Dorothy Cheney - US grants

Seyfarth 9520566 Abstract Alarm calls are vocal signals given by animals when they detect predators. Alarm calls are potentially costly, because they may attract predators. The questions of how such signals function, and how they evolve, are intriguing. Alarm calls given by nonhuman primates are of particular interest because they provide clear evidence of semantic communication outside of human language. This research has three objectives. The first is to examine the current function of alarm calls, and to elucidate their evolution. The second is to examine the semantic content of alarm calls, and the third is to determine what callers know about the predator-prey relations that exist among sympatric species. Studies will focus on red colobus monkeys, whose vocal and behavioral responses to tape playback of noises from potential predators and other prey species will be monitored in their natural environment. The results will increase our understanding of animal communication and insight into the evolution of semantic communication.

Abstract 9514001 Cheney The goal of this research is a better understanding of the vocal communication and social behavior of freeranging nonhuman primates. Focus will be on vocal communication for a variety of reasons: first, because of its potential relation to studies of language and cognition in humans; second, because vocalizations lend themselves to quantitative signal analysis and to experimental tests of specific hypotheses. Finally, prior research has shown that playback experiments can be used to test hypotheses not only about vocal communication per se but also about the cognitive mechanisms that underlie complex social interactions. Subjects are free-ranging baboons (Papio cynocephalus ursinus) living in the Okavango Delta, Botswana. Animals in the study population are fully habituated to human observers, are recognized as individuals, and have known reproductive histories. The proposal has five inter-related components. The first component of this proposal focuses on the use of vocalizations in reconciliation. After aggression, female baboons sometimes 'reconcile' by grunting to their lower-ranking opponents. Previous experiments have shown that these grunts function at least in part to reduce former victims' anxiety. A second component focuses on the acoustic structure and possible semantic content of grunts. Baboons appear to use acoustically different grunts in different social situations. The PIs plan a series of observations and experiments are planned to determine whether acoustically different grunt types designate specifically different information to baboons. A third component focuses on contact barks that appear to be exchanged between mothers and infants when they become separated in wooded areas. If these experiments indicate that mothers give contact barks primarily with respect to their own (rather than their infants') location, then they will add to a growing body of evidence suggesting that nonhuman primates do not call with the intent of providing inform ation to others. A fourth component focuses on the view that pair bonds are formed in response to the threat of infanticide by recent immigrant males. These experiments, however, are incomplete, largely because they must be conducted opportunistically during the weeks after a new, potentially infanticidal male has joined the group. A fourth goal of the research will be to complete these experiments. The final component focuses on the perception of cause-effect relations by nonhuman primates. Humans readily distinguish between two events that occur together because one caused the other and two events that occur together purely by association. Most research conducted to date suggests that monkeys do not apply causal reasoning when manipulating tools, though language-trained apes perform markedly better on similar experiments. Previous experiments conducted with this group of baboons, however, suggest that monkeys' ability to perceive cause-effect relations in the domain of social interactions may be quite well developed. Female baboons respond significantly more strongly to playbacks of vocal sequences that are causally anomalous than to those that are not. To investigate this question further, a series of experiments is proposed that make explicit predictions about both the strength and the timing of subjects' responses to particular call sequences. ***

Many animals give distinct vocalizations when feeding or upon discovering food. A number of hypotheses attempt to explain the evolution of these calls. One hypothesis argues that food calls are simply the involuntary consequence of excitement when the caller finds food. Alternatively, food calls may inform others about the type, location, or amount of food that has been discovered. The meaning of food calls to others, and hence their presumed function, is often inferred by observing the responses of nearby listeners. However, calls that elicit the same response may be caused by different underlying mechanisms. Call meaning, in this sense, may be different from the signaler's and the recipient's perspective. The researchers propose field observations and experiments to study the causes of food-calling in wild white-faced capuchin monkeys living in Costa Rica. They will investigate how calling is influenced by (1) the presence or absence of an audience, (2) food quantity and subdivisibility, and (3) foraging context. Prior experience at the study site assures that the work can be completed in 12 months and that the experiments are feasible. Results will make a significant contribution to our understanding of the mechanisms that underlie vocal production in nonhuman primates. These data, in turn, will help to formulate theories about the evolution of human language.

