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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.

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In the depleting density experiment it was found that the jays did respond to prey depletion and that the jays appear to use a hunting by expectation rule. These data suggest that the rule a predator uses depends on the distribution of prey.

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No description available.

Corvids are important seed and nut dispersers in North America. To date, the caching and recovery behaviors of four North American Corvids have been documented, n10st notably Clark1s Nutcracker (Nucifraga columbiana). Blue Jays (Cyanocitta cristata) are important dispersers of Quercus, Fagus, and Castanea nuts in eastern North America and their caching behavior in the wild has been well documented. Recovery of caches by the same individual Blue Jay that created the caches has not been demonstrated. In order to do this, I conducted a laboratory study in which I examined caching and recovery behaviors. I 'compared the performance of caching birds with noncaching birds and with a random foraging model. Blue Jays do return to their own caches with success rates higher than predicted by random searching and they also probe fewer sites than predicted by random. They also recover caches at success rates higher than non-caching birds searching for the same caches as well as probe fewer sites than the non-caching birds. There is a difference in probing patterns for recovered caches between caching birds and non-caching birds that suggests the use of spatial memory by caching birds and a difference in foraging strategies between the two groups. Cache recovery order does not exhibit either a primacy or recency effect and cache recovery order does not appear to correlate to nearest neighbor distance models. / Master of Science