AVIAN HYBRIDISATION

CONVENORS
Prof. Dr. Christoph Randler
University of Education , INF 561-2, D-69120 Heidelberg, Germany, randler@ph-heidelberg.de

Prof. Dr. Jean Secondi
University of Angers, France jean.secondi@univ-angers.fr

DESCRIPTION
In recent times, studies on avian hybridisation have received much interest, both from a theoretical and macro-ecological perspective as well from thorough studies based on species pairs. The symposium aims at unifying both approaches so researchers dealing with discrete species and with meta-analytical data are invited to contribute. As pre-zygotic isolation barriers have been in the focus of research, especially work dealing with post-zygotic factors are welcome. Different isolation barriers may act to enforce speciation and to prevent hybridisation. Mechanisms constituting such barriers to gene flow may be either pre-zygotic, such as positive assortative mating among parental phenotypes, or post-zygotic, for example reduced fitness in one or both sexes of these hybrids, full or partial genetic incompatibility or differences in susceptibility to predation. Grant & Grant (1992) argue that pre-zygotic isolation mechanisms are more important in birds. However, avian hybrid zones are maintained by pre-zygotic and post-zygotic isolation mechanisms, although post-zygotic mechanisms have rarely been under investigation. Although hybridisation is an essential aspect of speciation we are still away from understanding the complete picture. The work presented here may be based on genetic studies as well as on field work carried out dealing with behaviour, ecology and evolution to provide a broad overview.

KEYNOTE 1: Randler, C. 
Avian hybrids – a macroecological perspective

KEYNOTE 2: Secondi, J., Bensch, S., Faivre, B.
Moving hybrid zones – interests and limits

Rubtsov, A.S., Panov, E.N. and Irwin, D.E.
Causes, dynamics and evolutionary role of natural hybridization: the case of interrelationship of Emberiza citrinella and  E. leucocephala.

Vabishchevich, A.P.  
Variability of the pied flycatcher’s (Ficedula hypoleuca) song in an eastern zone of sympatry with the collared flycatcher(F. albicollis)

Väli, Ü., Dombrovski, V., Treinys, R., Bergmanis, U., Daróczi, S.J., Dravecky, M., Ivanovski, V., Lontkowski, J., Maciorowski, G., Meyburg, B.-U., Mizera, T., Zeitz, R. and Ellegren, H.         
Widespread hybridisation with the Lesser Spotted Eagle threatens the Greater Spotted Eagle in Europe