Effects of 2 forms of environmental enrichment on a group of captive blackbucks (Antilope cervicapra): A pilot study

The aim of this preliminary study was to assess the effects of 2 forms of environmental enrichment (i.e., branched tree trunk and brushes) on the behavior of a group of 8 captive blackbucks. Animals were directly observed for 4 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 to 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 2 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 highlight some problems when observing this prey species.