Conspecific presence can indicate the location or quality of resources, and animals settling near conspecifics often gain fitness benefits. This can result in adaptive conspecific attraction during breeding habitat selection as demonstrated in numerous terrestrial, territorial birds. There is growing interest in using simulated conspecific social cues (e.g., decoys, broadcasted vocalizations) to manage bird distributions, yet it remains unclear when this approach is likely to succeed. We reviewed published studies to evaluate whether the strength of conspecific attraction in terrestrial birds is mediated by characteristics of species (life history traits), simulated cues (e.g., timing and duration), sites (e.g., quality), and how conspecific attraction was measured. We identified 31 experiments that simulated social cues and compared conspecific settlement between treatment and control sites. We then used phylogenetically controlled meta-regression to assess impacts of 19 moderators on settlement. Nearly all species included in these experiments were migratory passerines, and social cues generally had a strong, positive influence on their settlement decisions, as the odds of site occupancy were 3.12× (95% CI = 0.81, 11.69) greater in treatment sites relative to control sites. Within this group, conspecific attraction was evolutionarily conserved with ≥ 25.5% (CI = 5.1%, 65.4%) of the variance in treatment effects explained by phylogenetic relatedness. However, we found no evidence that any covariates influenced the response to social cues, and we posit this stems from limited research specifically designed to identify the mechanisms mediating conspecific attraction. We therefore developed a research agenda that provides a framework for testing mechanistic hypotheses regarding how cue characteristics, species traits, and spatial contexts may mediate attraction to conspecifics. Evaluating these hypotheses will greatly advance the field by helping managers understand when, where, and why simulating social cues can be used to enhance populations of species that are of conservation concern.

This dataset has been formatted using Tidy data principles (Wickham 2014). That is, each observational unit is stored in its own table, each observation is a row, and each variable is a column.  There is a meta-data tab included in the Excel workbook (data) that explains all variables in each table, and Appendix C of the manuscript's supplementary materials provides additional details about how moderators were aggregated and quantified.  We have also included the R code (dataAnalysis) required to import these data and perform all analyses in the manuscript.  Finally, the file output.nex is a random sample of 1000 Ericson backbone trees (Jetz et al. 2012; http://birdtree.org/) that is used to calculate an average phylogenetic tree in the analyses.

Jetz, W., G. H. Thomas, J. B. Joy, K. Harmann, and A. O. Mooers (2012). The global diversity of birds in space and time. Nature 491:444-448.

Wickham, H. (2014). Tidy data. Journal of Statistical Software 59:10.