Intraclutch variation in egg size of Canada geese

Abstract

Variation in egg size relative to laying sequence was examined for clutches of captive and wild western Canada geese (Branta canadensis moffitti). Eggs laid in the middle of a sequence were very similar in size and were larger than the first and last eggs of a clutch, which did not differ. Intraclutch variation in egg size in Canada geese may be caused by hormonal changes during egg formation and at the onset of incubation.