Novelty and individual differences influence neophobia in orange-winged Amazon parrots (Amazona amazonica)

Abstract

Environmental enrichment both improves the welfare of captive animals and increases the validity of research using these animals. Enrichment programs have been shown to prevent or reduce the development of behavioral vices, stereotypy, and fearfulness. However, the protocols used in enrichment studies can be inconsistent: under some protocols, enrichments are provided but not changed, while under others, enrichments are rotated frequently. Enrichment experiments to date have also largely ignored the influence of individual differences on fearfulness. The aim of this study was to determine whether frequent rotation of enrichment objects (“high novelty”) was more effective than simply providing enrichment objects (“low novelty”) in reducing neophobia in juvenile orange-winged Amazon parrots and to determine whether individual differences significantly affected neophobia. Thirty-four juvenile orange-winged Amazon parrots received both an 11-week high-novelty (HN) treatment and an 11-week low-novelty (LN) treatment, which were given in random order. Neophobia was assessed by measuring birds’ latency to feed from a dish of highly favored food in the presence of various novel objects at approximately 10-day intervals. Our results indicate that the HN treatment significantly reduced neophobia in juvenile orange-winged Amazons. We also found that both individual variation in fearfulness and the novel object used for testing significantly affected birds’ latency to feed in the presence of novel objects. Our results indicate that rotation of enrichment objects is more effective than simply providing enrichments in reducing fearful behavior in parrots. The effect of rotating enrichments was strong enough to overcome approximately four-fold differences in birds’ latency to feed in the presence of different novel objects and even greater individual differences in neophobia. However, we also found that in highly fearful individuals, HN actually increased birds’ latency to feed in the presence of novel objects. Our results indicate that rotation of enrichment objects is more effective than simply providing enrichments in reducing fearful behavior in parrots, but that both enrichment object properties and individual differences should be carefully considered in the design of future enrichment studies and protocols.