DUNCAN C. BLANCHARD

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When a cat was presented to groups of 3 male and 2 female laboratory rats in the open area of a visible burrow system, the rats retreated to the burrow system and showed high levels of 18-24 kHz ultrasonic cries during the cat presentation and for 30 min following removal of the cat. Latency to make ultrasonic vocalizations, durations of these(More)
In mixed-sex rat groups maintained in visible burrow systems (VBS), consistent asymmetries in offensive and defensive behaviors of male dyads are associated with the development of dominance hierarchies. Subordinate males are characterized by particular wound patterns, severe weight loss, and a variety of behavioral changes, many of them isomorphic to(More)
In mixed-sex rat groups consistent asymmetries in offensive and defensive behaviors of male dyads are associated with the development of dominance hierarchies. Subordinate males can be differentiated from dominants on the basis of both agonistic and non-agonistic behaviors, wound patterns, weight changes. Their behavior changes suggest chronic defensiveness(More)
Social interactions serve as an evolutionarily important source of stress, and one that is virtually ubiquitous among mammalian species. Animal models of social stress are varied, ranging from a focus on acute, intermittent, or chronic exposure involving agonistic behavior, to social isolation. The relative stressfulness of these experiences may depend on(More)
The Mouse Defense Test Battery was developed from tests of defensive behaviors in rats, reflecting earlier studies of both acute and chronic responses of laboratory and wild rodents to threatening stimuli and situations. It measures flight, freezing, defensive threat and attack, and risk assessment in response to an unconditioned predator stimulus, as well(More)
The mammalian behavioral antipredator defense systems have been characterized in terms of reactions to present, localizable, threat stimuli: Analysis of the relationship between features of the predator and the environment, and specific defensive behaviors indicates that the latter can be predicted with a high degree of accuracy. A different set of(More)
In the visible burrow system model of chronic social stress, male rats housed in mixed-sex groups quickly form a dominance hierarchy in which the subordinates appear to be severely stressed. A subgroup of subordinates have an impaired corticosterone response after presentation of a novel restraint stressor, leading to their designation as nonresponsive(More)