Staartbandering bij adulte Wespendieven Pernis apivorus geeft geen uitsluitsel omtrent sexe

Dark tail-bands in adult female Honey Buzzards are said to be more regularly spaced than in adult males. Moreover, dark bands on the basal half of the tail should be V-like in females and straight in males. These apparently diagnostic features were quantified, using 23 skins of males and 16 skins of females (in the collection of the Institute of Taxonomie Zoology in Amsterdam, cf. Appendix 1). Measurements were taken in mm along the rachis from a single central tail-feather (Table 1). Male Honey Buzzards showed on average a wider spacing between the subterminal and the following dark band (B in Figure 1), but the overlap between the sexes was extensive. The basal dark band (A in Figure 1) was on average wider in males than in females, but again with considerable overlap (Table 1). V-like basal bands were found in 12 out of 16 females (75%) and only in 6 out of 23 males (26%). None of these afore-mentioned features are therefore diagnostic of sex. Attributing moulted feathers to sex should thus be confined to secondaries and primaries.