Stephen Menzie / August 2020 – vol. 113, issue 8, pp 483–499 Stephen MenzieAbstract An understanding of the process of moult is a fundamental part of being able to determine the age and often the sex of an individual bird. In turn, establishing the age and sex of a bird correctly can be a key part of the process of identifying an unfamiliar bird. Compared with 20 years ago, the availability of good-quality photographs of most rarities means that ... This article is only available to registered users.To read more, please log in or purchase a subscription.