Biometry and resightings of dark-bellied brent geese captured on Terschelling island in 2005, 2010, 2011, 2013, 2014 (i.e. successful breeding years in the arctic when birds returned with juveniles) as obtained from the geese.org database (accessed 24 Feb 2016). For details, see main manuscript.

code: color ring code
catch_date: date of capture
sex: sex as determined by cloacal inspection
weight: weight at capture in grams
NObs: number of resightings of the bird after the breeding season, i.e. between 1-Sep-(year catch_date) and 1-June-(year catch_date + 1)
NYoung: maximum number of accompanying young observed after the breeding season, i.e. between 1-Sep-(year catch_date) and 1-June-(year catch_date + 1)
wing_len: wing length at capture in mm
head_len: head length (including beak) at capture in mm