Dominic Couzens on the Crossbill

Available for over a year

A new series of Tweet of the Day for Sunday morning revealing personal and fascinating stories from some fresh voices who have been inspired by birds, their calls and encounters. Crossbills are not born with crossed bills, not only that but as they develop their crossing bills, after their 27th day from hatching, their bills can cross either to the left, or cross to the right. It is a 50:50 split. A superb evolutionary adaption but as ornithologist Dominic Couzens explains, it means their diet is limited to conifer seeds or nothing.. In Britain we have the common crossbill and the Scottish crossbill. Whether these are separate species or the same species, the argument continues. Producer : Andrew Dawes, BBC Audio, Bristol Studio Engineer : Ilse Lademann