Discovering Culture Discovering Culture in Birds: the Role of Learning and Development

There are 9000 species of birds in the world; this is a report on two of them, cowbirds (Molothrus ater) and starlings (Sturnus vulgaris) Bird, 1999). We note the discrepancy in numbers to put into perspective the task of characterizing culture and social learning in 'birds " as a group. But as daunting as the task might sound, the diversity of behaviors and ecologies in birds offers a window on social learning, culture, and evolution that is hard to match. Bird species afford diverse opportunities for comparative analysis at the level of peas in a pod; a taxonomic point at which natural and sexual selection operate (King & West, 1990). Our interest in cultural processes in birds grew out of an interest in birds' songs: how songs develop and how they are used. Vocal learning and the transmission of song information across generations have been documented in many species (Freeberg, 2000; Kroodsma & Miller, 1996). Song is used in territorial defense and in the attraction of mates. Moreover, there is no question that birds make use of social and auditory learning to craft their repertoires. It is the nature of the crafting process that appeals to us, especially the need for social interactions to build an inventory of vocalizations and behaviors important for reproductive success. In our minds, culture is a verb; it is the " growing of biological material in a nutrient substance " (Merriman's Dictionary, 1993). The " material " is the organism along with its behaviors-to-be and the " nutrient substance " is the organism's developmental ecology. The cultural transmission of behaviors across generations is therefore the emergent product of an active organism and the nutrient substance. Such a metaphor may seem innocuous, but at its core is an assumption we believe is fundamental to theories of Discovering culture West, King, & White 3 culture or social learning. In the laboratory analogue, we assume different properties of the biological material/organism and of the medium/nutrients in which it is grown. Scientists focus most on changes in the former, not the latter. But what if the material affects the medium, the presumed passive source of growth? In a completely fictional example, what if bacteria being cultured produced heat that then affected the chemical properties of the medium, which then affected the nutrient value of the medium? Thus, the nature of the outcome is neither " in " the organism …