DOCSLIB.ORG

Causes and Consequences of Sibling Aggression in Nestling Ospreys (Wdionhaliaetus)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Causes and Consequences of Sibling Aggression in Nestling Ospreys (Wdionhaliaetus) CAUSES AND CONSEQUENCES OF SIBLING AGGRESSION IN NESTLING OSPREYS (WDIONHALIAETUS) by Marlene Machmer B .Sc., Simon Fraser University, 1988 THESIS SUBMIlTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in the Department of Biological Sciences O Marlene Machmer 1992 SIMON FRASER UNIVERSITY October 1992 All rights reserved. This work may not be reproduced in whole or in part, by photocopy or other means, without the permission of the author. APPROVAL Name: MARLENE MACHMER Degree: Master of Science Title of Thesis: CAUSES AND CONSEQUENCES OF SIBLING AGGRESSION IN NESTLING OSPREYS (PANDION HALIAETUS). Examining Committee: Chair: Dr. R. Mathewes, Professor 7 --. br. R.C -iate Professor, Senior Supervisw Department of Biological Sciences, SFU Department of Biological Sciences, SFU / - a .J.N.M. Smith, Department of Zoology, dverSig of ~riishColumbia of ~iolo~icalSciefi'ces, SFU I hereby grant to Simon. Fraser Unfvarsl$y the tlght to lend my ?thesis, proJsct or extended essay*(the ?It la of xhlch is shown below) to users of tha ShhFraser Unlverslty ~l br$ry, and to make partfnl or sfngla copies ant y for such users or f n response to a request f tam the l ibrary of any oihsr untverslty, or other $ducat tona l i nst f tut ion, on its own behalf or far one of its users. 1 further agrea that permission for-mulf.lp#s copylng of this work for scholariy purposes my be granted by me or tho Daan of Graduate Studios. it Is undersTood that,copyfng or pubflcatlon of ihls work for flnanclat galn, shall not be af towed without my wrltten permission. fftje of Thssfs/ProJect/Extended Essay Author: , .,- . a lslgnaturet ( name I Abstract Sibling aggression and brood reduction were studied in a population of Ospreys (Pandion haliaetus) breeding in the Kootenay region of British Columbia in 1989 and 1990. Almost all of the aggression observed occurred early in the nestling period when broods were less than 20 days of age. Senior siblings were more likely to use aggression and during the first 20 days of the nestling period, they received ~i~cantlygreater shares of food relative to their junior nestmates. After 20 days of age, aggression was rare and all brood members received equal shares of food. In cases of partial brood loss, over 90 percent of mortality involved junior chicks and all known mortality occurred when victims were less than 20 days old. Based on the pattern of food allocation and aggression within broods, and a general decline in aggression with nestling age, brood reduction appeared to be an outcome of aggression-mediated starvation. Brood reduction at successful nests occurred at rates of 12 and 31 percent in 1989 and 1990, respectively. Nestlings grew more slowly in the latter year, suggesting that mortality occurred in response to food limitation. There was tremendous variation in the level of sibling aggression observed between broods. Observations of broods under natural conditions provided little evidence that food amount, within-brood competitive asymmetry or brood size influenced this variation. Results of a controlled feeding experiment in 1989 and 1990 supported the food amount hypothesis for sibling aggression in nestling Ospreys. Broods were slightly but significantly more aggressive when they were hungry indicating that sibling aggression in this species is proximately influenced- - - by food shw-geta. Senior siblings took a greater share of food when they were hungry however this additional food did not come from the shares of younger nestmates. Instead, females compensated for the hunger of their broods by taking smaller shares for themselves and increasing the meal sizes fed to their broods. Experimental results also indicated that some of the inter-brood variation in aggression may be explained by differences in competitive asymmetries between nestmates. Aggression tended to decrease with an increase in brood age asynchrony and with an increase in brood weight asymmetry. The latter decline was significant. This effect is consistent with studies that have . .. manipulated brood hatching asynchrony or weight asymmetry and suggests that wuma&qp adjust their aggression levels based on the perceived level of competition within their broods. Acknowledgements I would like to express my thanks to the members of my committee for their help in improving this thesis. Ron Ydenberg, my senior supervisor, provided guidance and always found time for me during my impromptu visits. I thank him for his patience and understanding given the extended nature of my degree. Bernie Roitberg and Jamie Smith provided helpful criticism on earlier versions of this work. Thanks also to my collegues Scott Forbes and David Green both of whom worked through previous drafts of this thesis. Scott had useful suggestions during the planning of this project and lazy afternoon discussions with David helped me clarify my thinking. I owe special thanks to a number of enthusiastic assistants who I coaxed and who coaxed me up to Osprey nests. John Black and Ann Bussell persevered with me and the mosquitos through an extended field season in 1989. Their sympathetic pregnancies gave us all a good chuckle. My thanks also go to Kyla Super who volunteered her help during the fledgling study. David Green was tremendous help in 1990. His enthusiasm kept me going through a virtually sleepless field season. Over time, I discovered and came to share the secret to David's energy: yogwt icecream and chocolate waffle cones. Thanks to the staff at the Creston Valley Wildlife Management Area for their cooperation during this project. On behalf of the