Animal Cognition

, Volume 13, Issue 3, pp 431–441 | Cite as

Subjective value of risky foods for individual domestic chicks: a hierarchical Bayesian model

  • Ai Kawamori
  • Toshiya MatsushimaEmail author
Original Paper


For animals to decide which prey to attack, the gain and delay of the food item must be integrated in a value function. However, the subjective value is not obtained by expected profitability when it is accompanied by risk. To estimate the subjective value, we examined choices in a cross-shaped maze with two colored feeders in domestic chicks. When tested by a reversal in food amount or delay, chicks changed choices similarly in both conditions (experiment 1). We therefore examined risk sensitivity for amount and delay (experiment 2) by supplying one feeder with food of fixed profitability and the alternative feeder with high- or low-profitability food at equal probability. Profitability varied in amount (groups 1 and 2 at high and low variance) or in delay (group 3). To find the equilibrium, the amount (groups 1 and 2) or delay (group 3) of the food in the fixed feeder was adjusted in a total of 18 blocks. The Markov chain Monte Carlo method was applied to a hierarchical Bayesian model to estimate the subjective value. Chicks undervalued the variable feeder in group 1 and were indifferent in group 2 but overvalued the variable feeder in group 3 at a population level. Re-examination without the titration procedure (experiment 3) suggested that the subjective value was not absolute for each option. When the delay was varied, the variable option was often given a paradoxically high value depending on fixed alternative. Therefore, the basic assumption of the uniquely determined value function might be questioned.


Risk Chick Choice Bayesian estimation Value 



We express our sincere gratitude to Dr. Takuya Kubo (Hokkaido University) for his generous guidance and instruction on statistical computations, and Dr. Michael Colombo (University of Otago, New Zealand), Dr. Giorgio Vallortigara (University of Trento, Italy), and Dr. Tiaza Bem (Polish Academy of Science, Poland) for their critical comments on the manuscript. We would also thank anonymous referees for their critical reading, generous comments, and instructive suggestions, which were valuable in revising the paper. This study was supported by grants from the Japan Society for the Promotion of Science (JSPS; grant-in-aid for scientific research (C), #19500260) and the Japanese Ministry of Education, Culture, Sports, Science, and Technology (MEXT; grant-in-aid for scientific research on priority areas—Mobiligence #20033001) to T.M. Experiments were conducted under the guidelines and approval of the Committee on Animal Experiments of Hokkaido University. The guidelines are based on the national regulations for animal welfare in Japan (Law for the Humane Treatment and Management of Animals; after partial amendment No. 68, 2005).


