The Zebra Finch: a synthesis revised

RichardZannwas a highly respected and passionate ornithologist with a first-rate reputation nationally and internationally for his work on Australian birds. Unassuming, modest and supportive to both students and colleagues, he was often referred to as the gentleman ofAustralian ornithology. In 1998, the significance of his long-term studies of austral birds and, in particular, the Zebra Finch (Taeniopygia guttata), was marked by the award of Australia’s most prestigious accolade for ornithology, the Serventy Medal (Anon. 1998). But probably the most longlasting impact Richard Zann had on austral ornithology was through his book The Zebra Finch: A Synthesis of Field and Laboratory Studies (Zann 1996), which has acted as a functional user’s guide for thoseworking on this remarkable little bird. Since the book’s publication, the species has become arguably the ‘lab rat’ of ornithology, used extensively worldwide in studies across the fields of evolutionary biology, behavioural ecology, physiology, neurobiology and genetics. The aim of this Special Issue, which is in memory of Richard, is to review much of the most notable work conducted on the Zebra Finch since 1996, and thereby create not only an update to Richard’s 1996 book, but a new synthesis of our understanding of this species. In February 2009, 173 people were killed in bushfires that raged across Victoria, Australia, particularly north-east of Melbourne. Tragically, Richard, his wife Eileen and their daughter Eva were among those killed (see Clarke 2009). This volume not only marks Richard’s contribution to ornithology over the last 40 years, but we hope is a positive response to this Black Saturday tragedy. Fourteen years ago, the genome of only one free-living organism had been sequenced. Now genomics is a field in its own right, and the Zebra Finch genome has been sequenced (Warren et al. 2010) – only the second bird genome available. In this Special Issue, Christopher Balakrishnan et al. discuss this milestone, the advantages of having access to a songbird genome, and the potential of genomic resources for the study of both the Zebra Finch and birds in general. Tim Birkhead reviews how the Zebra Finch became established as the species of choice for the study of sperm competition and what it has revealed about post-copulatory sexual selection. The ultimate evolutionary consequences of current levels of phenotypic variation in both wild and captive populations of Zebra Finches are explored by Barbara Tschirren and Erik Postma, who also address how far the species can be used to test evolutionary patterns and selection processes. Recently, the Zebra Finch has also been used to investigate the role maternal effects in determining offspring quality and success, and this is reviewed by Simon Griffith and Katherine Buchanan. The Zebra Finch has also become the model species for investigating the functional control of song learning and song production, as discussed by Mark Hauber et al., as well as the neural mechanisms underlying these traits, outlined by Sarah London and David Clayton in this issue. Zebra Finches are also used for the study of cognition, and the potential for future developments in this area is assessed bySueHealy et al.Although the ecology of the Zebra Finch has been extensively investigated, much less is known of this species’ physiological control of behaviour and reproduction within its arid environment. The current state of our understanding of how the physiological system has adapted to the unpredictable environmental conditions it experiences is summarised by Nicole Perfito in this issue. Collectively, these papers review the work conducted on this species in the past 15 years and confirm the fundamental importance of the Zebra Finch for so many areas of study in biological sciences. In bringing this collection of papers together, we acknowledge the wonderful contributions of many authors and reviewers and the support of the journal’sEditorial Board. TheZebra Finch is by no means a phoenix, but we are delighted to see the widespread international acknowledgement of the importance of Richard Zann’s contributions to ornithology in both hemispheres. We like to think that Richardwould have enjoyed this volume andwe publish it to mark his pivotal role in establishing the Zebra Finch as a model species in so many areas of avian science.