Ospreys, compliments to the Fish & Wildlife Branch in Nelson for the many frozen fish they supplied and thanks to Guy Woods in particular for his continued support of this project. Roger and Charlotte Perquy gave us a home in 1989 and made us feel part of their family. Roger's mirror and Charlotte's cinnamon buns were valuable additions to the study. Travis who made his presence felt at the beginning of the first field season, provided me with lucid insight on the theory and practice of parent-offspring conflict. I thank him for being a good-natured adventuresome baby and for teaching me the meaning of compromise. I hope he suffers no permanent damage as a resdt of the wrath inflicted on him by the senior sibling at nest N78. Last of all, I want to save special thanks for Chris Steeger. Not only was he "super dad" for a summer, but he also found time to collect data, struggle through numerous drafts of this thesis and put up with my endless thesis babble. I could not have done it without him. My research was supported by an NSERC Postgraduate Scholarship and a Graduate Fellowship Award from SN. The World Wildlife Fund and an NSERC operating grant to Ron Ydenberg provided additional financial support. TABLE OF CONTENTS Approval ............................................................................................ ii ... Abstract ............................................................................................. u1 Acknowledgements ............................................................................... v List of Tables ...................................................................................... ix List of Figures ..................................................................................... x I . GENERAL INTRODUCTION ......................................................... 1 I1. SIBLING AGGRESSION AND BROOD REDUCTION IN THE KOOTENAY OSPREY POPULATION Introduction ............................................................................... 4 Methods ................................................................................... 7 Results .................................................................................... 14 Extent. Timing and Variation in Sibling Aggression ................................ 14 Aggression and Food Allocation ...................................................... 19 Aggression and Nestling Growth ..................................................... 24 Nestling Growth and Mortality ........................................................ 24 Proximate Influences on Sibling Aggression ........................................ 29 Discussion ............................................................................... 34 Conclusions ............................................................................. 42 I11 . A TEST OF THE FOOD AMOUNT HYPOTHESIS FOR SIBLING AGGRESSION IN NESTLING OSPREYS Introduction ............................................................................... 43 Methods ................................................................................... 46 Results .................................................................................... 51 Hunger. Food Allocation and Aggression ....................: ....................... 51 vii Aggression and Relative Nutritional Condition ...................................... Aggression and Competitve Asymmetries Between Nestmates .................... Aggression and Brood Size ............................................................ Discussion ................................................................................ Conclusions .............................................................................. IV. GENERAL CONCLUSIONS ......................................................... LITERATURE CITED ................................................................. APPENDIX 1 ...........................................................................
Load more

Recommended publications
  • The Hidden Structure of Overimitation
    The hidden structure of overimitation Derek E. Lyons*†, Andrew G. Young‡, and Frank C. Keil* *Department of Psychology, Yale University, Box 208205, New Haven, CT 06520; and ‡Department of Psychology, University of Wisconsin, Brogden Hall, Madison, WI 53706 Edited by Susan E. Carey, Harvard University, Cambridge, MA, and approved October 18, 2007 (received for review May 11, 2007) Young children are surprisingly judicious imitators, but there are than in the utility of the actions that they copy. Others suggest that also times when their reproduction of others’ actions appears children overimitate ‘‘because they [see] the behavior of the dem- strikingly illogical. For example, children who observe an adult onstrator as intentional, even if they did appreciate that some parts inefficiently operating a novel object frequently engage in what of the demonstration were causally irrelevant’’ (ref. 10, p. 179). That we term overimitation, persistently reproducing the adult’s un- is, the intentionality of the adult’s action may constitute an implicit necessary actions. Although children readily overimitate irrelevant social demand for children, leading them to infer that they are actions that even chimpanzees ignore, this curious effect has ‘‘supposed’’ to imitate. A final possibility is that overimitation may previously attracted little interest; it has been assumed that chil- simply be a byproduct of habit. Overimitation may arise, in other dren overimitate not for theoretically significant reasons, but words, because imitation ‘‘remains habitual even in a specific rather as a purely social exercise. In this paper, however, we situation in which less fidelity would actually afford more effi- challenge this view, presenting evidence that overimitation re- ciency’’ (ref.
