Diet Choices of Blue Jays (Cyanocitta cristata) as a Function of Time Spent Foraging

Optimal diet theory predicts choices among prey types. With sequential prey encounters, less profitable prey types may be rejected immediately because rejecting the prey item at hand increases the probability of encountering more profitable types. However, Lucas (1985) argued that at the end of a foraging bout, all encountered prey types should be accepted because the opportunity to encounter more profitable types is limited. We tested Lucas’s prediction in a simulation, allowing blue jays to hunt for two moth types differing in profitability. During the last min of both 10- and 20-min foraging bouts, the less profitable type was attacked more often than during the middle of the bouts; this is an end-of-the-bout effect. The less profitable type was also attacked more often at the beginning of the bouts; this is probably a sampling effect. Jays appear to integrate information about time spent foraging with information about relative prey profitability

Diet Choices of Blue Jays (Cyanocitta cristata) as a Function of Time Spent Foraging

Optimal diet theory predicts choices among prey types. With sequential prey encounters, less profitable prey types may be rejected immediately because rejecting the prey item at hand increases the probability of encountering more profitable types. However, Lucas (1985) argued that at the end of a foraging bout, all encountered prey types should be accepted because the opportunity to encounter more profitable types is limited. We tested Lucas’s prediction in a simulation, allowing blue jays to hunt for two moth types differing in profitability. During the last min of both 10- and 20-min foraging bouts, the less profitable type was attacked more often than during the middle of the bouts; this is an end-of-the-bout effect. The less profitable type was also attacked more often at the beginning of the bouts; this is probably a sampling effect. Jays appear to integrate information about time spent foraging with information about relative prey profitability

The effects of prey depletion on the patch choice of foraging blue jays (\u3ci\u3eCyanocitta cristata\u3c/i\u3e)

Blue jays (Cyanocitta cristata) were trained to hunt for non-cryptic moths presented in projected images. On each trial, the jays chose one of two patches to hunt in: (1) a uniform, “non-depleting” patch with constant prey density of 0.25; or (2) a “depleting” patch in which prey density changed during the foraging bout. In the depleting patch, the initial prey density was 0.50, declining to zero in a single step part-way through each foraging bout (session). The patch choices of the jays were greatly affected by these conditions. The jays chose the depleting patch early in the session, and then switched to the uniform patch. They obtained nearly all of the prey available. Analysis of the events preceding switches between patches suggested that the jays used different rules to switch out of each of the two patches

Integrating Cognitive Ethology with Cognitive Psychology

Cognitive ethology has been defined by Griffin (1978,1981, 1984) as the study of mental experiences in animals, restricting the domain of the field to phenomena thought to reveal intentionality, awareness, and conscious thinking. We argue that attempts to study these processes, while revealing impressive behavioral complexity, have proven unsuccessful in establishing the importance of mental experiences in determining animal behavior primarily because of the intractability of the problem. We suggest a different approach that draws upon the rich theory and sophisticated methodology of human and animal cognitive psychology while retaining an ecological and evolutionary perspective. Brief accounts of the conceptual underpinnings of cognitive psychology are presented as well as examples of empirical work, including the analysis of imagery in human and nonhuman animals. We hope our broad redefinition of cognitive ethology provides a rigorous framework within which to examine the role of cognition in ecologically relevant behavior

Response strategies in the radial arm maze: Running around in circles

The effects of the size of the central arena on the use of response strategies by rats on an eight~arm elevated maze were examined. The size of the central arena had no effect on accuracy, but the use of adjacent arms increased significantly with a larger central arena, regardless of the size of arena to which rats were first exposed. These results are interpreted in terms of foraging efficiency