Queuing for preferred territories: delayed dispersal of Siberian jays

1. Siberian jays (Perisoreus infaustus) can acquire breeding status along t wo routes. Some offspring dispersed in their first summer of life, but one- third of birds ringed as nestlings (39 of 117,40 broods) postponed dispersa l beyond their first winter and up to 3 years of age. 2. Birds dispersing in their first summer were able to settle in flocks out side their natal territory, while retained offspring appeared to be queuing for territorial vacancies in high-quality habitat rather than claiming one of the currently available vacancies of low quality 3. Males dispersing in their first year acquired territories close to human settlements, and with few low spruces. Reproductive success was low in tho se territories. Males with delayed dispersal acquired territories further a way from human settlements and with a high density of low spruces(< 15 m). Reproductive success was high in such territories. 4. A preference of all birds for territories characterized by high reproduc tive success, regardless of their timing of dispersal, suggests a causal re lationship to habitat characteristics. A non-breeding surplus of retained o ffspring had priority to vacancies at high densities and these birds claime d territories where reproductive success was high. At low densities and wit hout a non-breeding surplus it was possible for birds dispersing as yearlin gs to shift territory, and acquire vacant sites of higher quality. It was b irds settled in the territories with lowest reproductive success which shif ted, and at low population density their territories remained vacant. 5. Siberian jays postponed dispersal as a strategic trade-off where they fo rego dispersal options of low quality while queuing for high-quality habita t. However, a nepotistic parental behaviour towards retained offspring impl ies that fitness gains of delayed dispersal is not only a question of habit at quality.