The purpose of the present series of experiments was to examine in some detail the characteristics of short-term memory in object discrimination learning set ( ODLS ) -experienced bluejays (Cyanocitt a Cristata ) . ODLS consists of the presentation of a series of two -choice simultaneous discrimination problems. Typically, non-correction procedures are used with position irrelevant throughout. Each new problem is defined by the introduction of a new pair of discriminative stimuli ODLS acquisition is defined as an increase in the speed of solving new problems accompanying experience with problem solving. Most comparative research performed with ODLS as the basic paradigm has concentrated on demonstration of ODLS acquisition . The only exceptions to this have been a large number of experiments with primates as subjects , particularly rhesus and other macaque species. The present experiment was designed to provide more analytic information about ODLS behavior in a species vastly different from the rhesus monkey.