Data from: The effect of insect food availability on songbird reproductive success and chick body condition: evidence from a systematic review and meta-analysis

This repository contains data from “The effect of insect food availability on songbird reproductive success and chick body condition: evidence from a systematic review and meta-analysis” by Eliza M. Grames^1,2, Graham A. Montgomery³, Casey Youngflesh^3,4, Morgan W. Tingley³, and Chris S. Elphick¹ University of Connecticut, Department of Ecology and Evolutionary Biology, Storrs, CT, USA University of Nevada Reno, Department of Biology, Reno, NV, USA University of California Los Angeles, Department of Ecology and Evolutionary Biology, Los Angeles, CA, USA Michigan State University, Ecology, Evolution, and Behavior Program, East Lansing, MI, USA <strong>Abstract:</strong> Reports of declines in abundance and biomass of insects and other invertebrates from around the world have raised concerns about food limitation that could have profound impacts for insectivorous species. Food availability can clearly affect species; however, there is considerable variation among studies in whether this effect is evident, and thus a lack of clarity over the generality of the relationship. To understand how decreased food availability due to invertebrate declines will affect bird populations, we conducted a systematic review and used meta-analytic structural equation modeling, which allowed us to treat our core variables of interest as latent variables estimated by the diverse ways in which researchers measure fecundity and chick body condition. We found a moderate positive effect of food availability on chick body condition and a strong positive effect on reproductive success. We also found a negative relationship between chick body condition and reproductive success. Our results demonstrate that food is generally a limiting factor for breeding songbirds. Our analysis also provides evidence for a consistent trade-off between chick body condition and reproductive success, demonstrating the complexity of trophic dynamics important for these vital rates. <br> <strong>File List</strong> <em>README.txt</em> A plain text file containing information about the data files and variables they contain. <br> <em>effect-calculation.R</em> R script to calculate effect sizes for studies included in the meta-analysis based on the extracted statistics and data contained in raw_effect_data.xlsx and multiple-effects.csv <br> <em>study-characteristics-and-meta-analysis.R</em> R script to reproduce the analyses and figures from the manuscript including the descriptive characteristics of studies, meta-regressions, and meta-analytic structural equation model. Script imports study_characteristics.xlsx, effect_sizes.csv, effect-measurements.csv, output.nex, and BirdFuncDat.txt from https://doi.org/10.6084/m9.figshare.3559887.v1 <br> <em>effect-measurements.csv</em> Data file containing the list of ways in which researchers described bird body condition or reproductive success and the ways in which we reclassified those measures to more standardized measures <br> <em>effect_sizes.csv</em> Data file containing the calculated effect sizes from effect-calculation.R merged with study metadata <br> <em>habitat_groups.csv</em> Data file containing IUCN habitat groupings for the habitat types represented by studies included in the meta-analysis; used for plotting habitat types in a sensible order <br> <em>multiple-effects.csv</em> Data file indicating which effect should be used for studies where the same effect could be calculated different ways from the statistics and data reported in the original paper and effect sizes differed; the most reliable or unambiguous measure from each paper is selected <br> <em>output.nex</em> Phylogenetic tree output from VertLife for birds used as the backbone for plotting species phylogenetically <br> <em>raw_effect_data.csv</em> Data file containing test and summary statistics extracted from studies included in the meta-analysis; used to calculate effect sizes with effect-calculation.R <br> <em>study_characteristics.xlsx</em> Data file containing characteristics of studies included in the meta-analysis: citation, publication type, years of data collection, approximate latitude and longitude, study location, habitat classification and type, and focal species family, common name, and scientific name <br>