, Volume 49, Issue 1, pp 94–98

Experimental evidence of the territorial defense, hypothesis in insular Blue Tits

  • P. Perret
  • J. Blondel
Research Articles

DOI: 10.1007/BF01928800

Cite this article as:
Perret, P. & Blondel, J. Experientia (1993) 49: 94. doi:10.1007/BF01928800


Many insular vertebrates have unusually high population densities and are characterized by behavioural shifts including reduced territory size and reduced situation-specific aggressiveness. Compared to their mainland counterparts, Blue Tits on the island of Corsica exhibit many traits that fit the trends observed in crowded insular populations. We demonstrate from behavioural observations in aviaries and from hormone measurements that Corsican its are less aggressive than mainland ones. These shifts, as well as changes in reproductive patterns, support the defense hypothesis.

Key words

Blue Titdefense hypothesisinsularityaggressivenessbreeding traitssexual hormones

Copyright information

© Birkhäuser Verlag Basel 1993

Authors and Affiliations

  • P. Perret
    • 1
  • J. Blondel
    • 1
  1. 1.Centre d'Ecologie Fonctionnelle et EvolutiveCNRSMontpellier cedex(France)