This data set contains a zipped file with 8 individual .csv files used to support the analysis of survival bottlenecks presented by Hinke et al.(2020), "Acute bottlenecks to the survival of juvenile Pygoscelis penguins occur immediately after fledging". Data include geographical position estimates from satellite telemetry studies on Adélie (Pygoscelis adeliae), chinstrap (P. antarctica), and gentoo (P. papua) penguins tracked from the Antarctic peninsula region, carcass counts from ship and beach surveys in the study region, fledgling weights, and battery voltage data from telemetry tags.
Data were collected from several penguin monitoring sites in the Antarctic peninsula region, the South Orkney Islands, and East Antarctica between 1977 and 2017 using traditional and autonomous methods.Traditional methods consisted of researchers conducting direct observations of penguins throughout the season to record information on egg laying, incubation, and brood/guard periods. Simultaneously, autonomous methods consisted of time-lapse cameras deployed at the penguin colonies to photographically record the same daily nesting activities throughout the season. Seabirds observed in this study are Adélie (Pygoscelis adeliae), chinstrap (P. antarctica), and gentoo (P. papua) penguins.
At-sea distribution and density of marine mammals and seabirds. Seabird and marine mammal observations were collected from research vessels during transits between stations, to and from port of calls, etc.
Estimates of daily activity and consequent demand for food during winter are scarce for many polar seabirds, yet essential for assessing constraints on foraging effort, demand for food, and potential competition with local fisheries. We affixed archival temperature tags to gentoo penguins (Pygoscelis papua) from two colonies in the South Shetland Islands to measure the frequency, timing, and duration of foraging trips and to estimate minimum food requirements during winter. Foraging trip frequencies ranged from 0.85 to 1.0 trips day-1 and were positively correlated with day length. Early winter foraging trips more closely matched day length than late winter foraging trips. The data suggest that individuals maximize foraging time during the early winter period, likely to recover body mass following the breeding season and molt. The more attenuated response of foraging trip durations to increasing day length in late winter may be related to differences in local resource availability or individual behaviors prior to the upcoming breeding season. Minimum food requirements also exhibited a seasonal cycle with a mid-winter minimum. On average, minimum food requirements were estimated at 0.70 ± 0.12 kg day-1. Extrapolated to the regional population of gentoo penguins, winter food requirements by gentoo penguins were equivalent to roughly 33% of annual krill catches by commercial fisheries in the South Shetland Island region over the past decade. Current expansion of the gentoo population and the krill fishery in the southern Scotia Sea warrants continued monitoring of gentoo penguins during winter.