Black rhinoceros (Diceros bicornis) in US zoos: I. Individual behavior profiles and their relationship to breeding success

This is the first part of a multi-zoo study to analyze the effects of capti ve environments on black rhinoceros (Diceros bicornis) behavior, breeding s uccess, and well-being. We estimated the reliability and validity of a stan dardized method of cross-institutional assessment of the behavior of indivi dual rhinoceros. In 1994 and 1995, we asked zookeepers at 19 toes to rate t heir black rhinoceros (a total of 60 animals) on 52 behavior elements using a questionnaire. At 14 toes, at least two keepers rated all the black rhin oceros at their zoo. We used average differences in their ratings of the 52 behavior elements to determine the most reliably rated behavior elements. Fourteen elements were retained for further analysis. Based on their inter- correlations, we grouped these 14 behaviors into six behavior traits: olfac tory behaviors, chasing/stereotypy/mouthing, friendly to keeper fearful, pa trolling and dominant (to conspecifics). A behavior profile of each animal consisted of scores on these six traits that were the sum of the primary ke eper's ratings for each element in the group. To test the validity of these profiles, we compared scores on the six traits to the behavior of each rhi noceros during a standardized test of reactivity to a novel object and a no vel conspecific scent. Tests were videotaped and analyzed by one researcher . Frequencies and durations of behaviors observed during the tests were cor related with scores on all six rated behavior traits. Scores on friendly to keeper, dominant, and olfactory behaviors described differences between bl ack rhinoceros of captive/wild caught origin, age,and sex, respectively. Am ong successfully breeding males, scores on dominant and olfactory behaviors were negatively correlated with reproductive success, as was chasing/stere otypy/mouthing for females. To test the repeatability of these results, dur ing 1996-1997, we used a modified questionnaire to re-survey 70 black rhino ceros at 24 toes. Results of the second survey were also similar to those o f the first with respect to the behaviors that distinguish rhinoceros of di fferent origin, age, sex, and reproductive success. We conclude that rating s by keepers of behavior and temperament attributes can be used as reliable and valid cross-institutional descriptions of individual differences betwe en black rhinoceros. (C) 1999 Wiley-Liss, Inc.