title: Can video playback provide social information for foraging blue tits?
abstract: Video playback is becoming a common method for manipulating social stimuli in experiments. Parid tits are one of the most commonly studied groups of wild birds. However, it is not yet clear if tits respond to video playback or how their behavioural responses should be measured. Behaviours may also differ depending on what they observe demonstrators encountering. Here we present blue tits (Cyanistes caeruleus) videos of demonstrators discovering palatable or aversive prey (injected with bitter-tasting Bitrex) from coloured feeding cups. First we quantify variation in demonstrators' responses to the prey items: aversive prey provoked high rates of beak wiping and head shaking. We then show that focal blue tits respond differently to the presence of a demonstrator on a video screen, depending on whether demonstrators discover palatable or aversive prey. Focal birds faced the video screen more during aversive prey presentations, and made more head turns. Regardless of prey type, focal birds also hopped more frequently during the presence of a demonstrator (compared to a control video of a different coloured feeding cup in an empty cage). Finally, we tested if demonstrators' behaviour affected focal birds' food preferences by giving individuals a choice to forage from the same cup as a demonstrator, or from the cup in the control video. We found that only half of the individuals made their choice in accordance to social information in the videos, i.e., their foraging choices were not different from random. Individuals that chose in accordance with a demonstrator, however, made their choice faster than individuals that chose an alternative cup. Together, our results suggest that video playback can provide social cues to blue tits, but individuals vary greatly in how they use this information in their foraging decisions.
authors.affiliation: Department of Zoology, University of Cambridge , Cambridge , United Kingdom.
authors.forename: Liisa
authors.initials: L
authors.lastname: Hämäläinen
authors.affiliation: Department of Zoology, University of Cambridge, Cambridge, United Kingdom; Institute of Zoology, Zoological Society of London, London, United Kindgom.
authors.forename: Hannah M
authors.initials: HM
authors.lastname: Rowland
authors.affiliation: Centre of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyväskylä , Jyväskylä , Finland.
authors.forename: Johanna
authors.initials: J
authors.lastname: Mappes
authors.affiliation: Department of Zoology, University of Cambridge, Cambridge, United Kingdom; Department of Biosciences, University of Helsinki, Helsinki, Finland.
authors.forename: Rose
authors.initials: R
authors.lastname: Thorogood
keywords: Blue tits; Social information use; Video-playback