Biometrics, growth and sex ratios amongst Welsh DippersCinclus cinclus

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Abstract
Biometric data were collected from over 500 Dippers in mid and south Wales between 1978 and 1985. Mean wing lengths for both sexes were significantly shorter in first years than in older birds. For combined ages, males and females could be separated above and below wing length 92–94 mm; the sex ratio did not differ from 1:1. Wing lengths in both sexes were shorter than in Scandinavian Dippers, although Welsh males had significantly longer wings than males in south west Scotland. Body weights in both sexes increased during moult and prior to breeding, and a ‘condition factor'is suggested from regression of weight on wing length. Weights of nestlings indicated sex‐related differences, although it was impossible to sex every nestling using weight alone.