Aging Atlantic Puffins Fratercula arctica in summer and winter

Abstract

Atlantic Puffins Fratercula arctica in summer and winter plumage can be aged as first-year, second-year, third-year, young adult and old adult using the number of grooves on the outer part of the beak. The technique is useful to bird ringers and those dealing with birds found dead in wrecks and pollution incidents where knowledge of the ages of individuals involved can help assess the likely effect on breeding populations.