Over-sized pellets naturalize foraging time of captive Orange-winged Amazon parrots (Amazona amazonica)

Parrots held in captivity experience distinctly different environmental demands, as compared to their wild conspecifics, particularly in regard to feeding. Cages equipped with computer-monitored infra-red beams (placed across a primary perch, in front of the feeder, in front of the drinking fount, and at the peak of the cage; interruption of a beam indicated a parrot's location) were used to supplement direct observation in characterizing activity budgets of adult male and female captive Orange-winged Amazon parrots (Amazona amazonica) fed pelleted diets. Parrots spent nearly all of their time perching, moving off the perch only a few times daily to drink and a few dozen times daily for pellet meals (each meal consisting of pellet retrieval and manipulation of the pellet(s) before swallowing). Such meals were temporally clumped, usually into 3–5 meal clusters per day, and clusters tended to be concentrated in morning and afternoon periods of a 12:12 LD light cycle, with a midday respite. Over-sized pellets formulated to be approximately 20–30 times larger than regular pellets (approximately 3–5 g each vs. 0.16 g each, respectively) exerted no detectable effect on the frequency distribution of off-perch bout lengths, but over-sized pellets dramatically increased post-pellet retrieval manipulation time approximately five-fold. In choice preference trials, parrots strongly preferred over-sized pellets to regular pellets, retrieving over-sized pellets approximately seven-times more often. Likewise, parrots offered only regular pellets removed 47.6 ± 6.4 g (mean ± SE) pellets from their feeder per day, but removed only 6.5 ± 2.0 of regular pellets, if over-sized pellets were offered concurrently. Finally, the option of manipulating/consuming over-sized pellets strongly affected use of wooden cube enrichment devices. During a 3-day period, parrots offered both regular and over-sized pellets reduced the mass of wooden cubes (through biting/chewing) by approximately 0.13 g; removal of the over-sized pellet option increased this amount 50-fold. These results suggest that parrots offered only regular-size pelleted diets are deprived of an opportunity to engage in foraging behavior. Offering parrots over-sized pellets or enrichment devices that provide foraging-like opportunities can dramatically reduce periods of inactivity and encourage a more naturalistic activity budget, thereby enhancing welfare.