Population monitoring of Brown Skua at Bird Island, South Georgia, from 2011 onwards (https://data.bas.ac.uk/metadata.php?id=GB/NERC/BAS/PDC/01205), accessed by contacting UK Polar Data Centre at polardatacentre@bas.ac.uk, [date in here dd/mm/yyyy]

We would strongly encourage contacting Richard Philips (raphil@bas.ac.uk ) for more information regarding this dataset, including guidance on its reuse.

Methodology:

Individual nests are visited several times during the breeding season. The exact coordinates of the nest and the identity of the adults are recorded, utilising the unique legring number of the adults if present. The number of eggs laid, hatching date, fail date if applicable and number eggs hatching are recorded. The egg dimensions are measured for year-on-year comparison. Non breeders present in the study colonies are noted, and identifiable dead skuas are also recorded.

Chicks are then counted and monitored at 45 days of age, and those still alive have wing length measured and weight recorded. A proportion of the young are ringed for future monitoring.

Methods for sexing ringed birds have varied and the codes for these methods are as follows: O = old data (ringed birds sexed by Sheffield), N = sexed from gel in 2013, N2 = sexed as male from gel but retested using tape station and sexed as female, P = partner sexed by association, S = sexed from relative size, D = sexed by dissection.

All data were collected under permit from the Government of South Georgia and the South Sandwich Islands.

All sampling procedures used were regulated by the British Antarctic Survey Ethical Review Committee in collaboration with Cambridge University and the UK Home Office.