    [Show full text]
  • Andrea Deoudes, Kinetics: a Clock Reaction
    A Kinetics Experiment The Rate of a Chemical Reaction: A Clock Reaction Andrea Deoudes February 2, 2010 Introduction: The rates of chemical reactions and the ability to control those rates are crucial aspects of life. Chemical kinetics is the study of the rates at which chemical reactions occur, the factors that affect the speed of reactions, and the mechanisms by which reactions proceed. The reaction rate depends on the reactants, the concentrations of the reactants, the temperature at which the reaction takes place, and any catalysts or inhibitors that affect the reaction. If a chemical reaction has a fast rate, a large portion of the molecules react to form products in a given time period. If a chemical reaction has a slow rate, a small portion of molecules react to form products in a given time period. This experiment studied the kinetics of a reaction between an iodide ion (I-1) and a -2 -1 -2 -2 peroxydisulfate ion (S2O8 ) in the first reaction: 2I + S2O8 I2 + 2SO4 . This is a relatively slow reaction. The reaction rate is dependent on the concentrations of the reactants, following -1 m -2 n the rate law: Rate = k[I ] [S2O8 ] . In order to study the kinetics of this reaction, or any reaction, there must be an experimental way to measure the concentration of at least one of the reactants or products as a function of time. -2 -2 -1 This was done in this experiment using a second reaction, 2S2O3 + I2 S4O6 + 2I , which occurred simultaneously with the reaction under investigation. Adding starch to the mixture -2 allowed the S2O3 of the second reaction to act as a built in “clock;” the mixture turned blue -2 -2 when all of the S2O3 had been consumed.
    [Show full text]
  • Science Fiction Stories with Good Astronomy & Physics
    Science Fiction Stories with Good Astronomy & Physics: A Topical Index Compiled by Andrew Fraknoi (U. of San Francisco, Fromm Institute) Version 7 (2019) © copyright 2019 by Andrew Fraknoi. All rights reserved. Permission to use for any non-profit educational purpose, such as distribution in a classroom, is hereby granted. For any other use, please contact the author. (e-mail: fraknoi {at} fhda {dot} edu) This is a selective list of some short stories and novels that use reasonably accurate science and can be used for teaching or reinforcing astronomy or physics concepts. The titles of short stories are given in quotation marks; only short stories that have been published in book form or are available free on the Web are included. While one book source is given for each short story, note that some of the stories can be found in other collections as well. (See the Internet Speculative Fiction Database, cited at the end, for an easy way to find all the places a particular story has been published.) The author welcomes suggestions for additions to this list, especially if your favorite story with good science is left out. Gregory Benford Octavia Butler Geoff Landis J. Craig Wheeler TOPICS COVERED: Anti-matter Light & Radiation Solar System Archaeoastronomy Mars Space Flight Asteroids Mercury Space Travel Astronomers Meteorites Star Clusters Black Holes Moon Stars Comets Neptune Sun Cosmology Neutrinos Supernovae Dark Matter Neutron Stars Telescopes Exoplanets Physics, Particle Thermodynamics Galaxies Pluto Time Galaxy, The Quantum Mechanics Uranus Gravitational Lenses Quasars Venus Impacts Relativity, Special Interstellar Matter Saturn (and its Moons) Story Collections Jupiter (and its Moons) Science (in general) Life Elsewhere SETI Useful Websites 1 Anti-matter Davies, Paul Fireball.
