Animal Cognition

, Volume 9, Issue 4, pp 369–376 | Cite as

Pilfering ravens, Corvus corax, adjust their behaviour to social context and identity of competitors

  • Thomas Bugnyar
  • Bernd Heinrich
Original Article


Like other corvids, food-storing ravens protect their caches from being pilfered by conspecifics by means of aggression and by re-caching. In the wild and in captivity, potential pilferers rarely approach caches until the storers have left the cache vicinity. When storers are experimentally prevented from leaving, pilferers first search at places other than the cache sites. These behaviours raise the possibility that ravens are capable of withholding intentions and providing false information to avoid provoking the storers' aggression for cache protection. Alternatively, birds may refrain from pilfering to avoid conflicts with dominants. Here we examined whether ravens adjust their pilfer tactics according to social context and type of competitors. We allowed birds that had witnessed a conspecific making caches to pilfer those caches either in private, together with the storer, or together with a conspecific bystander that had not created the caches (non-storer) but had seen them being made. Compared to in-private trials, ravens delayed approaching the caches only in the presence of storers. Furthermore, they quickly engaged in searching away from the caches when together with dominant storers but directly approached the caches when together with dominant non-storers. These findings demonstrate that ravens selectively alter their pilfer behaviour with those individuals that are likely to defend the caches (storers) and support the interpretation that they are deceptively manipulating the others' behaviour.


Raven Corvus corax Food caching Deception 



We thank M. Stöwe for assistance and R. Biegler, M. Bouton, G. Gaydon, C. M. Heyes, L. Huber, K. Kotrschal, I. M. Pepperberg, Chris Schloegl, and three anonymous referees for valuable comments. T. B. was funded by Erwin-Schrödinger grants J2064, J2225 and R31-B03 of the Austrian Science Fund. Permits for ravens include U.S. Federal Fish and Wildlife Permit Number MB689376-0, State of Maine Department of Inland Fisheries and Wildlife Permit 22077, and Vermont Fish and Wildlife Department Scientific Collecting Permit. The experiment described here was approved by the Institutional Animal Care and Use Committee at the University of Vermont (on November 1, 2002, Protocol No. 01–054), USA, where it was carried out.


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Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  1. 1.Department of BiologyUniversity of VermontBurlingtonUSA
  2. 2.Konrad Lorenz Research Station Gruenau and Department of Behaviour, Neurobiology, CognitionUniversity of ViennaViennaAustria

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