Imitative pecking by budgerigars, Melopsittacus undulatus, over a 24 h delay
On video, budgerigars observed a conspecific demonstrator depressing a stopper by pecking or by stepping and then feeding from the box below. The observers were given access to the stopper, immediately after observation or following a 24 h delay, and we recorded the proportion of their stopper removal responses that were made by pecking and by […]
The direction and range of ambient temperature change influences yawning in budgerigars (melopsittacus undulatus)
Comparative research suggests that yawning is a thermoregulatory behavior in homeotherms. Our previous experiments revealed that yawning increased in budgerigars (Melopsittacus undulatus) as ambient temperature was raised toward body temperature (22→34 °C). In this study, we identify the range of temperatures that triggers yawning to rule out the possible effect of changing temperature in any […]
Plumage maintenance affects ultraviolet colour and female preference in the budgerigar
Elaborate or colourful feathers are important traits in female–mate choice in birds but little attention has been given to the potential costs of maintaining these traits in good condition via preening behaviour. While preening is known to be an important component of plumagemaintenance, it has received little attention with respect to colouration. We investigated whether […]
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 […]
Stereotypic behaviours in Melopsittacus undulatus: Behavioural consequences of social and spatial limitations
The demand for parrots for pet and scientific purposes is an increasing phenomenon. Yet, the cognitive complexity of these animals makes it difficult to fully satisfy their eco-ethological needs in captivity, and strategies commonly adopted for their husbandry are often unsuccessful in guaranteeing their wellbeing. In this study, we investigated the effects of environmental restrictions […]