Examining Unihemispheric Sleep and its Potential Relation to Lateral Resting Behaviour and Unipedal Resting Stance in Caribbean Flamingos

Abstract

While much recent research has examined flamingo unipedal resting, as well as laterality in the resting behaviours of these birds, the phenomenon of unihemispheric sleep is not well documented in flamingos, and the potential relationship between unihemispheric sleep and these other aspects of flamingo resting behaviour has not been thoroughly explored. In the present report, unihemispheric sleep was studied in Caribbean Flamingos (Phoenicopterus ruber) (n=17) at the Philadelphia Zoo (Philadelphia, PA, USA). Specifically, we examined whether unihemispheric sleep, as measured by contralateral eye closure, is associated with unipedal resting and lateral behavioural side choice in resting Caribbean Flamingos. Results over three studies evidenced that Caribbean Flamingos do engage in unihemispheric sleep, and suggested that unihemispheric sleep is not related to unipedal resting or lateral neck-resting behaviour. Moreover, Harker and Harker's (2010) hypothesis that unipedal resting in flamingos is brought on by the impending onset of unihemispheric sleep was tested, with results failing to support this notion.