Alters- und Geschlechtsunterschiede in der Dispersion des Trauerschnäppers(Ficedula hypoleuca)

Summary

Pied Flycatchers settle in different places in successive years. The distances (from their birth- or previous breeding-places) at which ringed birds have been recovered in the following year are shown in columns e, f, g and h of the Table as cumulative recovery percentages. The results are divided according to the age and sex of the birds, and are shown also in the diagram. The following points should be noted:

• 1. Females returning for the first time (when one year old) show only moderate “Ortstreue“, and may settle up to at least 80 km from their birthplaces.

• 2. Males returning for the first time show the same degree of “Ortstreue“ as the one-year-old females, and have been found up to 50 km from their birthplaces.

• 3. Mostly older females show greater “Ortstreue“ than one-year-old females, though in some cases they may move as far or further than the young birds (up to 143 km).

• 4. Older males show marked “Ortstreue“ (the furthest recovery has been at only 700 m).

• 5. The mean distance of first-settlement of one-year-old birds (both male and female) is 4.5 km from their birthplace; the mean movement distance of older females is 2 km from their previous breeding-place, and that of older males is only 140 m.

• 6. Earlier conclusions on the dispersion of the Pied Flycatcher need to be modified and refined in the following way: The first-settlement of one-year-old males takes place as far from the birthplace as that of one-year-old females. Only after their first year do males show marked “Ortstreue“, and then differ in behaviour from females, which may move at any age.