STORAGE OF STONES BY JAYS GARRULUS-GLANDARIUS

The aims of this study were to test whether or not Jays Garrulus gland arius store stones and, if so, to examine the conditions under which t hey store stones. By directly observing the behaviour of five captive jays that were housed individually in flight cages, we found that ston es were stored only in the absence of food items or when food items we re no longer available to store and that there was a strong preference for storing stones that resembled acorns in both size and appearance (in terms of colour, shape and smoothness of the surface) and were und amaged rather than heavily chipped. These results are discussed in ter ms of Tinbergen's classic ethological model in which animals respond s electively to certain key features and ignore other features of the st imulus.