Seasonal Decline in Clutch Size of the Barnacle Goose in Svalbard

Abstract

We examined seasonal decline in clutch size in the high arctic Barnacle Goose Branta leucopsis in Svalbard. Females that arrived first at the breeding ground nested first, had the longest prelaying period, produced the largest clutches and also had the longest incubation period. Nevertheless, their brood size at hatching was larger than late nesters. These results do not support the nutrient reallocation hypothesis which suggests that seasonal decline in clutch size in arctic nesting geese results from the mobilization of nutrient reserves during the period before egg laying. Instead, we propose that geese which arrive late at the breeding area spend relatively less of their reserves on eggs. They do this presumably to achieve synchronous hatching with early nesting birds and/or to prevent a late breeding season which may reduce gosling survival, adult survival and/or future fecundity.