Establishment of juvenile marsh tits in winter flocks: an experimental study: an experimental study

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Abstract

Establishment in flocks by juvenile marsh tits, Parus palustris, was simulated in outdoor aviaries. Encounters between established and intruding juveniles were won by the established ones, irrespective of sex, size or age. As existing flock size increased, establishment became successively harder. Intruding females received less aggression from already established juveniles than did intruding males because: (1) established males largely ignored intruding females, whereas established females chased male and female intruders to the same degree and (2) the level of aggression from established males towards intruding males was higher than between established and intruding females. This sex difference among established individuals may be related both to future benefits in the form of availability of reserve breeding partners, and to costs in the form of future risks of becoming subdominant to the intruding individual. The difference between the sexes in the difficulty in becoming established was supported by field observations. Females seem more selective than males in their choice of flock or flock territory. Intruding juveniles, trying to become established, lost foraging time, which resulted in longer periods without food and lower intake rates than those of established juveniles.

Detaljer

Författare
Enheter & grupper
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Etologi
Originalspråkengelska
Sidor (från-till)586-595
TidskriftAnimal Behaviour
Volym38
Utgivningsnummer4
StatusPublished - 1989
PublikationskategoriForskning
Peer review utfördJa