From all these birds the following measurements were taken: total head length (THL) and bill depth at gonys (BD), with dial caliper to the nearest 0.1 mm, and tarsus plus toe length (TTL) and wing length (maximum chord) (WL), with stopped rule with accuracy 1 mm (Busse & Meissner 2015).
WL - wing length, THL - total head length, BD - bill depth at gonys. Discriminant equation Correctly sexed males females [D.sub.1] = 0.379THL + 0.379WL - 47.402 96.4 % 90.8 % [D.sub.2] = 0.397THL + 0.337BD - 40.744 96.4 % 89.5 % [D.sub.3] = 0.438THL - 40.890 95.7 % 90.8 % [D.sub.4] = 0.105WL - 39.434 93.5 % 68.4 % [D.sub.5] = 1.931BD - 21.097 87.0 % 75.0 % Discriminant equation Jackknife misclassification rate estimate [D.sub.1] = 0.379THL + 0.379WL - 47.402 6.4 % [D.sub.2] = 0.397THL + 0.337BD - 40.744 7.1 % [D.sub.3] = 0.438THL - 40.890 6.8 % [D.sub.4] = 0.105WL - 39.434 19.1 % [D.sub.5] = 1.931BD - 21.097 19.0 %