    [Show full text]
  • CEAC 104 GENERAL CHEMISTRY Experiment 4 Effect of Concentration and Temperature on Rate of Reaction (Dissappearing Cross)
    CEAC 104 GENERAL CHEMISTRY Experiment 4 Effect of Concentration and Temperature on Rate of Reaction (Dissappearing Cross) Purpose: To observe the effect of concentration and temperature upon the rate of the reaction of sodium thiosulfate with hydrochloric acid. APPARATUS AND CHEMICALS: Sodium thiosulfate solution Thermometer Bunsen burner Hydrochloric acid Measuring cylinder Piece of paper Distilled water Conical flask Wire gauze THEORY: On the basis of experiments you've performed, you probably have already noticed that reactions occur at varying speeds. There is an entire spectrum of reaction speeds, ranging from very slow to extremely fast. For example, the rusting of iron is reasonably slow, whereas the decomposition of TNT is extremely fast. The branch of chemistry that is concerned with the rates of reactions is called chemical kinetics. Experiments show that rates of reactions in solution depend upon: 1. The nature of the reactants 2. The concentration of the reactants 3. The temperature 4. Catalysis. Before a reaction can occur, the reactants must come into direct contact via collisions of the reacting particles. However, even then, the reacting particles (ions or molecules) must collide with sufficient energy to result in a reaction; if they do not, their collisions are ineffective and analogous to collisions of billiard balls. With these considerations in mind, we can quantitatively explain how the various factors influence the rates of reactions. Concentration: Changing the concentration of a solute in solution alters the number of particles per unit volume. The more particles present in a given volume, the greater the probability of them colliding. Hence, increasing the concentration of a solute in solution increases the number of collisions per unit time and therefore, increases the rate of reaction.
    [Show full text]
  • The Case of Spatial Reorientation
    •¢.*~ " " r', ;: , ." ,; ! COGNITION ELSEVIER Cognition 61 (1996) 195-232 Modularity and development: the case of spatial reorientation Linda Hermer*, Elizabeth Spelke Department of Psychology, Cornell University, Uris Hall, Ithaca NY 14853, USA Received 27 March 1995, final version 20 February 1996 Abstract In a series of experiments, young children who were disoriented in a novel environment reoriented themselves in accord with the large-scale shape of the environment but not in accord with nongeometric properties of the environment such as the color of a wall, the patterning on a box, or the categorical identity of an object. Because children's failure to reorient by nongeometric information cannot be attributed to limits on their ability to detect, remember, or use that.information for other purposes, this failure suggests that children's reorientation, at least in relatively novel environments, depends on a mechanism that is informationally encapsulated and task-specific: two hallmarks of modular cognitive processes. Parallel studies with rats suggest that children share this mechanism with at least some adult nonhuman mammals. In contrast, our own studies of human adults, who readily solved our tasks by conjoining nongeometric and geometric information, indicated that the most striking limitations of this mechanism are overcome during human development. These findings support broader proposals concerning the domain specificity of humans' core cognitive abilities, the conservation of cognitive abilities across related species and
    [Show full text]
  • The Captive Lab Rat: Human Medical Experimentation in the Carceral State
    Boston College Law Review Volume 61 Issue 1 Article 2 1-29-2020 The Captive Lab Rat: Human Medical Experimentation in the Carceral State Laura I. Appleman Willamette University, [email protected] Follow this and additional works at: https://lawdigitalcommons.bc.edu/bclr Part of the Bioethics and Medical Ethics Commons, Criminal Law Commons, Disability Law Commons, Health Law and Policy Commons, Juvenile Law Commons, Law and Economics Commons, Law and Society Commons, Legal History Commons, and the Medical Jurisprudence Commons Recommended Citation Laura I. Appleman, The Captive Lab Rat: Human Medical Experimentation in the Carceral State, 61 B.C.L. Rev. 1 (2020), https://lawdigitalcommons.bc.edu/bclr/vol61/iss1/2 This Article is brought to you for free and open access by the Law Journals at Digital Commons @ Boston College Law School. It has been accepted for inclusion in Boston College Law Review by an authorized editor of Digital Commons @ Boston College Law School. For more information, please contact [email protected]. THE CAPTIVE LAB RAT: HUMAN MEDICAL EXPERIMENTATION IN THE CARCERAL STATE LAURA I APPLEMAN INTRODUCTION ................................................................................................................................ 2 I. A HISTORY OF CAPTIVITY AND EXPERIMENTATION .................................................................... 4 A. Asylums and Institutions ........................................................................................................ 5 B. Orphanages, Foundling
    [Show full text]
  • Reaction Kinetics: the Iodine Clock Reaction
    Bellevue College | Chemistry 162 Lab Manual Reaction Kinetics: The Iodine Clock Reaction Introduction The “clock reaction” is a reaction famous for its dramatic colorless-to-blue color change, and is often used in chemistry courses to explore the rate at which reactions take place. The color change occurs when I2 reacts with starch to form a dark blue iodine/starch complex. The ability to record the time at which the blue complex appears allows the rate of reaction to be determined accurately with a stopwatch. In this experiment, the rate law for a reaction is determined using the method of initial rates. The effect of concentration on the rate of this reaction is determined by measuring the initial reaction rate at several reactant concentrations. You will also examine the effect of a metal ion catalyst on the reaction rate. Lastly, you will investigate the effect of temperature on the rate of this reaction, which will allow you to determine the activation energy. The Clock Reaction - 2- The primary reaction to be studied is the oxidation of I by S2O8 (persulfate) in aqueous solution: - 2- 2- 2I (aq) + S2O8 (aq) I2(aq) + 2SO4 (aq) (slow, rate determining) Equation 1 2- This reaction will be run in the presence of a known amount of S2O3 (thiosulfate), which reacts very 2- 2- rapidly with I2. As long as S2O3 is present, I2 is consumed by S2O3 as fast as it is formed. This competing reaction prevents the I2 produced from our reaction of interest from reacting with starch, so no color change is observed until the thiosulfate is completely used up.
