Measurements of White-fronted Geese wintering at Slimbridge

Abstract

Between 1959 and 1963 181 White-fronted Geese caught alive or handled after death at Slimbridge in the months January to March were weighed and measured. As in other geese, males were found to be bigger than females. First-winter geese weighed less and had shorter wings than older geese, but were indistinguishable by length of bill, head or tarsus. In early March, 1959 the geese weighed were heavier than at any other time. Males and females were identified by examination of the gonads of dead birds and the cloaca of live ones: attempts to classify males and females on the basis of measurements alone did not give sufficiently reliable results. Weights and lengths are highly correlated. An investigation of the possibility of developing an index of 'condition' utilising these correlations showed that for statistical reasons such an index would be too unreliable to be of much value.