Highlights

1. 1. The effect of 2 enrichments on the behavior of 8 captive blackbucks was studied
   2. The blackbucks interacted more with the tree-trunk than with the brushes
   3. Interactions decreased over time
   4. The enrichment induced little variation of the overall behavior of the group

Abstract

The aim of this preliminary study was to assess the effects of two forms of environmental enrichment (i.e., branched tree-trunk and brushes) on the behaviour of a group of eight captive blackbucks. Animals were directly observed for four hours a day (09:30-11:30 and 12:30-14:30), on days 1, 3, 6 (pre-enrichment phase, before the new individual was born), 8, 10, 15, 17 (pre-enrichment phase, after the birth of the new individual), 22, 24, 29, 31, 43, 64 (enrichment phase), using instantaneous scan sampling every minute. Video-recordings were also performed in days 24, 43, 64, from 09:30 to 11:00 and from 12:30-14:00, and analyzed using a continuous behavioral sampling method, for activities directed to the tree-trunk. Friedman and Wilcoxon tests were performed both on the total number of scans and on the percentage of scans in which the animals were not out-of-sight. The blackbucks interacted significantly more with the tree trunk than with the brushes (p=0.012). The duration of the interactions with the tree trunk declined over time (p<0.001). The animals increased their feeding activity and decreased their rumination while in the standing position in the enrichment phase in comparison with the two preceding phases. The results of this preliminary study suggest a slightly beneficial effect of the provision of a tree trunk for blackbucks as a form of environmental enrichment, and highlights some problems when observing this prey species.