    [Show full text]
  • Experiment 5 Kinetics: the Oxidation of Iodide by Hydrogen Peroxide
    Experiment 5 Kinetics: The Oxidation of Iodide by Hydrogen Peroxide Goals To determine the differential rate law for the reaction between iodide and hydrogen peroxide in an acidic environment. To determine the activation energy and pre-exponential factor for the reaction. To determine the effect of a catalyst on the rate of reaction. Discussion When hydrogen peroxide is added to a solution of potassium iodide, the iodide ions are slowly oxidized according to the equation: Molecular equation: 2KI(aq) + 2HCl(aq) + H22 O (aq) → I 2 (s) + 2H 2 O(l) potassium iodide hydrochloric acid hydrogen peroxide iodine colorless colorless coloroless yellow -+ Net ionic equation: 2I (aq) + 2H (aq) + H22 O (aq) →I 2 (s) + 2H 2 O(l) iodide hydrogen peroxide iodine The rate law for this reaction should include the concentrations of iodide, hydrogen ion, and hydrogen perioxide. However, if the concentration of H+ is held constant throughout the experiment then its effect will not appear in the rate law. This results in a relatively simple rate law: – n m + p rate = k[I ] [H2O2] [H ] simplifies to: – n m + p rate = k'[I ] [H2O2] where k' = k[H ] Part 1: Determination of the Rate Law The rate law for the reaction between iodide ions and hydrogen peroxide can be determined by carrying out experiments in which the concentrations of iodide and peroxide are varied. For example, consider the following reaction and data: A + B → P Rate =k[A]n[B]m M Experiment [A]0 [B]0 Initial rate s 1 0.10 0.10 0.45 2 0.20 0.10 0.90 3 0.10 0.20 1.80 For this reaction, doubling the initial concentration of reactant A doubles the initial rate of reaction (experiments 1 and 2).
    [Show full text]
  • Solutions to Exercises Marked with Sg from the Book Introduction To
    Solutions to Exercises Marked with s from the book Introduction to Probability by Joseph K. Blitzstein and Jessica Hwang c Chapman & Hall/CRC Press, 2014 Joseph K. Blitzstein and Jessica Hwang Departments of Statistics, Harvard University and Stanford University Chapter 1: Probability and counting Counting 8. s (a) How many ways are there to split a dozen people into 3 teams, where one team has 2 people, and the other two teams have 5 people each? (b) How many ways are there to split a dozen people into 3 teams, where each team has 4 people? Solution: (a) Pick any 2 of the 12 people to make the 2 person team, and then any 5 of the remaining 10 for the first team of 5, and then the remaining 5 are on the other team of 5; this overcounts by a factor of 2 though, since there is no designated “first” team of 1210 5. So the number of possibilities is 2 5 =2 = 8316: Alternatively, politely ask the 12 people to line up, and then let the first 2 be the team of 2, the next 5 be a team of 5, and then last 5 be a team of 5. There are 12! ways for them to line up, but it does not matter which order they line up in within each group, nor does the order of the 2 teams 12! of 5 matter, so the number of possibilities is 2!5!5!·2 = 8316: 12! (b) By either of the approaches above, there are 4!4!4! ways to divide the people into a Team A, a Team B, and a Team C, if we care about which team is which (this is called a multinomial coefficient).
