Giovanni Galizia, PhD

Professor für Zoologie und Neurobiologie

Universität Konstanz

Geboren 1963 in Rom
Studium der Biologie an der Freien Universität Berlin und der Zoologie an der University of Cambridge

Arbeitsvorhaben

Large-Scale Bird Navigation

Animals can navigate and find their way back to places they have been before. For example, honeybees will find their way back to a flower that has good nectar, and they can even communicate that position to fellow bees in their hives. Humans can find their way back to Villa Walther after a walk in the Grunewald. And migrating birds can travel thousands of kilometers to their winter sites with great accuracy. How do they form a map of the environment? What do they know about space? When they travel to a very distant place, do they remember salient places that they can use as landmarks when they fly the same trajectory a second or third time? Or do they use world-based coordinates, e.g. of the magnetic field of the earth? How does acquired memory interact with innate information?
We study Mantagu’s Harriers (Circus pygargus), a ground-nesting raptor that migrates to the African Sahel zone in winter. Our colonies are in Spain and suffer from modified land use and changing climate. We tag juveniles with GPS transmitters and follow their trajectories. What we have found so far is that juveniles, who cannot yet have any individual memory of the target area, fly independently from their family members to overwintering sites at different times and via distinct routes and choose sites hundreds of kilometers away from each other. The data indicates an innate knowledge of world geography. However, when returning to Spain, they find their place of birth and build their nests close to those of the previous year. This suggests acquired knowledge of where they were raised. In their subsequent years, they travel back to exactly the same place they went to in their first winter. However, in most cases, the route flown is different from year to year. Thus, we see that long-distance navigation uses knowledge of the world both innate (apparent in the first year) and acquired (apparent in subsequent years). More data are needed to understand the mechanisms and the ecological validity of these observations.

Recommended Reading

Berger-Geiger, Brigitte, Georg Heine, Ajayrama Kumaraswamy, and C. Giovanni Galizia (2022). “Changing Places: Spatial Ecology and Social Interactions of Female and Male Montagu’s Harrier (Circus pygargus) in the Spanish Extremadura.” Journal of Ornithology 163: 165–179. https://doi.org/10.1007/s10336-021-01914-9.
Menzel, Randolf, and C. Giovanni Galizia (2024). “Landmark Knowledge Overrides Optic Flow in Honeybee Waggle Dance Distance Estimation.” Journal of Experimental Biology 227 (21): jeb248162. https://doi.org/10.1242/jeb.248162.
Berger-Geiger Brigitte, Catarina Machado, Alfonso Godino, Manolo Calderón, and C. Giovanni Galizia (2025). “The First Year: Movements and Survival of Juvenile Montagu’s Harriers (Circus pygargus) in the Spanish Extremadura.” Preprint, Research Square, December 4. https://doi.org/10.21203/rs.3.rs-8253727/v1.

Kolloquium, 27.09.2022

Duftmusik im Bienengehirn

Wie werden Düfte im Gehirn verarbeitet?
Wie unterscheiden wir den Geruch eines Apfels von dem einer Banane – oder eines Stinkkäfers?
Welche Fragen gilt es nun zu beantworten?
Bienen kommunizieren im Stock über ihre Blütentrachen (die Nektar- oder Pollenquellen). Mit dem Bienentanz können sie ihren Schwestern Entfernung und Richtung mitteilen; Futterproben vermitteln den Geschmack und Duft an den Körperhaaren verrät den Blütenduft. Die Schwesterbienen folgen dem Tanz, fliegen zum angegebenen Ort und finden die Blüte mit dem richtigen Geruch.
In meiner Forschung untersuche ich die olfaktorische Kodierung im Gehirn von Insekten. Ich werde folgende Punkte ansprechen:
(1) Was für Experimente machen wir an der Universität Konstanz (wie kann man duftevozierte Gehirnaktivitäten messen)?
(2) Was bedeutet „Kodierung eines Dufts“ (musikalisch gesprochen: ist es ein Akkord oder eine Melodie? Oder beides?) und
(3) weiterreichende Fragen aus meiner Forschung am Wissenschaftskolleg (träumen Bienen, wenn sie schlafen?).