Behavioral and physiological responses of captive gaur (Bos gaurus) to stress

Patrick Robert Thomas, Fordham University


This study examined the effects of environmental and social stressors on the herd dynamics, behavior and physiological functions of captive gaur (Bos gaurus). The project's three main components were: (1) an investigation of gaur behavior, (2) an evaluation of endocrine responses to stress via fecal cortisol monitoring, and (3) an assessment of physiological responses (heart rate and body temperature) to stressors. Individual gaur formed close affiliations with one or two herdmates, and with few exceptions, changes in the group's composition did not alter an animal's herd associations or its dominance ranking. Moving animals into novel environments or withholding food resulted in higher levels of aggression, but reducing the amount of space normally allotted to the animals did not increase agonism. Baseline levels of aggression were highest in the male herd. Fecal cortisol was analyzed by radioimmunoassay. Values ranged from 9.2-19.3 ng/g for individually-housed males and 7.5-19.7 ng/g and 11.3-21.5 ng/g for animals living in male and female herds, respectively. Animals isolated from conspecifics had slightly higher cortisol levels than when they were part of a social group. Fecal cortisol was not useful as a measure of social rank. Biotelemetry transmitters were implanted in female gaur to establish baseline heart rate and body temperature value ranges in unrestrained animals, and document changes in these physiological functions when animals were exposed to different environmental and social conditions. Mean heart rate for four gaur ranged from 49.3-57.7 beats per minute, and the mean body temperatures for two animals were 38.2 and 38.8$\sp\circ$C. Short-duration, adversive stimuli caused brief, three-fold increases in heart rate, but baseline rates returned once the stressors were removed. Moving gaur to novel environments or pairing them with non-affiliates also resulted in heart rate increases. Body temperature was not affected by short-term stressors. The onset of ovulation may be predictable based on temperature spikes exhibited by the gaur at 19-22 day intervals.

Subject Area

Zoology|Anatomy & physiology|Animals|Veterinary services|Forestry

Recommended Citation

Thomas, Patrick Robert, "Behavioral and physiological responses of captive gaur (Bos gaurus) to stress" (1997). ETD Collection for Fordham University. AAI9715512.