Ageing and sexing the Yellowhammer Emberiza citrinella caliginosa during the non‐breeding season

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.

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Correspondence author Email: [email protected]