Dept. of Behavioural and Cognitive Biology, Faculty of Life Sciences, University of Vienna

1. Does prenatal sound experience affect gene expression and vocalization behavior?

For species with imitative vocal learning, a core research challenge is to identify when learning begins. Traditionally, adequate developmental state of the neural substrates for vocal learning was thought be reached well after hatching in songbirds. New research shows that gene activity and vocal learning change as the consequence of sound experience in ovo. Zebra finch (Taeniopygia guttata) embryos exposed to prenatal conspecific song had increased ZENK activity and superb fairy-wren embryos (Malurus cyaneus) discriminated conspecific calls and produced a prenatally learnt call shortly after hatching. Nothing is known about individual in ovo response to sound in vocal non-learning systems. The aim of this study is to investigate if avian embryos from vocal learning and vocal non-learning lineages differ in their response to sound in ovo and if prenatal acoustical experience alters gene expression and vocalization behavior post-hatch. The study systems are vocal learning fairy-wrens (Maluridae) and vocal non-learning greylag geese (Anatidae). Using habituation/dishabituation research approaches, non-invasive prenatal digital heart rate monitors, and post- hatch blood sampling and vocalization recordings across life stages, this work will combine behavioral, bioacoustical, physiological and molecular approaches to measure the genetic and behavioral downstream effects of prenatal sound experience and response to sound across avian taxa.

2. Consistency in prenatal physiology across life stages and effects on personality

Individual differences in physiological characteristics or behaviours that are consistent and repeatable across contexts are known as 'consistent individual differences' and are commonly found across taxa. Consistent individual differences in resting metabolic rate (i.e., the number of calories that the body burns while resting) have been suggested to promote and support consistent individual differences in development and behaviour. Resting metabolic rate is an important proximate mechanism simply because all processes in the body require energy. Thus, the persistence of consistent individual differences may reflect behavioural and physiological trade-offs: individuals with higher resting metabolic rates may be more exploratory but may be more susceptible to starvation because of increased energetic requirements. Consistent individual differences in resting metabolic rate and behaviours may also represent different aspects of a general slow-fast life-history continuum, where fast-growing individuals with higher resting metabolic rate are expected to be more active, and have higher energetic needs, than those with slower metabolic rate. It is not clear if an embryo with a low metabolic rate develops into an adult with a slow metabolic rate. That is, there is a gap in knowledge about whether metabolic rate is consistent across life stages. A clear framework linking resting metabolic rate across life stages, and how metabolic rate is associated with activity versus exploration or other measures if individual differences, is missing. Building on preliminary data in the Northern Bald Ibis (Geronticus eremita) studied at the Konrad Lorenz Research Center, this project has the following aims: