Journal of Ethology

, Volume 27, Issue 1, pp 83–89 | Cite as

Improved walnut-feeding skills with experience in wood mice, Apodemus speciosus

  • Reina Takechi
  • Noriko Tamura
  • Fumio Hayashi


The wood mouse Apodemus speciosus can consume the hard-walled walnut species Juglans ailanthifolia. The mice gnaw holes on two sides of the shell and then pick the meat from the holes. However, not all mice are able to eat these walnuts, because the shells are extremely hard and the process is labour-intensive. To consume all of the meat it is more efficient to eat from holes on the raphe than to attempt to eat from other parts of the shell. We examined the effect of experience on the walnut-feeding skills of mice in the field. Feeding behaviours were compared among mice from habitats with and without walnut trees. Mice from habitats with walnut trees tended to consume nuts more efficiently than mice from habitats without walnut trees. We also observed the feeding behaviour of mice in an experimental area into which walnuts were artificially placed over a period of one year. This manipulation increased the proportion of mice that were able to eat nuts frequently and efficiently. Therefore, the walnut-feeding skills of mice improved with experience. Because individual mice acquired efficient feeding during the 14-day period of walnut conditioning, trial-and-error learning may be an important mechanism contributing to this behaviour.


Effects of food supply Feeding manner Food value Learning Seed predator Training 



The authors thank Y. Ino, T. Suzuki, and T. Kusano for discussions of various aspects of this study, and the staff of the Tama Forest Science Garden for their valuable support in the field investigations. The capture of mice was permitted by the Tokyo Metropolitan and Shizuoka Prefectural Governments. All procedures were approved by the Tokyo Metropolitan University Animal Ethics Committee.


  1. Abe H, Ishii N, Kaneko Y, Maeda K, Miura S, Yoneda M (1994) A pictorial guide to the mammals of Japan (in Japanese). Tokai University, TokyoGoogle Scholar
  2. Ainser R, Terkel J (1992) Ontogeny of pine cone opening behaviour in black rats, Rattus rattus. Anim Behav 44:327–336CrossRefGoogle Scholar
  3. Galef BG Jr (1980) Diving for food: analysis of a possible case of social learning in wild rats (Rattus norvegicus). J Comp Physiol Psychol 94:416–425CrossRefGoogle Scholar
  4. Galef BG Jr (2004) Approaches to the study of traditional behaviors of free-living animals. Learn Behav 32:53–61PubMedGoogle Scholar
  5. Galef BG Jr, Giraldeau LA (2001) Social influences on foraging in vertebrates: casual mechanisms and adaptive functions. Anim Behav 61:3–15PubMedCrossRefGoogle Scholar
  6. Gandolfi G, Parisi V (1973) Ethological aspects of predation by rats, Rattus norvegicus (Berkenhout), on bivalves, Unio pictorum L. and Cerastoderma lamarcki (Reeve). Boll Zool 40:69–74Google Scholar
  7. Kato J (1985) Food and hoarding behavior of Japanese squirrels. Jpn J Ecol 35:13–20Google Scholar
  8. McFarland D (1981) The Oxford companion to animal behaviour. Oxford University Press, OxfordGoogle Scholar
  9. Miguchi H (1993) Ecological features of seed dispersion by rodents. In: Kawanabe H, Washitani I, Ohgushi T (eds) Interaction of animals and plants (in Japanese). Heibonsha, Tokyo, pp 236–253Google Scholar
  10. Muñoz A, Bonal R (2008) Seed choice by rodents: learning or inheritance? Behav Ecol Sociobiol. doi: 10.1007/s00265-007-0515-y
  11. Parisi V, Gandolfi G (1974) Further aspects of the predation by rats on various mollusc species. Boll Zool 41:87–106Google Scholar
  12. Smith CC, Follmer D (1972) Food preferences of squirrels. Ecology 53:82–91CrossRefGoogle Scholar
  13. Tamura N (1998) Forest type selection by the Japanese squirrel, Sciurus lis (in Japanese). Jpn J Ecol 48:123–127Google Scholar
  14. Tamura N (2001) Walnut hoarding by the Japanese wood mouse, Apodemus speciosus Temminck. J For Res 6:187–190CrossRefGoogle Scholar
  15. Tamura N, Hayashi F (2008) Geographic variation in walnut seed size correlates with hoarding behaviour of two rodent species. Ecol Res. doi: 10.1007/s11284-007-0414-8
  16. Tatsukawa K, Murakami O (1976) On the food utilization of the Japanese wood mouse Apodemus speciosus (Mammalia: Muridae) (in Japanese). Physiol Ecol 17:133–144Google Scholar
  17. Terkel J (1996) Cultural transmission of feeding behavior in the black rat (Rattus rattus). In: Heyes CM, Galef BG Jr (eds) Social learning in animals: the roots of culture. Academic, San Diego, CA, pp 17–47Google Scholar
  18. Weigl PD, Hanson EV (1980) Observational learning and the feeding behavior of the red squirrel Tamiasciurus hudsonicus: the ontogeny of optimization. Ecology 6:213–218CrossRefGoogle Scholar
  19. Zar JH (1996) Biostatistical analysis, 3rd edn. Prentice Hall, Upper Saddle River, NJGoogle Scholar
  20. Zohar O, Terkel J (1996) Social and environmental factors modulate the learning of pine-cone stripping techniques by black rats, Rattus rattus. Anim Behav 51:611–618CrossRefGoogle Scholar

Copyright information

© Japan Ethological Society and Springer 2008

Authors and Affiliations

  1. 1.Department of BiologyTokyo Metropolitan UniversityTokyoJapan
  2. 2.Tama Forest Science GardenForestry and Forest Product Research InstituteTokyoJapan

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