The differential effects of four types of environmental enrichment on the activity budgets, fearfulness, and social proximity preference of Japanese quail

Environmental enrichment falls into four general categories: foraging opportunities, structural complexity, sensory stimulation/novelty, and social companionship. Each may have distinct behavioural effects. We examined the use of these four enrichment types, and their effects on activity budgets (foraging, general activity, pacing), social proximity preference (time spent observing companions through a window), and fear (flight distance in a predator surprise test, consumption of novel food) in adult Japanese quail. Foraging and structural enrichments were used extensively (29 and 26% of scans, respectively), as were the dustbaths available in all pens (16%). Use of enrichments and the dustbath was consistent over 24 h and over 17 d (partial r > 0.42, p < 0.001). Foraging enrichment increased foraging (F3,89 = 5.66, p < 0.01) and general activity (F3,89 = 4.75, p < 0.01). Foraging and structural enrichment decreased pacing (F3,89 = 6.33, p = 0.001). Novelty enrichment had no significant effects. Social housing reduced use of enrichments (enrichment treatment × housing type F3,89 = 3.30, p < 0.05) and dustbaths (F1,89 = 4.59, p < 0.05), suggesting resource monopolisation. Male birds ate more novel food (F1,45 = 5.43, p < 0.05) and spent more time observing social companions (F1,45 = 7.88, p < 0.01) than females, who used enrichments (F1,89 = 13.35, p < 0.01) and foraged more (F1,89 = 38.18, p < 0.001) and were more active than males (F1,89 = 34.83, p < 0.001). Results indicate that the use and behavioural effects of enrichment vary by enrichment type in caged quail. Foraging enrichment had the most positive behavioural effects while social housing had some negative effects. Furthermore, male and female quail may not benefit equally from enrichment.