Prospecting in the collared flycatcher: gathering public information for future breeding habitat selection? BLANDINE DOLIGEZ *†, TOMAS PA ¨ RT ‡ & ETIENNE DANCHIN * *Laboratoire d’Ecologie, Universite ´ Pierre et Marie Curie, Paris yCentre of Evolutionary Biology, Department of Animal Ecology, Uppsala University zDepartment of Conservation Biology, Swedish University of Agricultural Sciences, Uppsala (Received 27 September 2002; initial acceptance 29 November 2002; final acceptance 26 March 2003; MS. number: 7486) Visiting breeding patches can allow prospecting individuals to gather information on local patch quality to make optimal decisions about selecting a breeding habitat in the following year. This prospecting behaviour has been described in many bird species. However, the nature of the information gathered by prospectors often remains unknown. We collected data on prospecting behaviour in the collared flycatcher, Ficedula albicollis, a small hole-nesting passerine bird, to investigate whether prospectors could gather information on their conspecifics’ reproductive success, that is, ‘public information’. If they could, they would be expected to inspect conspecific nests, prospect at the time when public information is reliable, and be attracted to, and spend time at, successful sites. Prospecting at conspecific nests was frequent. Prospectors were mainly males, and prospecting activity closely matched the peak of nesting activity. The probability of observing a prospector at a nest increased with parental activity, measured by feeding rate and vigilance behaviour, but did not depend on direct measures of success of the inspected nest (nestling number and condition), or on female characteristics. Because feeding rate and vigilance behaviour were predictors of breeding success at fledging, prospectors were attracted to the most successful nests when cueing on conspicuous parental activity. Therefore, prospectors could gather accurate information on local conspecific reproductive success that may be used for breeding patch choice in the following year. We discuss alternative explanations for our results, and the need to test experimentally whether prospectors gather public information. We also discuss the role of breeding constraints on, and the origin of sex differences in, prospecting. Ó 2004 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved. For many species, breeding habitat quality varies at different spatial and temporal scales (Stephens 1989; Orians & Wittenberger 1991; Boulinier & Lemel 1996). Individuals thus need to gather information on potential breeding patches or sites, that is, ‘prospect’ (Reed et al. 1999), to make optimal decisions about selecting a breed- ing habitat (Wiens 1976; Cody 1985). There is growing evidence that individuals are able to track local breeding patch quality (Klopfer & Ganzhorn 1985; Badyaev et al. 1996; Petit & Petit 1996), by using different types of information (e.g. Stamps 1988; Switzer 1997; Doligez et al. 2002). Information used for breeding habitat selection and information-gathering behaviour have recently re- ceived considerably increased interest (e.g. Reed et al. 1999; Danchin et al. 2001; Stamps 2001), because of both their importance in shaping many evolutionary processes and their potential applications for conservation purposes (Curio 1996). Prospecting has been reported in numerous species (reviewed in Reed et al. 1999), and can influence processes both at the individual level (e.g. future re- productive success, Schjørring et al. 1999; Cam et al. 2002; dispersal decisions, Badyaev et al. 1996; or age at first breeding, Zack & Stutchbury 1992; Boulinier & Danchin 1997; Frederiksen & Bregnballe 2001) and at the popula- tion level (e.g. population dynamics and spatial distribu- tion, Danchin & Wagner 1997; Danchin et al. 1998; or population stability, Ruxton & Rohani 1999). Despite its potential major consequences, prospecting has been given little attention per se (Reed et al. 1999). This is probably because of technical difficulties linked to the observation and identification of prospectors. Thus, prospecting behaviour remains poorly understood Correspondence and present address: B. Doligez, Department of Evolutionary Ecology, Institute of Zoology, University of Bern, CH - 3012 Bern, Switzerland (email: blandine.doligez@esh.unibe.ch). T. Pa ¨rt is at the Department of Conservation Biology, Swedish University of Agricultural Sciences, Box 7002, S-75007 Uppsala, Sweden. E. Danchin is at the Laboratoire d’Ecologie CNRS-UMR 7625, Universite ´ Pierre et Marie Curie, 7 quai Saint Bernard, Ba ˆtiment A 7e `me e ´tage, Case 237, F-75252 Paris Cedex 05, France. 457 0003e3472/03/$30.00/0 Ó 2004 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved. ANIMAL BEHAVIOUR, 2004, 67, 457e466 doi:10.1016/j.anbehav.2003.03.010