Bonobos assign meaning to food calls based on caller food preferences

Funding: The study was funded by an ERC starting grant PRILANG 283871 to KZ (https://erc.europa.eu/funding/starting-grants) and by the Swiss National Science Foundation (NCCR Evolving Language, grant agreement 51NF40_180888.Human communication relies heavily on pragmatic competence. Speech utterances are often ambiguous requiring listeners to use interaction history, shared knowledge, presumed intention and other contextual variables to make inferences about a speaker’s meaning. To probe the evolutionary origins of pragmatic competence we tested whether bonobos (Pan paniscus) can make inferences about the type of food available from listening to other group members’ food calls. We trained two group members to either prefer blue or pink chow and demonstrated these preferences to observers. A third group member served as an untrained control. In playback experiments, we broadcast the food calls of a trained demonstrator and the untrained group member to investigate whether subjects were able to infer which coloured chow was most likely available, based on the callers’ trained food preferences or lack thereof. As predicted, when hearing the untrained group member’s calls, subjects did not exhibit a bias, whereas they responded with a significant foraging bias when hearing a trained group member’s calls. These findings suggest that bonobos may take into account the idiosyncratic food preferences of others, although subjects probably differed in what they remembered.Publisher PDFPeer reviewe

Investigating self-recognition in bonobos : mirror exposure reduces looking time to self but not unfamiliar conspecifics

The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement no. 283871 and the Swiss National Science Foundation (Social learning in primate communication: 31003A_166458 / Coordinating joint action in apes: Testing the boundaries of the human interaction engine: CR31I3_159655).The question of whether animals have some sort ofself-awareness is a topic of continued debate. A necessary precondition forself-awareness is the ability to visually discriminate the self from others,which has traditionally been investigated through mirror self-recognition experiments.Although great apes generally pass such experiments, interpretations of resultshave remained controversial. The aim of this study was to investigate howbonobos (Pan paniscus) respond todifferent types of images of themselves and others, both before and afterprolonged mirror exposure. We first presented presumably mirror-naive subjectswith representations of themselves in three different ways (mirror image,contingent and non-contingent video footage) as well as representations ofothers (video footage of known and unknown conspecifics). We found thatsubjects paid significantly less attention to contingent images of themselves(mirror image, video footage) than to non-contingent images of themselves andunfamiliar individuals, suggesting they perceived the non-contingent self-imageas novel. We then provided subjects with three months of access to a largemirror centrally positioned in the enclosure. Following this manipulation,subjects showed significantly reduced interest in the non-contingentself-images, while interest in unknown individuals remained unchanged,suggesting that the mirror experience has led to a fuller understanding oftheir own self. We discuss implications of this preliminary investigation forthe on-going debate on self-awareness in animals.Publisher PDFPeer reviewe

Introduction: Performing Royal Power in Premodern Europe

This introduction considers the mediums and forms through which royal power was performed in premodern Europe, including civic entertainments, coronations, pageants, progresses, and the explosion of print culture that helped disseminate and shape many of these events. Power and performance have always been interlinked, with rulers and the ruled acutely aware of the necessity of ritual and image. This connection could be particularly important at times of crisis or political transition. The introduction makes connections between the articles in this special issue, which offer new perspectives on the participatory and dialogic nature of performing power in premodern Europe

Selective Out-Migration and the Estimation of Immigrants’ Earnings Profiles

This chapter focuses on the literature that estimates counterfactual career profiles of immigrants. It provides evidence on the scale of temporary migrations and their possibly selective character and explains in detail the methodological problems involved in estimating immigrant outcome profiles in the presence of selective outmigration. The chapter outlines the various ways in which to address these issues and provides an overview of the literature that estimates immigrant earnings profiles while accounting for the temporariness of many migrations

Seasonality, resource stress, and food sharing in so-called "egalitarian" foraging societies

Most discussions of food sharing among so-called "egalitarian" hunters and gatherers implicitly assume that, because all adult members of a group participate in the network of sharing, all must therefore be receiving portions of more or less equivalent nutritional worth. This assumption is questioned and five basic points are raised: (1) because fat is not uniformly distributed over the carcass of an animal and because it is depleted sequentially when an animal is stressed, certain individuals may receive nutritionally inferior portions of meat, with potentially serious health consequences for the recipients during seasonal or interannual periods when other food resources are in short supply; (2) even when sharing is quantitatively and nutritionally equitable, food taboos may block certain individuals from access to meat and/or fat, particularly children, women at critical stages in their reproductive life, and the elderly (however, in the case of pregnant women, such food taboos and seemingly inequitable sharing practices may have positive as well as negative consequences for the health and survivorship of the fetus or newborn infant by keeping maternal protein consumption below about 20% of total calories and by reducing the mother's risk of exposure to potentially teratogenic substances that may accumulate in animal tissues); (3) skilled hunters may acquire nutritionally more valuable parts than do other males by "snacking" at kill sites and through differential sharing; (4) food-sharing practices and food taboos vary widely among foragers, and this diversity may contribute to observed differences among groups in fertility and infant mortality patterns; and (5) the focus of anthropologists on the sharing of food, especially meat, as opposed to the sharing of a broad spectrum of social, political, economic, and sexual rights and privileges, is an overly narrow and potentially misleading perspective. In closing, the paper briefly discusses the utility of the term "egalitarian," concluding that the concept, by conflating ideology with actual behavior, may obscure rather than enhance our understanding of the origins and adaptations of foraging societies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28530/1/0000327.pd