Intraspecific social information use in the selection of nest site characteristics Olli J. Loukola a, * , Janne-Tuomas Seppänen b , Jukka T. Forsman a a Department of Biology, University of Oulu, Oulu Finland b Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä Finland article info Article history: Received 3 June 2011 Initial acceptance 15 July 2011 Final acceptance 18 November 2011 Available online xxx MS. number: 11-00463R Keywords: dominance great tit nest site choice nest visit Parus major social information Animals commonly acquire information about the environment by monitoring how others interact with it. The importance of social information use probably varies among species. In particular, many migratory birds breeding in northern latitudes rely on social information provided by resident tits when making important decisions and are able to copy or reject selectively the decisions of tits exhibiting good or bad fitness correlates, respectively. However, little is known about the role of social information use among resident tits. In a field experiment we tested whether great tits, Parus major, given a choice between two novel alternative features on adjacent nest sites, copy or reject conspecific choice represented by a simulated tit nest nearby, when the nest exhibits a high or low fitness correlate (clutch size). In contrast to the results in the interspecific setting, the portrayed fitness of the simulated nest did not affect tits’ nest site choices. However, the age of males had an effect, irrespective of the fitness correlate. Pairs with an old male preferred, while pairs with a young male tended to reject, the nest site choices of the simulated previously settled conspecifics. This result is surprising, as the final nest site choice in this species is presumably made by females, whose age and other phenotypic traits did not have an effect here. Our results imply stronger influence of the male great tits on nest site choice than previously thought. Dominance relationships and intraspecific competition are possible explanations for the age- dependent patterns in social information use. Ó 2011 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved. In a variable environment, genetically inherited information alone may not be sufficient for individuals to make optimal deci- sions such as where to breed, what to eat and whom to mate with, particularly when faced with novel situations. Thereby animals constantly need to acquire information about the environment, either personal information (e.g. by using a trial-and-error strategy) or social information (by monitoring how others interact with the environment; Danchin et al. 2004; Dall et al. 2005). Individuals should preferentially rely on personal informa- tion, but acquiring personal information may be impossible, for example because of phenological, cognitive, sensory or mobility limitations, or be prohibitively costly in terms of time and energy (Laland 2004; Kendal et al. 2005). Taking advantage of relatively cheap social information indeed appears to be a widespread phenomenon across the animal kingdom (Danchin et al. 2004; Seppänen et al. 2007; Goodale et al. 2010). Social information use has been found to affect various important aspects of animal behaviour, such as habitat choice (Doligez et al. 2002; Mönkkönen & Forsman 2002), foraging site decisions (Coolen et al. 2003), nest site feature choices (Seppänen & Forsman 2007), adopting strate- gies against predators (Zuberbühler 2000) and defending against brood parasitism (Campobello & Sealy 2011). Social information can even lead to traditions and cultural evolution, which may then affect genetic evolution as well (Boyd & Richerson 1985; Fragaszy & Perry 2003; Danchin et al. 2004). So far, most studies on social information use have concentrated on cognitive mechanisms and are conducted in laboratory condi- tions. Although the first field experiments on social information use were published decades ago (e.g. Alatalo et al. 1982; Stamps 1988), they have become more frequent only recently (e.g. Doligez et al. 2002; Galef 2004; Laland & Janik 2006; Aparicio et al. 2007; Boulinier et al. 2008; Reader & Biro 2010). While laboratory experiments provide controlled conditions allowing important discoveries about the cognitive mechanisms and strategies of social information use (Galef & Laland 2005), they shed less light on social information use in nature and its relationship with ecology. Therefore, field experiments are essential in determining whether and how social information use occurs in the life of free-living animals (Reader & Biro 2010) and how it interacts with other processes. Recent field experiments show that many migratory birds use resident tit species as sources of information in important breeding decisions (Mönkkönen & Forsman 2002; Seppänen et al. 2007). * Correspondence: O. J. Loukola, Department of Biology, University of Oulu, POB 3000, FI-90014 Oulu, Finland. E-mail address: olli.loukola@oulu.fi (O. J. Loukola). Contents lists available at SciVerse ScienceDirect Animal Behaviour journal homepage: www.elsevier.com/locate/anbehav 0003-3472/$38.00 Ó 2011 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.anbehav.2011.12.004 Animal Behaviour xxx (2012) 1e5 Please cite this article in press as: Loukola, O. J., et al., Intraspecific social information use in the selection of nest site characteristics, Animal Behaviour (2012), doi:10.1016/j.anbehav.2011.12.004