    [Show full text]
  • Ch2 Ethical Principles of Research
    2-1 Chapter 2. Ethical Principles of Research Historical Examples of Research With Ethical Concerns Tuskegee Syphilis Study The Milgram and Zimbardo Studies Research With Human Participants: Ethical Guidelines Ethical Principles and Code of Conduct Informed Consent: The Right to Know Sample Consent Form for a Student Research Project On the Use of Deception Field Research and Ethics Regulation of Human Research Research With Children and Mentally Challenged: Ethical Guidelines Thinking Critically About Everyday Information Research With Nonhumans: Ethical Guidelines Professional Behavior of the Investigator Testing Participants Integrity of the Data Plagiarism and Publication Case Analysis General Summary Detailed Summary Key Terms Review Questions/Exercises 2-2 Historical Examples of Research With Ethical Concerns Tuskegee Syphilis Study On the afternoon of May 16, 1997, President Clinton made a formal apology to Mr. Shaw, Mr. Pollard, Mr. Howard, Mr. Simmons, Mr. Moss, Mr. Doner, Mr. Hendon, and Mr. Key. These eight African American men were the remaining survivors of a medical research study sponsored by the United States government. In the words of President Clinton, the rights of these citizens and 391 others were “neglected, ignored and betrayed.” Syphilis is a venereal disease caused by the invasion of the body by a spirochete, Treponema pallidum. In its early stages, the infection is usually benign. A painless lesion develops at the site of the infection with secondary inflammatory lesions erupting elsewhere as the tissues react to the presence of the spirochetes. If untreated, an early syphilitic infection characteristically undergoes a secondary stage, during which lesions may develop in any organ or tissue throughout the body, although it shows a preference for the skin.
    [Show full text]
  • The End of Books—Or Books Without End? Front.Qxd 11/15/1999 9:04 AM Page Ii Front.Qxd 11/15/1999 9:04 AM Page Iii
    front.qxd 11/15/1999 9:04 AM Page i The End of Books—or Books without End? front.qxd 11/15/1999 9:04 AM Page ii front.qxd 11/15/1999 9:04 AM Page iii The End of Books—Or Books without End? Reading Interactive Narratives J. Yellowlees Douglas Ann Arbor The University of Michigan Press front.qxd 11/15/1999 9:04 AM Page iv Copyright © by the University of Michigan 2000 All rights reserved Published in the United States of America by The University of Michigan Press Manufactured in the United States of America c Printed on acid-free paper 2003 2002 2001 2000 4 3 2 1 No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, or otherwise, without the written permission of the publisher. A CIP catalog record for this book is available from the British Library. Library of Congress Cataloging-in-Publication Data applied for ISBN 0-472-11114-0 (cloth: alk. paper) front.qxd 11/15/1999 9:04 AM Page v Acknowledgments In 1986 John McDaid, then a fellow graduate student at New York University, suggested I meet Jay Bolter, who arrived bearing a 1.0 beta copy of Storyspace. When he opened the Storyspace demo document to show McDaid and I a cognitive map of the Iliad represented as a hypertext, my fate was clinched in under sixty seconds. I had seen the future, and it consisted of places, paths, links, cognitive maps, and a copy of afternoon, a story, which Jay also gave us.
    [Show full text]
  • Chimpanzees Play the Ultimatum Game
    Chimpanzees play the ultimatum game Darby Proctora,b,c, Rebecca A. Williamsona, Frans B. M. de Waalc,1, and Sarah F. Brosnana,b,d aPsychology Department, bLanguage Research Center, and dNeuroscience Institute, Georgia State University, Atlanta, GA 30302; and cLiving Links, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322 Contributed by Frans B. M. de Waal, November 29, 2012 (sent for review September 13, 2012) Is the sense of fairness uniquely human? Human reactions to of any study population, and these offers are often rejected (9, reward division are often studied by means of the ultimatum 10). This likely occurs because of the specific experimental set- game, in which both partners need to agree on a distribution for ting of the UG, which may reduce the fear of being ostracized, both to receive rewards. Humans typically offer generous portions allowing the Hadza participants to follow their self-interest. In of the reward to their partner, a tendency our close primate all cases, a given culture’s degree of cooperation, sharing, and relatives have thus far failed to show in experiments. Here we punishment influences offers in economic games (8, 11). What tested chimpanzees (Pan troglodytes) and human children on remains unclear is how other primates, including one of our a modified ultimatum game. One individual chose between two closest living relatives, the chimpanzee (Pan troglodytes), respond tokens that, with their partner’s cooperation, could be exchanged to these types of situations. Studying other primates may shed for rewards. One token offered equal rewards to both players, light on the evolutionary basis for the human tendency toward whereas the other token favored the chooser.
    [Show full text]