FIELD ENDOCRINOLOGY: SCIENTIFIC AND PRACTICAL ADVANCES TO ADDRESS OLD QUESTIONS

CONVENORS
Lukas Jenni

Swiss Ornithological Institute, 6204 Sempach, Switzerland

+41-41-462 97 10, lukas.jenni@vogelwarte.ch

Michaela Hau

Max-Planck-Institute for Ornithology, Vogelwarte Radolfzell

Schlossallee 2, D-78315 Radolfzell, Germany .

Fax: ++49 (0)7732 150142, Email: mhau@orn.mpg.de

DESCRIPTION
Over the last decades, the determination of hormones and their binding globulins in very small blood samples has become a routine. More recently, metabolites of hormones measured in droppings allow to estimate certain hormones non-invasively. The aim of this symposium is to demonstrate that some old and pressing questions can be tackled by investigating the hormonal status of birds in the field using a variety of approaches. Examples are the regulation of life history syndromes, the mediaton of trade-offs such as that between plumage colour and stress sensitivity, or between sexual ornaments and immunocompetence, or developmental effects that permanently shape the future phenotype. Furthermore, in the field of conservation biology, measurement of glucocorticoids have become the standard way of assessing the level of stress that birds are exposed to. Several studies have shown that birds can be physiologically stressed without showing behavioural changes. This is of foremost importance when assessing the impact of human disturbance that increasingly affects remote habitats. It will be explored what effect increased stress hormone concentrations have on fitness. We invite contributions that use endocrinological techniques to tackle questions in ecology, evolution or conservation biology in a field study.

KEYNOTE 1: Hau, M
Hormones, trade-offs and life history

KEYNOTE 2:   Jenni, L.  
Causes and effects of stress in birds: an introduction

Chastel, O.       

Reproduction and modulation of the stress response: testing the brood value hypothesis

Almasi,B., Roulin,A.;Jenni-Eiermann,S.;Jenni,L.  
Stress hormones elicit behavioural changes but not brood abandonment during reproduction

Riechert, J., Chastel, O., Becker, P.H   
Is the reproductive success of breeding common terns influenced by prolactin or corticosterone plasma levels?