SEASONAL DECLINE IN CLUTCH SIZE OF THE BARNACLE GOOSE IN SVALBARD

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