Increasing foraging times with appetitive and consummatory foraging enrichment in grey parrots (Psittacus erithacus)
Foraging enrichment is considered one of the most effective ways to enhance expression of species-typical behaviours and prevent the development of abnormal (repetitive) behaviours in captive animals. However, foraging enrichments for parrots have thus far not been able to approximate natural foraging time budgets nor completely eliminate abnormal behaviours such as feather damaging behaviour. This […]
Visual pigments and oil droplets from six classes of photoreceptor in the retinas of birds
Microspectrophotometric examination of the retinal photoreceptors of the budgerigar (shell parakeet), Melopsittacus undulatus (Psittaciformes) and the zebra finch, Taeniopygia guttata (Passeriformes), demonstrate the presence of four, spectrally distinct classes of single cone that contain visualpigments absorbing maximally at about 565, 507, 430–445 and 360–380 nm. The three longer-wave cone classes contain coloured oildroplets acting as […]