Atd. Bennett, SPATIAL MEMORY IN A FOOD STORING CORVID .1. NEAR TALL LANDMARKS ARE PRIMARILY USED, Journal of comparative physiology. A, Sensory, neural, and behavioral physiology, 173(2), 1993, pp. 193-207
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.