DESCRIPTION (provided by applicant): The overall goal of this research is to understand the mechanisms that underlie the vocal communication and social behavior of nonhuman primates, in order to provide a comparative framework for studies on the evolution of language and human behavior. Subjects are free-ranging baboons (Papio cyncephalus ursinus) in the Okavango Delta, Botswana. The population is one of a few in the world where background data on matrilineal kinship, dominance rank, and reproductive history are available for almost every individual, and where animals experience high rates of predation and infanticide. Three studies examine the function of vocal communication and its relation to cognition. In one, we test the hypothesis that acoustically graded signals, supplemented by context, function to communicate specific information to others. A second project examines the acoustic cues that underlie male vocal displays in competitive interactions. A third tests whether baboons recognize the "directedness" of vocalizations and attribute some level of intent to signalers. All are designed to contrast non-human primate communication and cognition with human language, thereby exploring the extent to which monkeys may be used as animal models for the study of human communicative and cognitive disorders. Three additional studies use observations, playback experiments, and data from fecal steroids. The first two examine the relation among male testosterone, corticosterone, dominance rank, parental behavior, and aggression in a population where males compete at high rates and form long-term "friendships" with females. The second focuses on females, and examines the stress hormone corticosterone in relation to seasonality, dominance rank, reproductive state, and social support in a population where predation and stress appear to be seasonal, changes in the male dominance hierarchy often lead to infanticide, and females differ widely in dominance rank and family size. All three of these studies are designed to examine the causes and consequences of aggression and stress in a close primate relative of modern humans.

This Integrative Graduate Education and Research Training (IGERT) award supports a multidisciplinary graduate training program at the University of Pennsylvania designed to integrate the computational, cognitive and neuroscientific study of communication and communication systems, be they characterized as human-linguistic, animal or machine. The primary purpose is to create a new breed of communication scientists capable of integrating theoretical issues, methods, and formalisms that are currently distributed across graduate programs as diverse as anthropology, biology, computer science and engineering, linguistics, neuroscience, philosophy, and psychology. The intellectual merit consists of the two interrelated research themes that will unite and guide graduate training. The first theme emphasizes communication as a dynamical process, one that unfolds along multiple time scales varying from milliseconds (as in planning and understanding speech) to centuries (as in evolving dialects, languages, and systems of animal communication). The second theme emphasizes communication as a context-sensitive process, where contexts range from the physical setting and communicative history of a specific conversation, to the linguistic, social and technological assumptions of social groups. Trainees will be co-advised by a multidisciplinary faculty team and will commit to a five-year graduate training program, consisting of: (1) core disciplinary training in one of the current graduate programs above; (2) one-year cross-disciplinary training in a chosen second discipline, including completion of a publishable research project; (3) participation in a weekly interdisciplinary research meeting throughout the 5-year program; and (4) completion of an advanced course in the mathematical foundations of communication specifically designed for this program. Broader impacts of this program include applications in industry, technology, and clinical settings. IGERT is an NSF-wide program intended to meet the challenges of educating U.S. Ph.D. scientists and engineers with the interdisciplinary background, deep knowledge in a chosen discipline, and the technical, professional, and personal skills needed for the career demands of the future. The program is intended to catalyze a cultural change in graduate education by establishing innovative new models for graduate education and training in a fertile environment for collaborative research that transcends traditional disciplinary boundaries.

In some primate species, it is common for individuals to leave the group in which they were born to join a different group (dispersal), but the evolutionary reasons dispersal are not completely understood. Primates exhibit high levels of inter- and intra-specific variation in dispersal, and there are costs associated with unfamiliar locations and/or aggressive competitors. Many models attempting to explain the evolution of dispersal have proposed a tight link among dispersal patterns, mating systems, and life history traits. Developing a better understanding of how social and mating systems influence and are influenced by dispersal patterns is essential for understanding the evolution of social and mating systems in primates, including humans. This project will study primate dispersal in a socially monogamous monkey species using genetic and hormone data collected non-invasively. This research is part of the Owl Monkey Project (OMP), a long-term initiative to promote research, conservation, and education in the Argentinean Chaco. Broader impacts include training of a female graduate student and undergraduate students in a STEM field, and support of international collaborations between the US and Argentina.

In this dissertation project, the co-PI will examine genetic, endocrine, and behavioral correlates of dispersal in free-ranging, socially monogamous owl monkeys of the Argentinean Chaco. The project will explore dispersal at the level of the community by genetically sampling individuals, and at the level of the social group by examining hormones and behavior in subadult males and females. Specifically, it will utilize genotype data from ~250 owl monkeys, behavioral data from 22 predispersing subadults, and steroid hormone data from ~1000 fecal samples to address current debates over the relationships between mating system and dispersal by evaluating inbreeding and competition avoidance hypotheses. These genetic, behavioral, and hormonal data will also be used to evaluate the costs and benefits of delaying dispersal in groups where a variable number of close kin may be present. Genetic data from this project also have strong potential to elucidate how a bisexually dispersing species may utilize differences in the average distance dispersed by each sex to avoid potential costs of inbreeding. The unique multi-level approach and integrative nature of this study of natal dispersal in a socially monogamous species has potential to illuminate the origins of dispersal and mating patterns in pair-bonded primates, including humans.