Mapping of higher predators from aerial and satellite imagery on Zavodovski Island, South Sandwich Islands, 2010 to 2025
GB/NERC/BAS/PDC/02256
Abstract:
This dataset contains spatial data mapping the location of higher predators on Zavodovski Island, South Sandwich Islands. The dataset comprises polygon shapefiles delineating colonies of chinstrap penguins (Pygoscelis antarcticus), macaroni penguins (Eudyptes chrysolophus), southern giant petrels (Macronectes giganteus), and Antarctic fur seals (Arctocephalus gazella), together with point locations of king penguins (Aptenodytes patagonicus) and individual chinstrap and macaroni penguin nests. These data were derived from high-resolution aerial imagery collected during a drone survey of the island on 14 December 2023. In addition, colony boundary shapefiles for chinstrap and macaroni penguins derived from commercially available satellite imagery are provided for 2011, 2016, 2020, 2022, and 2025.
The drone survey allows an accurate assessment of the status of predators during the 2023-24 breeding season that forms a baseline for future surveys. They also allow estimation of nesting density that can be extrapolated by colony areas derived from the satellite surveys, producing population trends over the previous 14 years.
These data were collected as part of a wider project to establish a baseline for monitoring penguin populations and terrestrial biodiversity on Zavodovski Island; a globally important but data-deficient area of high biodiversity. The dataset supports investigations of species distribution, population trends, and ecosystem change, and will contribute to evidence-based conservation and management planning for the South Sandwich Islands, including the development and refinement of marine and terrestrial protected areas.
Darwin Plus (DPLUS 186) 'Evidence-based conservation of key biodiversity in the South Sandwich Islands' funded the project, with contributions from the Antarctic Research Trust and Talesmith.
Citation:
Ratcliffe, N., Dickens, J., & Clucas, G. (2026). Mapping of higher predators from aerial and satellite imagery on Zavodovski Island, South Sandwich Islands, 2010 to 2025 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/7220dc6b-2f52-4160-a6c0-e57c50963308
Access Data
GET DATA:
License
| Access: | The data are under embargo until publication of the associated manuscript; estimated Nov 2026. |
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| Use: | This data is governed by the NERC data policy http://www.nerc.ac.uk/research/sites/data/policy/ and supplied under Open Government Licence v.3 http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/. |
Basic Information
| Creation Date: | 2026-08-07 |
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| Dataset Progress: | Complete |
| Dataset Language: | English |
| ISO Topic Categories: |
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| Parameters: |
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Additional Information
| Reference: | These data are used in an accepted article in Current Biology: 'Population declines and changes in community composition at the world's largest penguin colony'. | |
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| Quality: | The drone survey ground sampling distance was 1.9 - 2.7 cm and the satellite surveys have a resolution of 30 - 50 cm. Coverage in all surveys exceeded 90% of the area occupied by predators. | |
| Lineage/Methodology: | Zavodovski Island was visited during a yacht-supported expedition between 10 and 16 December 2023. A Mavic 3T quadcopter (DJI, Shenzhen, China) with a CMOS half inch 48 mega pixel sensor and 24 mm lens was used to collect aerial imagery of penguin colonies across almost the whole island on 14 December 2023, which coincided with the incubation period of both macaroni and chinstrap penguins. The flight plan was programmed in the DJI Pilot application to provide 70% image overlap at an altitude of 70m -100 m above ground level, resulting in a ground sampling distance of 1.9 - 2.7 cm. The drone survey achieved almost complete coverage of the penguin occupied area of the island, with the exception of chinstrap colonies on the southwestern plateau and at Stench Point. Drone images were processed into orthomosaics using the Pix4D 4.9.0 package (Lausanne, Switzerland) in three spatial blocks covering the north, east and south sectors of the island. Both the digital elevation model (DEM) and orthorectified mosaic were then exported as tif files, with the projection UTM 26S and EGM2008 geoid (EPSG 32726). Polygons were drawn around the sub-colony boundaries on the orthomosaic for each species in ArcGIS Desktop 10.6 (Esri, Redlands, USA). A semi-automated classifier was developed that marked chinstrap and macaroni penguin nests within the clipped boundaries of the colony polygons, based on colour and spacing. Chinstraps have blue-toned backs, lower nesting density and guano rings around their nests which allows their sub-colonies to be distinguished from those of the black-backed, denser nesting macaronis. Calibrations of classifier vs. manual counts of nests were conducted within 114 5 x 5m quadrats positioned across the island at varying overall density and species composition. Chinstrap and macaroni penguin colony boundaries were digitised on satellite images from Vantor and Airbus, taken between December and March in 2010, 2011, 2016, 2020, 2022 and 2025. Gaps in coverage caused by cloud cover were filled using colony polygons from the image closest in time in which the missing area was clearly visible. Details of the images used to produce the points and polygons are provided in the file layer_descriptions.csv. The satellite imagery used are the property of Vantor or Airbus, so users seeking to acquire these will need to purchase the images from these companies directly. The BAS Mapping and Geographic Information Centre (MAGIC) provided the coastline data for the file zavodovski_coastline_2023.shp. |
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ASSOCIATED DATA SET(S):
- 10.5285/459597b2-ca0c-4110-b59c-62490867f348
- 10.5285/529808a4-3967-49fe-abf6-fdb4fe5a7e5e
- 10.5285/96febb5d-1821-4f49-9b5f-32e489ae3839
- 10.5285/e2f65907-7aaa-4a45-917c-6f31ca644ad6
PROJECT HOME PAGE:
SOFTWARE PACKAGES:
Extent
| Temporal Coverage: | |
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| Start Date | 2010-12-09 |
| End Date | 2025-01-12 |
| Spatial Coverage: | |
| Latitude | |
| Southernmost | -56.32441 |
| Northernmost | -56.27715 |
| Longitude | |
| Westernmost | -27.62803 |
| Easternmost | -27.53531 |
| Altitude | |
| Min Altitude | 70m |
| Max Altitude | 100m |
| Depth | |
| Min Depth | N/A |
| Max Depth | N/A |
| Data Resolution: | |
| Latitude Resolution | N/A |
| Longitude Resolution | N/A |
| Horizontal Resolution Range | < 1 meter |
| Vertical Resolution | N/A |
| Vertical Resolution Range | N/A |
| Temporal Resolution | N/A |
| Temporal Resolution Range | N/A |
| Location: | |
| Location | South Sandwich Islands |
| Detailed Location | Zavodovski Island |
Instrumentation
| Sensor(s): |
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| Source(s): |
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| Data Collection: | Drone imagery: Mavic 3T quadcopter (DJI, Shenzhen, China) with a CMOS half inch 48 mega pixel sensor and 24 mm lens. Satellite imagery: Vantor WorldView-2 Vantor Worldview-3 Vantor GeoEye-1 Airbus Pleiades |
Storage
| Distribution: | |
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| Distribution Media | Online Internet (HTTP) |
| Distribution Size | 34 MB |
| Distribution Format | SHP |
| Fees | N/A |
| Data Storage: | 28 x .shp and associated files [34 MB] 2 x .csv files: validation.csv [4 KB] - Calibration data of manual vs classifier penguin counts. inc_chin - Manual count of incubating chinstrap penguins inc_mac - Manual count of incubating macaroni penguins od_chin - Manual count of 'off-duty' chinstrap penguins od_mac - Manual count of 'off-duty' macaroni penguins auto_chin - Semi-automated classifier count of chinstrap penguins auto_mac - Semi-automated classifier count of macaroni penguins layer_descriptions.csv [8 KB] - Data dictionary. |