Spatial distribution, demography and breeding biology of the Falklands skua of Sea Lion Island, Falkland Islands (2013-2019)

The dataseries comprises of data on nest location and spatial distribution, nesting habitat, demography, and reproductive success of the Falklands skua (Stercorarius antarctica antarctica) at two location in Sea Lion Island: 1) the lodge area, close to gentoo penguin colonies, and 2) the west end of the island, including the Sheffield Memorial area, close to the rockhopper penguin and king cormorants colonies. The data were collected during the 2013-2019 breeding seasons. Density and spatial distribution of nests in these two areas were quite different. In 2015-2016 a notable increase in the number of skua nesting pairs compared to the previous season was observed. Breeding success was high, and higher than the one reported for other breeding areas in the Falklands. On the contrary, in recent seasons a notable reduction in the number of skua nesting pairs and in the total breeding success of the population compared to the previous season was noted. The reduction in breeding success was stronger in the west end area. The reasons of this general reduction in success, and of the differential impact on the two different breeding areas, are unknown and deserve further investigation. Until now, effect of striated caracara predation, that was previously suggested as a potential regulator of skua demography, have been excluded. Further information is available on the research group website,

Data and Resources

Additional Info

Field Value
Last Updated December 21, 2020, 10:05 (PST)
Created January 30, 2020, 05:22 (PST)
Region Falkland Islands
Language eng
Topic Category Biota; flora and/or fauna in natural environment
Temporal Extent Start 2013-01-01
Temporal Extent End 2019-12-31
Dataset Reference Date 2019
Lineage Field work on skuas was carried at Sea Lion Island during the breeding season from 2013 to 2019. The whole island has been searched to identify skua nests. Skua are territorial, and, therefore, it is usually rather easy to identify nests by observing the behavioral reaction of the adults. After being located, skua nest were mapped using GPS receivers. Nests were given a serial number. Pictures of the adults were taken with a DSRL camera fitted with 100-400mm zoom to help visual identification of the members of the pairs. Displaying individuals and pairs were video recorded opportunistically with the same camera. Each nest was surveyed at least weekly, recording number of adults, eggs and chicks present, substrate and general habitat of the nest, aspect of the adults, and reaction towards approaching operators. Ad libitum notes about general and vocal behaviour, interaction between adults and chicks (including feeding events), and prey remains found around the nest were also collected .
West Longitude -59.1519
South Latitude -52.4486
East Longitude -59.0364
North Latitude -52.4205
Spatial Reference System WGS84
Responsible Organisation Name Hidden (personal data protection)
Contact Mail Address Hidden (personal data protection)
Responsible Party Role Hidden (personal data protection)
Access Limitations Restricted, send data request to data owner
Use Constraints Restricted, but open subject to limitations and prior agreement with responsible organisation. Copyright must be cited
Resource Reference Copyright ESRG 1995-present - All Rights Reserved. Please contact ESRG before citing unpublished reports.
Data Format shape, pdf
Update Frequency annually
Accuracy Accuracy of mapping by navigation grade GPS (e.g. daily mapping of males) is 5 metres; accuracy of mapping oby surveu grade GPS is submetric to decimetric. Collection of all other data is compliant to usual research standards, and a great effort is put to guarantee high repeatability, in particular for behavioural data.
Resource Type Dataseries
Original Title Hidden (internal use only)
Metadata Date 2019-04-03
Metadata Point of Contact
Contact Consent Contact details hidden
Unique Resource ID FK-ESRG-283

Dataset extent

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