  1. Aoki N, Csillag A, Matsushima T (2006) Localized lesions of arcopallium intermedium of the lateral forebrain caused a handling-cost aversion in the domestic chick performing a binary choice task. Eur J Neurosci 24:2314–2326CrossRefPubMedGoogle Scholar
  2. Barnard CJ, Brown CAJ (1985) Risk-sensitive foraging in common shrews (Sorex araneus L.). Behav Ecol Sociobiol 16:161–164CrossRefGoogle Scholar
  3. Bateson M, Kacelnik A (1995) Preferences for fixed and variable food sources: variability in amount and delay. J Exp Anal Behav 63:313–329CrossRefPubMedGoogle Scholar
  4. Bateson M, Kacelnik A (1996) Rate currencies and the foraging starling: the fallacy of the averages revisited. Behav Ecol 7:341–352CrossRefGoogle Scholar
  5. Caraco T, Martindale S, Whittam TS (1980) An empirical demonstration of risk-sensitive foraging preferences. Anim Behav 28:820–830CrossRefGoogle Scholar
  6. Caraco T, Blanckenhorn WU, Gregory GM, Newman JA, Recer GM, Zwicker SM (1990) Risk-sensitivity: ambient temperature affects foraging choice. Anim Behav 39:338–345CrossRefGoogle Scholar
  7. Gibbon J (1977) Scalar expectancy theory and Weber’s law in animal timing. Psychol Rev 84:279–325CrossRefGoogle Scholar
  8. Hamm SL, Shettleworth SJ (1987) Risk aversion in pigeons. J Exp Psychol Anim Behav Process 13:376–383CrossRefGoogle Scholar
  9. Hurly TA, Oseen MD (1999) Context-dependent, risk-sensitive foraging preferences in wild rufous hummingbirds. Anim Behav 58:59–66CrossRefPubMedGoogle Scholar
  10. Ichikawa Y, Izawa E-I, Matsushima T (2004) Exitotoxic lesions of the medial striatum delay extinction of a reinforcement color discrimination operant task in domestic chicks; a functional role of reward anticipation. Cog Brain Res 22:76–83CrossRefGoogle Scholar
  11. Izawa E-I, Zachar G, Yanagihara S, Matsushima T (2003) Localized lesion of caudal part of lobus parolfactorius caused impulsive choice in the domestic chick: evolutionarily conserved function of ventral striatum. J Neurosci 23:1894–1902PubMedGoogle Scholar
  12. Izawa E-I, Aoki N, Matsushima T (2005) Neural correlates of the proximity and quantity of anticipated food rewards in the ventral striatum of domestic chicks. Eur J Neurosci 22:1502–1512CrossRefPubMedGoogle Scholar
  13. Kacelnik A, Abreu FB (1998) Risky choice and Weber’s law. J Theor Biol 194:289–298CrossRefPubMedGoogle Scholar
  14. Kacelnik A, Bateson M (1996) Risky theories—the effects of variance on foraging decisions. Amer Zool 36:402–434Google Scholar
  15. Kacelnik A, Brunner D (2002) Timing and foraging: Gibbon’s scalar expectancy theory and optimal patch exploitation. Lean Motiv 33:177–195CrossRefGoogle Scholar
  16. Kalenscher T, Pennartz CMA (2008) Is a bird in the hand worth two in the future? The neuroeconomics of intertemporal decision-making. Prog Neurobiol 84:284–315PubMedGoogle Scholar
  17. Kass RE, Carlin BP, Gelman A, Neal RM (1998) Markov Chain Monte Carlo in practice: a roundtable discussion. Amer Statist 52:93–100CrossRefGoogle Scholar
  18. Koops MA, Giraldeau LA (1996) Producer–scrounger foraging games in starlings: a test of rate-maximizing and risk-sensitive models. Anim Behav 51:773–783CrossRefGoogle Scholar
  19. Lunn DJ, Thomas A, Best N, Spiegelhalter D (2000) WinBUGS – a Bayesian modelling framework: concepts, structure, and extensibility. Stat Comput 10: 325–337 (also refer to Scholar
  20. Matsushima T, Kawamori A, Bem-Sojka T (2008) Neuro-economics in chicks: foraging choices based on amount, delay and cost. Brain Res Bull 76:245–252CrossRefPubMedGoogle Scholar
  21. Mazur JE (1984) Tests of an equivalence rule for fixed and variable reinforcer delays. J Exp Psychol Anim Behav Process 10:426–436CrossRefGoogle Scholar
  22. Mazur JE (1986) Fixed and variable ratios and delays: further tests of an equivalence rule. J Exp Psychol Anim Behav Process 12:116–124CrossRefPubMedGoogle Scholar
  23. McCarthy MA (2007) Bayesian methods for ecology. Cambridge University Press, CambridgeGoogle Scholar
  24. McNamara JM, Houston AI (1987) A general framework for understanding the effects of variability and interruptions on foraging behaviour. Acta Biotheor 36:3–22CrossRefPubMedGoogle Scholar
  25. Reboreda JC, Kacelnik A (1991) Risk sensitivity in starlings: variability in food amount and food delay. Behav Ecol 2:301–308CrossRefGoogle Scholar
  26. Savory JC, Maros K (1993) Influence of degree of food restriction, age and time of day on behaviour of broiler breeder chickens. Behav Proc 29:179–190CrossRefGoogle Scholar
  27. Shafir S (1994) Intransitivity of preferences in honey bees: support for ‘comparative’ evaluation of foraging options. Anim Behav 48:55–67CrossRefGoogle Scholar
  28. Stephens DW (1981) The logic of risk-sensitive foraging preferences. Anim Behav 29:628–629CrossRefGoogle Scholar
  29. Stephens DW, Anderson D (2001) The adaptive value of preference for immediacy: when shortsighted rules have farsighted consequences. Behav Ecol 12:330–339CrossRefGoogle Scholar
  30. Stephens DW, Krebs JR (1986) Foraging theory. Princeton University Press, PrincetonGoogle Scholar
  31. Stephens DW, Paton SR (1986) How constant is the constant of risk-aversion? Anim Behav 34:1659–1667CrossRefGoogle Scholar
  32. Waser NM, McRobert JA (1998) Hummingbird foraging at experimental patches of flowers: evidence for weak risk-aversion. J Avian Biol 29:305–313CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  1. 1.Laboratory of Animal Behavior and Intelligence, Department of Biology Faculty of ScienceHokkaido UniversitySapporoJapan

Personalised recommendations