Abstract

Individual- or population-level analyses using ringing data require accurate identification of the age and
sex of birds in the hand. Many species are difficult to age and sex: work on birds of known age and
sex is essential if we are to increase the value of ringing data for these species. In this study we have
used molecular sexing techniques and known-age birds to characterise plumage characteristics useful in
distinguishing the age and sex of Yellowhammers Emberiza citrinella caliginosa. Tail-feather shape was
useful in ageing both adult and first-year birds, supporting current ageing criteria; other features were
associated with first-year birds but not with adults. Most birds, but not all, could be sexed using the amount
of yellow visible on the side of head and crown. The amount of black on the longest tail-covert shaft and the
amount of white on the fifth and sixth tail feathers were useful for identifying both sexes. The rump-feather
shaft colour and under-tail covert coloration may be useful for sexing ambiguous birds. Our results provide
additional ageing and sexing criteria for E. c. caliginosa and can be used to improve the accuracy of
ringing data for this declining subspecies.