Factors affecting survival of young Greylag Geese Anser anser and their recruitment into the breeding population

Abstract

Adult and young Greylag Geese have been neck-banded in a breeding area in southernmost Sweden since 1984 and have been followed intensively through the annual cycle. Fledging rate was correlated positively with the experience of parents and with early hatching; it was influenced also by choice by breeding area, wintering quarters and spring migration strategy of the parents. First year survival of fledglings was related to the same factors, but the heaviest goslings at the time of marking had a higher survival rate. Effects of wintering area and time of hatching were also apparent in the proportion of fledglings surviving to the age of three years. Greylag Geese started to recruit to the breeding population from the age of two, and recruitment age was lower for those reared in the best breeding area. Weight at the time of marking had a marked influence on recruitment, almost all recruits being above median size at marking. Moreover, the recruitment rate was influenced by the choice of winter quarters of their parents, recruitment rate was also correlated positively with family size.