Abstract
Wanderlust and its evolutionary consequences
Billions of birds migrate each year from their breeding grounds to their winter quarters, and back again. Although birds in general are preadapted in many ways to long-distance movements, those that migrate show many highly specialized features that differentiates them from related residents. Evolution to a migratory life style has occurred many times independently and can appear, and be reversed, in a relatively short time. Hence, solutions to the demands of long-distance migration may differ among lineages. However, some specific demands on energetics and aerodynamic performance produced strikingly similar physiological and morphological adaptations across a wide range of taxa.
One recurrent such pattern that has emerged in recent studies is that migrants have smaller brains than their resident relatives. As title and subtitle of this talk suggest, causal interpretations of this widespread association between brain size and migratory behavior differ. This raises, among other things, the general problem of explanations in evolutionary biology, and translating correlations into causation. I will elaborate on this theme with examples from various groups of birds, and different taxonomic levels, discussing various hypotheses related to sociality, foraging innovations and flexibility, energetics, and longevity. I also will show that the reduction in total brain size is the net effect of a massive reduction in volume of particular sections of the forebrain, while other parts of the forebrain even increase, and less peripheral parts of the brain are not affected at all and characterized by a remarkable constancy.
Having established the fact that forebrain sizes are consistently small in migrants the question of the cognitive consequences arises. I will discuss behavioral differences between migrants and residents and address the more general, and difficult, problem of the function of brain size in general. It turns out that there is remarkably little known about the functional consequences of small or large brains, and there is much conflicting evidence at the within and between species level. I will conclude with outlining possible future research directions.
Curriculum vitae
Hans Ch. Winkler
Konrad Lorenz Institute for Ethology
Austrian Academy of Sciences
Savoyenstraße 1A
A-1160 Wien, Österreich
Born 1945 in Wien
Education
Dr. phil, Universität Wien 1971.
Current positions
lecturer University of Salzburg, 1972 – present.
adj. Professor (Ethologie und Ökologie), Universität Wien, 1980 – present.
Senior Scientist at Konrad Lorenz Institute for Ethology Austrian Academy of Sciences
Positions held
Director of the Konrad Lorenz - Instituts für Vergleichende Verhaltensforschung der ÖAW, Wien, 1985-1987, 1991-2002.
Research assistant Institut für Limnologie der ÖAW, 1974-1984.
Chapman Fellow, Department of Ornithology, American Museum of Natural History, New York, 1973-1974
Research assistant at the Institut für Limnologie der ÖAW, Wien, Mondsee, 1972-1973
Research assistant at the Institut für Vergleichende Verhaltensforschung der ÖAW, Vienna, 1969-1972
Miscellaneous
180 plus publications.
Experienced in bird keeping and trapping, examining and marking live birds, statistics, data analysis, and computer programming.
Field studies abroad in USA, Sri Lanka, Philippines, Saudi Arabia, and Venezuela, among other countries.
Current scientific research projects: population genetics of migratory birds; experimental studies with nestbox populations; population ecological studies with mark-recapture techniques; evolution of brain architecture in migratory birds.
http://www.oeaw.ac.at/klivv/en/persons/hwinkler/