 2021 has been a “poor” year for fish availability in PWS. Together, these data will inform future management actions by determining if mink are absent from the islands, measure the rate of recovery of pigeon guillemots following the removal of mink, and provide an indicator for productivity patterns of ocean conditions, which will assist interpretation of pigeon guillemot population trends.