Abstract: Egg weight increased with age (one to four years) in domestic geese and was followed by a senescent decline. However a more striking finding in adult geese was a within season decline in egg weight over the first eight weeks of lay, until baseline weight levels were achieved and were then maintained until the end of the laying season. The egg weight decline (wks 1-8) was significantly different from the baseline egg weight (wks 9-19) in adult flocks. The within season decline in egg weight is attributed to constraints on the ability of birds to acquire the necessary nutrients exogenously during the laying season, requiring the geese to utilise their limited endogenous reserves. The seasonal decline in egg weight is consistent with that in other waterfowl. However, a baseline egg weight level was found here that may be difficult to identify in wild geese, as in nature clutch completion is followed by incubation. The baseline level reflect the minimum egg weight necessary for viable gosling production. In one year old geese egg weight was lower from the genesis of egg laying through the first eight weeks and weight then steadily increased between weeks 9-19 tending towards the adult baseline levels. This is consistent with the maturation of one year old birds and shows that young geese are working towards the production of eggs with a viable egg weight.