Acute bottlenecks to the survival of juvenile Pygoscelis penguins

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.

Multiple datasets are provided. Telemetry data is raw ARGOS data collected from Sirtrak Kiwisat K2G-72A transmitters on Adelie, gentoo, and chinstrap fledlging penguins. Summarized data on cumulative losses of tags from adult birds dervie from Wildlife Computers Spot-275 transmitters. Historical raw data collected by field researchers include fledgling weights and counts of penguin carcass observed at sea and on beaches. Fledgling weights are were collected with spring scales immediatley prior to first departure of fledgling penguins from their natal colony (Adelie and chinstrap) or at a standard age of 85-days after hatch (gentoo). At-sea carcass observations were collected during standard seabird surveys while underway during daylight hours. Beach-cast carcasses of fledgling chinstraps were counted one week after the fledging period at Cape Shirreff, Livingston Island. Recruitment data are based from mark-recapture data and represent proportional returns of individuals from marked cohorts, as updated from a prior report (doi: 10.1007/s00442-007-0781-4)

Estimating when and where survival bottlenecks occur in free-ranging marine predators is critical for effective demographic monitoring and spatial planning. This is particularly relevant to juvenile stages of long-lived species for which direct observations of death are typically not possible. We used satellite telemetry data from fledgling Adélie, chinstrap and gentoo penguins near the Antarctic Peninsula to estimate the spatio-temporal scale of a bottleneck after fledging. Fledglings were tracked up to 106 days over distances up to 2140 km. Cumulative losses of tags increased to 73% within 16 days of deployment, followed by an order-of-magnitude reduction in loss rates thereafter. The timing and location of tag losses were consistent with at-sea observations of penguin carcasses and bioenergetics simulations of mass loss to thresholds associated with low recruitment probability. A bootstrapping procedure is used to assess tag loss due to death versus other factors. Results suggest insensitivity in the timing of the bottleneck and quantify plausible ranges of mortality rates within the bottleneck. The weight of evidence indicates that a survival bottleneck for fledgling penguins is acute, attributable to predation and starvation, and may account for greater than or equal to 33% of juvenile mortality.

This international collaborative study includes data provided by researchers from the the following groups:

1 Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, U.S.A.

2 Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, U.S.A.

3 Departamento Biología de Predadores Tope, Instituto Antártico Argentino, San Martín B1650CSP, Argentina

4 Laboratorios Anexos, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, La Plata B1904AMA, Argentina

Hinke JT, Watters GM, Reiss CS, Santora JA, Santos MM. 2020. Data sets supporting "Acute bottlenecks to the survival of juvenile Pygoscelis penguins occur immediately after fledging". Dryad Digital Repository. (doi: 10.5061/dryad.2v6wwpzkh)

Hinke Jefferson T., Watters George M., Reiss Christian S., Santora Jarrod A. and Santos M. Mercedes. 2020. Acute bottlenecks to the survival of juvenile Pygoscelis penguins occur immediately after fledging. Biol. Lett. 16: 20200645.

https://doi.org/10.1098/rsbl.2020.0645

Any conclusions drawn from the analysis of this information are not the responsibility of NOAA, the National Marine Fisheries Service, US AMLR or its partners.

FAO Area 48.1, CCAMLR Area 48.1, Antarctic Peninsula, South Shetland Islands, South Orkney Islands

Available online at https://doi.org/10.5061/dryad.2v6wwpzkh

https://doi.org/10.5061/dryad.2v6wwpzkh

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Data were collected using agreed, standard field protocols.

Data are stored on a server at the Southwest Fisheries Science Center which has all appropriate access controls, and archived at the NCEI with assigned DOI (see title section for DOI information).

Raw data are collected by researchers at land based stations, entered into data files, reviewed for QA/QC and later on shore-based servers.