Western scrub-jays ( Aphelocoma californica) use cognitive strategies to protect their caches from thieving conspecifics
Animal Cognition (2004) - Comment
pubmed: 12827547  doi: 10.1007/s10071-003-0178-7  issn: 1435-9448  issn: 1435-9456 

Nathan J. Emery, Joanna M. Dally, Nicola S. Clayton