SPATIAL MEMORY IN A FOOD STORING CORVID .1. NEAR TALL LANDMARKS ARE PRIMARILY USED

This work suggests how food storing corvids use spatial memory to relo cate caches, and how they can do this after some landmarks surrounding caches have become hidden due to leaf fall, snow fall or plant growth . Experiments involved training European jays (Garrulus glandarius) to find buried food, the location of which was specified by an array of 12 landmarks. Tests were then performed with the array rotated, or wit h certain landmarks removed from the array. The.main findings were: (1 ) birds primarily remembered the position of the goal using the near t all landmarks (15-30 cm from the goal and 20 cm high); (2) birds obtai ned a sense of direction both from the landmark array and something ex ternal to the array; (3) birds did not use smell or marks in the surfa ce of the ground to find the goal. Memory of near tall landmarks is li kely to be functional for these birds since (a) nearer landmarks provi de a more accurate fix, and (b) taller landmarks are less likely to be completely obscured by snow fall, leaf fall or intervening vegetation . The work also demonstrates the use of G.I.S. software for the analys is and representation of animal search patterns.