Chiffchaffs wintering at a sewage works in south Devon

Alan Pomroy

Age and sex

First-years comprised 81.6% of new birds captured in this study (n=185). Moreno-Opo et al. (2015) found that age ratio differed significantly according to wintering region, with a higher percentage of first-years in the Iberian Peninsula and Morocco (81.3%, n=874) than south of the Sahara (54.7%, n=185).

In this study, 199 out of 238 winter birds were sexed by wing l

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